CA1078865A - Isotopically labelled fatty acids - Google Patents
Isotopically labelled fatty acidsInfo
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- CA1078865A CA1078865A CA282,165A CA282165A CA1078865A CA 1078865 A CA1078865 A CA 1078865A CA 282165 A CA282165 A CA 282165A CA 1078865 A CA1078865 A CA 1078865A
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07D—HETEROCYCLIC COMPOUNDS
- C07D309/00—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only ring hetero atom, not condensed with other rings
- C07D309/02—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only ring hetero atom, not condensed with other rings having no double bonds between ring members or between ring members and non-ring members
- C07D309/08—Heterocyclic compounds containing six-membered rings having one oxygen atom as the only ring hetero atom, not condensed with other rings having no double bonds between ring members or between ring members and non-ring members with hetero atoms or with carbon atoms having three bonds to hetero atoms with at the most one bond to halogen, e.g. ester or nitrile radicals, directly attached to ring carbon atoms
- C07D309/10—Oxygen atoms
- C07D309/12—Oxygen atoms only hydrogen atoms and one oxygen atom directly attached to ring carbon atoms, e.g. tetrahydropyranyl ethers
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Abstract
TITLE OF THE INVENTION
Isotopically Labelled Fatty Acids ABSTRACT OF THE DISCLOSURE
The present invention relates to a process for the preparation of specifically labelled fatty acids and particularly to certain tetradeuterated or trideuterated palmitic acids. The novel compounds of the present inven-tion--specifically labelled palmitic acids including pal-mitic-5,5,6,6-d4 acid, palmitic-7,7,8,8-d4 acid, palmitic-16,16,16-d3 acid, and palmitic-11,11,12,12-d4 acid--are prepared by a synthetic scheme which involves a combina-tion of steps, including the alkylation of an intermediate containing a terminal acetylenic moiety and subsequently hydrogenating or deuterogenating the acetylenic bond in the presence of the soluble hydrogenation catalyst, tris-(triphenylphosphoro)rhodium chloride, to produce the corresponding saturated compound in which the acetylenic bond is saturated with either hydrogen or deuterium. Sub-sequent synthetic steps are utilized to convert functional substituents by known reaction steps to a carboxylic acid substituent, thus producing the novel compounds of the present invention.
Isotopically Labelled Fatty Acids ABSTRACT OF THE DISCLOSURE
The present invention relates to a process for the preparation of specifically labelled fatty acids and particularly to certain tetradeuterated or trideuterated palmitic acids. The novel compounds of the present inven-tion--specifically labelled palmitic acids including pal-mitic-5,5,6,6-d4 acid, palmitic-7,7,8,8-d4 acid, palmitic-16,16,16-d3 acid, and palmitic-11,11,12,12-d4 acid--are prepared by a synthetic scheme which involves a combina-tion of steps, including the alkylation of an intermediate containing a terminal acetylenic moiety and subsequently hydrogenating or deuterogenating the acetylenic bond in the presence of the soluble hydrogenation catalyst, tris-(triphenylphosphoro)rhodium chloride, to produce the corresponding saturated compound in which the acetylenic bond is saturated with either hydrogen or deuterium. Sub-sequent synthetic steps are utilized to convert functional substituents by known reaction steps to a carboxylic acid substituent, thus producing the novel compounds of the present invention.
Description
788~5 24 This invention relates to a process for the prep-aration of specifically labelled, saturated fatty acids 26 and to the process for the preparation of specifically . -.
27 labelled unsaturated acids. More specifically, it relates ~
~- 15996 ~'7l51~5 1 to multi-step syntheses of fatty acids in which the syn-
27 labelled unsaturated acids. More specifically, it relates ~
~- 15996 ~'7l51~5 1 to multi-step syntheses of fatty acids in which the syn-
2 thesis is designed to minimize the possibility of isotope
3 scrambling. The invention further relates to the novel
4 specifically labelled fatty acids prepared in accordance with the novel processes. Still more specifically, it 6 relates to a group of novel specifically deuterated pal-i mitic acids. It also relates to a novel method for pro-~ ducing such compounds by a synthesis which includes the g steps of (1) alkylating a compound having a terminal acetylenic moiety and a terminal functional substituent 11 convertible to carboxyl, and (2) catalytically deuterog-12 enating the triple bond of the formed acetylenic compound, 13 thus producing an intermediate having only one carbon-14 carbon linkage completely deuterated and having substan-tially no deuterium substitution elsewhere in the molecule.
17 The processes for producing labelled fatty acids 18 employed in the prior art involve the conversion o~ or 19 dinary fatty acids to their deuterated counterparts by hydrogen-deuterium exchange under conditions leading to 21 partial and/or complete replacement of hydrogen with deu-22 terium in a statistical basis., This type of deuterium-23 hydrogen exchange is dif~icult to control, and impossible 24 to limit to the preparation of specifically labelled fatty acids. Other methods involve the preparation of mixtures 26 of partially deuterated fatty acids and the attempted 27 separation of such mixtures into their component individual 28 compounds by complicated isolation procedures involving 29 gas-liquid chromatography and the like. Still other .
.
.
l procedures include the synthesis of unsaturated fatty 2 acids and the catalytic deuteration of such unsaturated 3 acids to produce the corresponding dideuterosubstituted 4 saturated fatty aeids having deuterium present in at least one specific location in the molecule. ~ drawback 6 to this procedure is the tendency to cause isotope scram 7 bling during the eatalytie deuteration of sueh eompounds.
8 Thus, in the course o the catalytic deuteration of such 9 compounds, one obtains, in addition to the product resul-ting from saturation of the double bond, a proportion of ll product in which other hydrogens of the substrate compound 12 have randomly been exehanged with deuterium. This results 13 in the preparation of a mixture of deuterated analogs, 14 whieh either eontaminate the speeifieally labelled produet or whieh must be separated by diffieult purifieation pro-16 cesses such as are mentioned hereinabove.
, 18 In accordance with the present invention, there 19 is provided a process for the preparation of speeifically labelled fatty acids using a synthetie sequenee whieh 21 combines the steps of alkylation of a terminal aeetylenie 22 substituent and hydrogenating or deuterogenating the aeet-23 ylenic bond in the presence of a selective and soluble 24 hydrogenation catalyst. The selection of the substrate eompounds for the alkylation reaction is based on the 26 desired position of deuterium in the final specifically 27 labelled aeid. This alkylation reaetion establishes the 28 position of the deuterium labelling relative to the carb-29 oxylic acid funetion in the final eompound.
` 15996 8~a;S
1 The process of the present invention is espe-2 cially use~ul for the preparation of specifically labelled ; 3 palmitic acids, which contain deuterium substituents spe-4 cifically affixed to certain positions of the carbon skeleton. ~hus, by judicious selection of the reacting 6 species, there are prepared in accordance with the present ~ invention, palmitic-5,5,6,6-d4 acid, palmitic-7,7,8,8-d4 8 acid, palmitic -16,16,16-d3 acid, and palmitic-11,11,12, 9 12-d4 acid. The process of the present invention may also be utilized in the preparation of other specifically deu-11 terated d4 fatty acids, especially d4 palmitic acids.
12 In accordance with the present lnvention, the 13 starting materials employed include one compound containin~
; 14 a terminal acetylenic moiety and a second compound con-taining a terminal halogen substituent. The halo compound 16 is the alkylating species, and the number of carbons in 17 the halohydrocarbon determines the length of the alkyl 1~ substituent attached to the terminal acetylene group and 19 therefore the ultimate specific position of deuterium atoms in the final acid. The starting material which con-21 tains the terminal acetylene mo1ety also contains~a carb-22 oxylic acid function or another functional substituent 23 readily convertible to carboxyl but unreactive under the 24 conditions of the alkylation reaction. One such substi-tuent is an hydroxyl substituent protected from reaction 26 by derivatization as a tetrahydropyranyl ether. Following 27 the alkylation, the tetrahydropyranyl ether is readily ; 28 sleaved to produce the corresponding hydroxy compound which 29 is carefully oxidized to the corresponding carboxylic acid compound in two stages using pyridium chlorochromate.
~ 15996 , 1 In another procedure, the hydroxyl substituent 2 is first converted to a bromo substituent by treatment ; 3 with a brominating agent such as carbon tetrabromide in 4 the presence of triphenylphosphine, which in turn is meta-thesized with an alkali metal cyanide, e.g., potassium, 6 to the corresponding nitrile. The nitrile compound is 7 then converted to the corresponding carboxylic acid by 8 hydrolysis with aqueous alkali, as for example, an alkali 9 metal hydroxide (sodium or potassium hydroxide 20~ solu-tion in water w/v).
11 In one specific embodiment of the invention, 12 the tetrahydropyranyl ether of 5-hexyn-1-ol is alkylated 13 by treatment with l-bromodecane in the presence of a strong 14 base such as butylithium to produce the intermediate 5-hexadecyl-l-ol. This acetylenic alcohol is then reduced 16 using deuterium gas in the pres`ence of tris-(triphenyl-17 phosphoro)rhodium chloride as a catalyst to produce the 18 corresponding saturated hexadecane-5,5,6,6-d4-1-ol OD.
19 The resulting saturated alcohol is then oxidized in two ZO stages using pyridinium chlorochromate to produce the 21 desired specifically labelled palmitic-5,5,6,6-d4~acid.
22 In a second specific embodiment of the inven-23 tion, the desired acid is produced directly in a two-step 24 sequence which comprises first contacting l-decyne with 6-bromo-hexanoic acid in the presence of butyl lithium to 26 produce directly the acetylenic acid, 7-hexadecynoic acid, 27 which is then converted directly to palmitic 7,7,8,8-d4 28 carboxylic acid by treatment with deuterium gas and tris-29 ~triphenylphosphoro)rhodium chloride as a catalyst.
~ .
" :
-. , . ` .
-: ,-, , ' , ` ` ` . ' ~ 7~5 15996 1 In a further specific embodiment of the present 2 invention, palmitic-16,16,16-d3 acid is prepared by first 3 contacting 10-undecyn-1-ol ~etrahydropyranyl e~her wi~h 4 1-bromopentane-5,5,5-d3 in the presence of butyl lithium to produce as a first intermediate, 10-hexadecyn-16,16,16-6 d3-ol and subsequently hydrogenating said aecynol in the 7 presence o~ tris-(triphenylphosphoro)rhodium chloride to 8 produce the desired product.
9 In a still further specific embodiment of the present invention, 10-undecyl-1-ol tetrahydropyranyl ether 11 is alkylated using l-bromobutane in the presence of butyl 12 lithium to produce 10-pentadecyn-ol, which is converted 13 to the tetradeutero compound pentadecan-l-ol 10,10,11,11-d4 14 by treatment with deuterium gas in the presence of tris-(triphenylphosphoro)rhodium chloride as a catalyst. The 16 said pentadecanol is then successively converted to the 17 corresponding halo compound, l-bromopentadecane-10,10,11, 18 11-d4 by treatment with triphenylphosphine and carbon 19 tetrabromiae, followed by metatheses of the bromopenta-decane with potassium cyanide to produce hexadecanitrile 21 11,11,12,12-d4 which in turn is hydrolyzed usin~ 20% aqueous 22 alcoholic sodium hydroxide solution to produce the desired 23 palmitic-11,11,12,12-d4 acid.
24 The novel, specifically labelled fatty acids of the present invention are valuable compounds used in many 26 kinds of specialized research work in addition to their 27 utility for the same purposes as the commercially available 28 palmitic acid. General applications include their use in 29 the study of reaction mechanisms, as tracers in the study of separation processes, and as model compounds for inves-31 tigation of the physical properties of labelled compounds.
.. .. . . . - . .. .. . .
~ 7~8~ l5996 1 They are also useful in the study of the naturally occur-2 ring unlabelled acids in biological systems, and as such 3 may be employed in the clinical diagnosis o~ conditions 4 which involve the production or abstraction of fatty acids.
They are also useful in the study of the metabolism and 6 biosynthe=i= of the corresponding unlabelled compound=.
:.
, .
~t7~b;S
; 1 EXAMPLE 1 ~ Palmitic 5,5,6,6-d~ Acid 3 Step A: 4-Chlorobutanol tetrahydropyranyl ether 4 C1~ ~
' A mixture of 4-chlorobutanol (21.7 9.) and p-6 toluenesulfonic acid (250 my.)in anhydrous ether is added 7 to dihydropyran (26 ml.) and the reaction mixture is stirred 8 at room temperature overnight. There is an initial mild g exothermic reaction. The solution is then diluted with ether (200 ml.) and washed twice with 0.1 M sodium carbonate 11 solution/ the ether layer containing the product is dried 12 with potassium carbonate and evaporated under reduced pres-13 sure, leaving a residue containing 4-chlorobutanol tetra-14 hydropyranyl ether. The residue is distilled, and the fraction at 74-76C./0.3 mm. ~g. is collected. Analytical ,, 16 data, nOm.r., m, 1.27-2.0, 8H; m, 3.22-4.12, 6H; s, 4.58, - 17 lH
18 Step B: 5-hexyn-1-ol-tetrahydropyranyl ether 1 9 I~C_C~
Under a nitrogen atmosphere, and with stirring, 21 acetylene is introduced into dry tetrahydrofuran (150 ml.l, 22 cooled, and maintained below 10C., while butyl lithium 23 (150 ml. of a 2.4 M solution in hexane~ is added dropwise. ;
~ ., .
24 After addition is complete, the mixture is matured for one 25 hour. A passage of acetylene gas through the mixture is ;
26 steadily maintained. A solution of 4-chlorobutanol tetra-. ;
~ 6~ 15996 1 hydropyranyl ether (50 g.) in dry hexamethyl phosphoric ~ -2 triamide (250 ml.) is added dropwise at such a rate that 3 the temperature did not exceed 20C. The reaction mixture 4 is stirred overnight at room temperature; ice, then water~
is added to dilute the mixture to one litre, and the mix-6 ture is extracted twice with ether. The ether solution is backwashed with water, dried with potassium carbonate, and 8 evaporated under reduced pressure to pro~uce a residue con-9 taining 5-hexyn~l-ol~tetrahydropyranyl ether. The residue is distilled, collecting the fraction at 66-69C. (0.25 mm.
11 Hg.), containing principally 5-hexyn-1-ol-tetrahydropyranyl 12 ether, b.p. 67-G8C./0.25 mm. IIg. Gas chromatographic 13 analysis demonstrates that the product contains 5% unreacted 14 starting material--4-chlorobutanol tetrahydropyranyl ether.
Step C: 5-~exadecynyl-1-ol 16 CH3~CH2)9C_C(CH2)40H
17 Under a nitrogen atmosphere, and with stirring 1~ and cooling, butyl lithium (66 ml. of a 2.4 M solution in 19 hexane) is added to a solution of S-hexyl-l-ol-tetrahydro-pyranyl ether (30 g.) in dry tetrahydrofuran (100 ml.), 21 ` at such a rate that the temperature remains below 10C.
22 The reaction mixture is stirred at 10C. for one hour, 23 then l-bromodecane (36.3 g.) in dry hexamethyl phosphonic 24 triamide (120 ml.) was added at a rate such that the tem-perature is maintained below 25C. ~he reaction is stirred 26 at room temperature overnight under an atmosphere of nitro-27 gen, then worked up by the addition of ice, then water, to 28 dilute the reaction to 700 ml., and is extracted twice with 29 ether. The combined ether extracts are washed several times with water, dried over potassium carbonate, and _g_ :
. . , : . - :
~ 7~8~ 15996 1 evaporated a-t reduced pressure. The residu~ is warmed at 2 50C. for two hours in methanol (200 ml.) containing p-3 toluenesulfonic acid (250 m~). The methanolic solution is 4 reduced to a quarter its volume, 0.1 M sodium carbonate solution (100 ml.) is added, and the mixture is extracted 6 with ether. The ether extract containing the product is 7 backwashed with 0.1 M sodium carbonate solution, then with 8 water, dried over magnesium sulfate, and evaporated under 9 reduced pressure. The low boiling material is mainly re-moved by distillation at 0.1 mm. (~ 80C.), and the residue 11 is chromatographed on silica gel, eluting with hexane, then 12 hexane containing 3% ethyl acetate, containing 10~ ethyl 13 acetate and finally 20% ethyl acetate. The purified prod-14 uct, 5-hexadecyl-1-ol, is characterized by n.m.r., CDC13 TMS, t, 3H, 0.88 ppm; m, 1.27, 16H; m, 1.6, 4H; m, 2.15, 16 4H; t, 3.63, 2H.
17 Step D: Hexadecane-5,5,6,6-d4-1-ol 18 CH3(cH2)9cD2(cH2)4 19 The hydroxyl group of 5-hexadecyl-1-ol is ex-changed by washing an ethereal solution of the compound 2] several times with excess deuterium oxide. The recovered 22 5-hexadecyn-1-ol-OD ~16 g.) is dissolved in 500 ml. of dry, 23 oxygen-free toluene; and under an atmosphere of nitrogen, 24 tris-~triphenylphosphoro~rhodium chloride (0.5 g~) is added as a catalyst. The acetylenic compound is reduced with D2 26 gas at 1 atmosphere pressure, taking up the calculated 27 volume of deuterium. The toluene solution is evaporated 28 under reduced pressure; the residue is extracted with ether ' .
' .
, , ' "' ' ' '." ' " ' ~ ' ''. ' ,' ' .~ ' , ' &~
1 several times; and combined extracts are filtered and evap-2 orated to dryness. The residue is distilled 125-128C.
3 (0.2 mm. Hg.), giving 14 g. of product.
4 Step E: Hexadecanal-5,5,6,6-d4 CH3(CH2)9CD2CD2(CH2)3CHO
6 In an appropriate flask fitted with a reflux 7 condensor is suspended 8.4 g. (86 mmole) of pyridinium 8 chlorochromate prepared as described in E. J. Corey and 9 J. William Suggs Tetrahedron Letters, p. 2647 (1975), in 100 ml. anhydrous methylene chloride. A solu-tion of 11 hexadecane-5,5,6,6-d4-1-ol (14 g., 57 mmole) in 20 ml.
12 methylene chloride is added in one portion to the stirred 13 solution. After 1.5 hours~ 100 ml. of dry ether is added 14 and the supernatant decanted from the black gum, which separates from the reaction mixture. The insoluble resi-16 due is then washed thoroughly three times with 50 ml.
17 portions of anhydrous ether; whereupon the insoluble black 18 gum residue becomes a black granular solid. The decanted 19 supernatant solution is combined with the ether extracts ;, .
containing the product and passed through a filter pad;
21 and the solvent is removed by distillation under reduced 22 pressure, leaving the product as a residual oil. The 23 product is purified by distillation at 115-120C. (0.15 24 mm.), thereby providing substantially pure hexadecanal-
17 The processes for producing labelled fatty acids 18 employed in the prior art involve the conversion o~ or 19 dinary fatty acids to their deuterated counterparts by hydrogen-deuterium exchange under conditions leading to 21 partial and/or complete replacement of hydrogen with deu-22 terium in a statistical basis., This type of deuterium-23 hydrogen exchange is dif~icult to control, and impossible 24 to limit to the preparation of specifically labelled fatty acids. Other methods involve the preparation of mixtures 26 of partially deuterated fatty acids and the attempted 27 separation of such mixtures into their component individual 28 compounds by complicated isolation procedures involving 29 gas-liquid chromatography and the like. Still other .
.
.
l procedures include the synthesis of unsaturated fatty 2 acids and the catalytic deuteration of such unsaturated 3 acids to produce the corresponding dideuterosubstituted 4 saturated fatty aeids having deuterium present in at least one specific location in the molecule. ~ drawback 6 to this procedure is the tendency to cause isotope scram 7 bling during the eatalytie deuteration of sueh eompounds.
8 Thus, in the course o the catalytic deuteration of such 9 compounds, one obtains, in addition to the product resul-ting from saturation of the double bond, a proportion of ll product in which other hydrogens of the substrate compound 12 have randomly been exehanged with deuterium. This results 13 in the preparation of a mixture of deuterated analogs, 14 whieh either eontaminate the speeifieally labelled produet or whieh must be separated by diffieult purifieation pro-16 cesses such as are mentioned hereinabove.
, 18 In accordance with the present invention, there 19 is provided a process for the preparation of speeifically labelled fatty acids using a synthetie sequenee whieh 21 combines the steps of alkylation of a terminal aeetylenie 22 substituent and hydrogenating or deuterogenating the aeet-23 ylenic bond in the presence of a selective and soluble 24 hydrogenation catalyst. The selection of the substrate eompounds for the alkylation reaction is based on the 26 desired position of deuterium in the final specifically 27 labelled aeid. This alkylation reaetion establishes the 28 position of the deuterium labelling relative to the carb-29 oxylic acid funetion in the final eompound.
` 15996 8~a;S
1 The process of the present invention is espe-2 cially use~ul for the preparation of specifically labelled ; 3 palmitic acids, which contain deuterium substituents spe-4 cifically affixed to certain positions of the carbon skeleton. ~hus, by judicious selection of the reacting 6 species, there are prepared in accordance with the present ~ invention, palmitic-5,5,6,6-d4 acid, palmitic-7,7,8,8-d4 8 acid, palmitic -16,16,16-d3 acid, and palmitic-11,11,12, 9 12-d4 acid. The process of the present invention may also be utilized in the preparation of other specifically deu-11 terated d4 fatty acids, especially d4 palmitic acids.
12 In accordance with the present lnvention, the 13 starting materials employed include one compound containin~
; 14 a terminal acetylenic moiety and a second compound con-taining a terminal halogen substituent. The halo compound 16 is the alkylating species, and the number of carbons in 17 the halohydrocarbon determines the length of the alkyl 1~ substituent attached to the terminal acetylene group and 19 therefore the ultimate specific position of deuterium atoms in the final acid. The starting material which con-21 tains the terminal acetylene mo1ety also contains~a carb-22 oxylic acid function or another functional substituent 23 readily convertible to carboxyl but unreactive under the 24 conditions of the alkylation reaction. One such substi-tuent is an hydroxyl substituent protected from reaction 26 by derivatization as a tetrahydropyranyl ether. Following 27 the alkylation, the tetrahydropyranyl ether is readily ; 28 sleaved to produce the corresponding hydroxy compound which 29 is carefully oxidized to the corresponding carboxylic acid compound in two stages using pyridium chlorochromate.
~ 15996 , 1 In another procedure, the hydroxyl substituent 2 is first converted to a bromo substituent by treatment ; 3 with a brominating agent such as carbon tetrabromide in 4 the presence of triphenylphosphine, which in turn is meta-thesized with an alkali metal cyanide, e.g., potassium, 6 to the corresponding nitrile. The nitrile compound is 7 then converted to the corresponding carboxylic acid by 8 hydrolysis with aqueous alkali, as for example, an alkali 9 metal hydroxide (sodium or potassium hydroxide 20~ solu-tion in water w/v).
11 In one specific embodiment of the invention, 12 the tetrahydropyranyl ether of 5-hexyn-1-ol is alkylated 13 by treatment with l-bromodecane in the presence of a strong 14 base such as butylithium to produce the intermediate 5-hexadecyl-l-ol. This acetylenic alcohol is then reduced 16 using deuterium gas in the pres`ence of tris-(triphenyl-17 phosphoro)rhodium chloride as a catalyst to produce the 18 corresponding saturated hexadecane-5,5,6,6-d4-1-ol OD.
19 The resulting saturated alcohol is then oxidized in two ZO stages using pyridinium chlorochromate to produce the 21 desired specifically labelled palmitic-5,5,6,6-d4~acid.
22 In a second specific embodiment of the inven-23 tion, the desired acid is produced directly in a two-step 24 sequence which comprises first contacting l-decyne with 6-bromo-hexanoic acid in the presence of butyl lithium to 26 produce directly the acetylenic acid, 7-hexadecynoic acid, 27 which is then converted directly to palmitic 7,7,8,8-d4 28 carboxylic acid by treatment with deuterium gas and tris-29 ~triphenylphosphoro)rhodium chloride as a catalyst.
~ .
" :
-. , . ` .
-: ,-, , ' , ` ` ` . ' ~ 7~5 15996 1 In a further specific embodiment of the present 2 invention, palmitic-16,16,16-d3 acid is prepared by first 3 contacting 10-undecyn-1-ol ~etrahydropyranyl e~her wi~h 4 1-bromopentane-5,5,5-d3 in the presence of butyl lithium to produce as a first intermediate, 10-hexadecyn-16,16,16-6 d3-ol and subsequently hydrogenating said aecynol in the 7 presence o~ tris-(triphenylphosphoro)rhodium chloride to 8 produce the desired product.
9 In a still further specific embodiment of the present invention, 10-undecyl-1-ol tetrahydropyranyl ether 11 is alkylated using l-bromobutane in the presence of butyl 12 lithium to produce 10-pentadecyn-ol, which is converted 13 to the tetradeutero compound pentadecan-l-ol 10,10,11,11-d4 14 by treatment with deuterium gas in the presence of tris-(triphenylphosphoro)rhodium chloride as a catalyst. The 16 said pentadecanol is then successively converted to the 17 corresponding halo compound, l-bromopentadecane-10,10,11, 18 11-d4 by treatment with triphenylphosphine and carbon 19 tetrabromiae, followed by metatheses of the bromopenta-decane with potassium cyanide to produce hexadecanitrile 21 11,11,12,12-d4 which in turn is hydrolyzed usin~ 20% aqueous 22 alcoholic sodium hydroxide solution to produce the desired 23 palmitic-11,11,12,12-d4 acid.
24 The novel, specifically labelled fatty acids of the present invention are valuable compounds used in many 26 kinds of specialized research work in addition to their 27 utility for the same purposes as the commercially available 28 palmitic acid. General applications include their use in 29 the study of reaction mechanisms, as tracers in the study of separation processes, and as model compounds for inves-31 tigation of the physical properties of labelled compounds.
.. .. . . . - . .. .. . .
~ 7~8~ l5996 1 They are also useful in the study of the naturally occur-2 ring unlabelled acids in biological systems, and as such 3 may be employed in the clinical diagnosis o~ conditions 4 which involve the production or abstraction of fatty acids.
They are also useful in the study of the metabolism and 6 biosynthe=i= of the corresponding unlabelled compound=.
:.
, .
~t7~b;S
; 1 EXAMPLE 1 ~ Palmitic 5,5,6,6-d~ Acid 3 Step A: 4-Chlorobutanol tetrahydropyranyl ether 4 C1~ ~
' A mixture of 4-chlorobutanol (21.7 9.) and p-6 toluenesulfonic acid (250 my.)in anhydrous ether is added 7 to dihydropyran (26 ml.) and the reaction mixture is stirred 8 at room temperature overnight. There is an initial mild g exothermic reaction. The solution is then diluted with ether (200 ml.) and washed twice with 0.1 M sodium carbonate 11 solution/ the ether layer containing the product is dried 12 with potassium carbonate and evaporated under reduced pres-13 sure, leaving a residue containing 4-chlorobutanol tetra-14 hydropyranyl ether. The residue is distilled, and the fraction at 74-76C./0.3 mm. ~g. is collected. Analytical ,, 16 data, nOm.r., m, 1.27-2.0, 8H; m, 3.22-4.12, 6H; s, 4.58, - 17 lH
18 Step B: 5-hexyn-1-ol-tetrahydropyranyl ether 1 9 I~C_C~
Under a nitrogen atmosphere, and with stirring, 21 acetylene is introduced into dry tetrahydrofuran (150 ml.l, 22 cooled, and maintained below 10C., while butyl lithium 23 (150 ml. of a 2.4 M solution in hexane~ is added dropwise. ;
~ ., .
24 After addition is complete, the mixture is matured for one 25 hour. A passage of acetylene gas through the mixture is ;
26 steadily maintained. A solution of 4-chlorobutanol tetra-. ;
~ 6~ 15996 1 hydropyranyl ether (50 g.) in dry hexamethyl phosphoric ~ -2 triamide (250 ml.) is added dropwise at such a rate that 3 the temperature did not exceed 20C. The reaction mixture 4 is stirred overnight at room temperature; ice, then water~
is added to dilute the mixture to one litre, and the mix-6 ture is extracted twice with ether. The ether solution is backwashed with water, dried with potassium carbonate, and 8 evaporated under reduced pressure to pro~uce a residue con-9 taining 5-hexyn~l-ol~tetrahydropyranyl ether. The residue is distilled, collecting the fraction at 66-69C. (0.25 mm.
11 Hg.), containing principally 5-hexyn-1-ol-tetrahydropyranyl 12 ether, b.p. 67-G8C./0.25 mm. IIg. Gas chromatographic 13 analysis demonstrates that the product contains 5% unreacted 14 starting material--4-chlorobutanol tetrahydropyranyl ether.
Step C: 5-~exadecynyl-1-ol 16 CH3~CH2)9C_C(CH2)40H
17 Under a nitrogen atmosphere, and with stirring 1~ and cooling, butyl lithium (66 ml. of a 2.4 M solution in 19 hexane) is added to a solution of S-hexyl-l-ol-tetrahydro-pyranyl ether (30 g.) in dry tetrahydrofuran (100 ml.), 21 ` at such a rate that the temperature remains below 10C.
22 The reaction mixture is stirred at 10C. for one hour, 23 then l-bromodecane (36.3 g.) in dry hexamethyl phosphonic 24 triamide (120 ml.) was added at a rate such that the tem-perature is maintained below 25C. ~he reaction is stirred 26 at room temperature overnight under an atmosphere of nitro-27 gen, then worked up by the addition of ice, then water, to 28 dilute the reaction to 700 ml., and is extracted twice with 29 ether. The combined ether extracts are washed several times with water, dried over potassium carbonate, and _g_ :
. . , : . - :
~ 7~8~ 15996 1 evaporated a-t reduced pressure. The residu~ is warmed at 2 50C. for two hours in methanol (200 ml.) containing p-3 toluenesulfonic acid (250 m~). The methanolic solution is 4 reduced to a quarter its volume, 0.1 M sodium carbonate solution (100 ml.) is added, and the mixture is extracted 6 with ether. The ether extract containing the product is 7 backwashed with 0.1 M sodium carbonate solution, then with 8 water, dried over magnesium sulfate, and evaporated under 9 reduced pressure. The low boiling material is mainly re-moved by distillation at 0.1 mm. (~ 80C.), and the residue 11 is chromatographed on silica gel, eluting with hexane, then 12 hexane containing 3% ethyl acetate, containing 10~ ethyl 13 acetate and finally 20% ethyl acetate. The purified prod-14 uct, 5-hexadecyl-1-ol, is characterized by n.m.r., CDC13 TMS, t, 3H, 0.88 ppm; m, 1.27, 16H; m, 1.6, 4H; m, 2.15, 16 4H; t, 3.63, 2H.
17 Step D: Hexadecane-5,5,6,6-d4-1-ol 18 CH3(cH2)9cD2(cH2)4 19 The hydroxyl group of 5-hexadecyl-1-ol is ex-changed by washing an ethereal solution of the compound 2] several times with excess deuterium oxide. The recovered 22 5-hexadecyn-1-ol-OD ~16 g.) is dissolved in 500 ml. of dry, 23 oxygen-free toluene; and under an atmosphere of nitrogen, 24 tris-~triphenylphosphoro~rhodium chloride (0.5 g~) is added as a catalyst. The acetylenic compound is reduced with D2 26 gas at 1 atmosphere pressure, taking up the calculated 27 volume of deuterium. The toluene solution is evaporated 28 under reduced pressure; the residue is extracted with ether ' .
' .
, , ' "' ' ' '." ' " ' ~ ' ''. ' ,' ' .~ ' , ' &~
1 several times; and combined extracts are filtered and evap-2 orated to dryness. The residue is distilled 125-128C.
3 (0.2 mm. Hg.), giving 14 g. of product.
4 Step E: Hexadecanal-5,5,6,6-d4 CH3(CH2)9CD2CD2(CH2)3CHO
6 In an appropriate flask fitted with a reflux 7 condensor is suspended 8.4 g. (86 mmole) of pyridinium 8 chlorochromate prepared as described in E. J. Corey and 9 J. William Suggs Tetrahedron Letters, p. 2647 (1975), in 100 ml. anhydrous methylene chloride. A solu-tion of 11 hexadecane-5,5,6,6-d4-1-ol (14 g., 57 mmole) in 20 ml.
12 methylene chloride is added in one portion to the stirred 13 solution. After 1.5 hours~ 100 ml. of dry ether is added 14 and the supernatant decanted from the black gum, which separates from the reaction mixture. The insoluble resi-16 due is then washed thoroughly three times with 50 ml.
17 portions of anhydrous ether; whereupon the insoluble black 18 gum residue becomes a black granular solid. The decanted 19 supernatant solution is combined with the ether extracts ;, .
containing the product and passed through a filter pad;
21 and the solvent is removed by distillation under reduced 22 pressure, leaving the product as a residual oil. The 23 product is purified by distillation at 115-120C. (0.15 24 mm.), thereby providing substantially pure hexadecanal-
5,5,6,6-d4, b.p. 115-120C./0.15 mm. Hg. The undistilled 26 residue comprising principally palmitoyl 5,5,6,6-d~-palmi-27 tate 5,5,6,6-d4 is recycled by reduction of the ester with 28 lithium aluminum hydride in ether to the starting material, 29 hexadecanol-5,5,6,6-d4.
.. . ... . . .
. ' , ' , ' ' :
- l:)Y~
1 Step F: Palmitic-5,5,6,6-d Acid 2 CII3 (CH2) gCD2CD2 (CH2) 3COOH
3 To a stirred, cooled suspension of hexadecanal 4 5,5,6,6-d4 (7.5 g.) in 100 ml. of acetic acid is added, dropwise, chromic acid l4.7 g.) in water (10 ml.) over a
.. . ... . . .
. ' , ' , ' ' :
- l:)Y~
1 Step F: Palmitic-5,5,6,6-d Acid 2 CII3 (CH2) gCD2CD2 (CH2) 3COOH
3 To a stirred, cooled suspension of hexadecanal 4 5,5,6,6-d4 (7.5 g.) in 100 ml. of acetic acid is added, dropwise, chromic acid l4.7 g.) in water (10 ml.) over a
6. period of 45 minutes. The temperature is maintained below
7 55C. The reaction is stirred for a further hour, diluted
8 with H2O to 500 ml., and extracted with ether (3 X 150 ml.)O
9 The combined ether extracts are washed with H2O (5 X 200 ml.), dried over magnesium sulfate, and evaporated. Resid-11 ual acetic acid is removed by distillation with toluene.
12 The crude acid is purified by distillation 154-157C.
13 (0.15 mm.) and crystallization from petroleum ether (30-14 60C.) at low temperature to a~ford substantially pure palmitic-5,5,6,6-d4 acid, m.p. 63C (lit 63C. of the 16 corresponding light palmitlc acid). Mass spectrum 17 M+ = 260 (d4) = 96.95%, 259 (d3) = 3.05~; (98-98 atom ~O).
19 Palmitic 7,7,8,8-d4 Acid ;
20- Step A: 7-~exadecynoic Acid .
21 CH3(CH2)7C-C(CH2)5COOH
22 A solution of l-decyne (14 g.) in dry tetrahydro-23 furan (40 ml.) is cooled in an atmosp~ere of nitrogen to 24 < 0C. Butyllithium (45 ml. of 2.4 M solution) in hexane is added at such a rate that the internal reaction tempera-26 ture does not exceed 10C. When addition is complete, the ., . , .
- . . , : : . : ,., .. . . : ..
~ 7~ 15996 .
1 solution of l-lithiodecyne is matured for one hour at 5-- 2 10C.; and the 6-bromo-hexanoic acid in 40 ml. o~ dry hexa-; 3 methyl phosphonic triamide is added at a rate such that 4 the reaction does not go above 25C. After addition is complete, the reaction is stirred at room temperature over-6 night. The reaction mixture i5 diluted with iee and water, I acidified to pH 2, and extracted with ether. The combined 8 ether extracts are backwashed with H20, dried over magnesium 9 sulfate, and evaporated under reduced pressure. The residue containin~ the product is distilled. The Pirst ~raction 11 is reasonably pure, unreacted l-decyne (,-8 ~.), then the 12 temperature rises over a few minutes to 155C. at 0.1 mm.
13 The product is then recovered substantially pure as an oil.
14 Step B: Palmitic-7,7,8,8-d4 Acid , CII3(C~I2)7CD2CD2~CH2)5CH
:.- .
16 The 7-hexadecynoic acid is converted to the methyl 17 ester with methanol and hydrogen chloride. The ester is 18 reduced in a manner analogous to the reduction of 5-hexa-., ~ .
' 19 decyn-ol as described in Example 1, Step D. The reeovered methyl palmitate 7,7,8,8-d4 is converted to the acid by 21 hydrolysis with sodium hydroxide in aqueous methanol. The 22 acid is erystallized from petroleum ether at low tempera-23 ture; m.p. 63-63C.
:
~ 25 Palmitic 16,16,16-d3 Acid .` ' - 26 Step A: 10-Undeeyn-l-ol tetrahydropyranyl ether 27 HC-C(CII2)90THP
28 10-undecynoic aeid is reduced with lithium , :, - , . ~
-- ~ 15996 38~
1 aluminum hydride in ether, by standard procedures, to the 2 10-undecyn-1-ol. The 10-undecyn-1-ol is converted to its 3 tetrahydropyranyl ether by a method analo~ous to that des-4 cribed above from 4-chlorobutanol (Example 1, Step A).
Step B: l-bromopentane 5,5,5-d3 6 CD3(CH2)~Br 7 Ethyl-2,2,2-d3 bromide (45 g.) is added dropwise ~ to a cooled, stirred suspension of Mg. (9.35 g.) in 200 ml.
9 of anhydrous ether. After the Griqnard reagent has formed, trimethylene oxide (27 g.) in anhydrous ether ~60 ml.) i5 11 added over 2-3 minutes. The reaction mixture is refluxed 12 for one hour, then dry benzene is added slowly while the 13 ether is distilled out. After all ether has been replaced 14 with benzene, the reaction is refluxed for a further 3 hours. Saturated ammonium chloride solution is then added 16 slowly to the cooled reaction mixture. The mixture, after 17 acidification with hydrochloric acid solution, is extracted 18 with ether (4 X 100 ml.); the combined extracts are dried 19 over magnesium sulfate and evaporated under reduced pres-sure until most of the ether is removed. The residue is 21 distilled through a vigreUx column, and two major ractions 22 are collected. The first at ~ 60C., thP second at 134-23 140C. The second fraction is crude l-pentanol (14 24 A mixture of the above product, triphenylphos-phene (45.2 g.), and dimethylformamide is treated with 26 bromine until the orange colour persists. The reaction 27 is stirred for a further hour, and the volatile material, 28 including dimethyl formamide, is removed under reduced - ' .
- '.
~7~
1 pressure. To the distillate is added H20 (oOO ml.). The 2 lower layer is carefully separated, backwashed twice with 3 water, dried over magnesium sulfate, and ~iltered. The 4 ma~nesium sulfate is extracted twice with ether, and the combined washings and product layer are combined and dis-6 tilled. Pure l-bromopentane 5,5,5-d3 is obtained. Single 7 peak by g.c.
8 Step C: 10-Hexadecyn-16,16,16-d301 9 CD3(CF12)4CgC(CH2)9-OH
Using 10-undecyn-1-ol tetrahydropyranyl ether 11 (34~5 g.) and l-bromopentane 5,5,5-d3 (35 g.), 10-hexa-12 decyn-1-ol-16,16,16-d3 is prepared in a manner analogous 13 to that described for 5-hexadecyn-1-ol (Example 1, Step C).
14 The product is partially separated from the major impurity
12 The crude acid is purified by distillation 154-157C.
13 (0.15 mm.) and crystallization from petroleum ether (30-14 60C.) at low temperature to a~ford substantially pure palmitic-5,5,6,6-d4 acid, m.p. 63C (lit 63C. of the 16 corresponding light palmitlc acid). Mass spectrum 17 M+ = 260 (d4) = 96.95%, 259 (d3) = 3.05~; (98-98 atom ~O).
19 Palmitic 7,7,8,8-d4 Acid ;
20- Step A: 7-~exadecynoic Acid .
21 CH3(CH2)7C-C(CH2)5COOH
22 A solution of l-decyne (14 g.) in dry tetrahydro-23 furan (40 ml.) is cooled in an atmosp~ere of nitrogen to 24 < 0C. Butyllithium (45 ml. of 2.4 M solution) in hexane is added at such a rate that the internal reaction tempera-26 ture does not exceed 10C. When addition is complete, the ., . , .
- . . , : : . : ,., .. . . : ..
~ 7~ 15996 .
1 solution of l-lithiodecyne is matured for one hour at 5-- 2 10C.; and the 6-bromo-hexanoic acid in 40 ml. o~ dry hexa-; 3 methyl phosphonic triamide is added at a rate such that 4 the reaction does not go above 25C. After addition is complete, the reaction is stirred at room temperature over-6 night. The reaction mixture i5 diluted with iee and water, I acidified to pH 2, and extracted with ether. The combined 8 ether extracts are backwashed with H20, dried over magnesium 9 sulfate, and evaporated under reduced pressure. The residue containin~ the product is distilled. The Pirst ~raction 11 is reasonably pure, unreacted l-decyne (,-8 ~.), then the 12 temperature rises over a few minutes to 155C. at 0.1 mm.
13 The product is then recovered substantially pure as an oil.
14 Step B: Palmitic-7,7,8,8-d4 Acid , CII3(C~I2)7CD2CD2~CH2)5CH
:.- .
16 The 7-hexadecynoic acid is converted to the methyl 17 ester with methanol and hydrogen chloride. The ester is 18 reduced in a manner analogous to the reduction of 5-hexa-., ~ .
' 19 decyn-ol as described in Example 1, Step D. The reeovered methyl palmitate 7,7,8,8-d4 is converted to the acid by 21 hydrolysis with sodium hydroxide in aqueous methanol. The 22 acid is erystallized from petroleum ether at low tempera-23 ture; m.p. 63-63C.
:
~ 25 Palmitic 16,16,16-d3 Acid .` ' - 26 Step A: 10-Undeeyn-l-ol tetrahydropyranyl ether 27 HC-C(CII2)90THP
28 10-undecynoic aeid is reduced with lithium , :, - , . ~
-- ~ 15996 38~
1 aluminum hydride in ether, by standard procedures, to the 2 10-undecyn-1-ol. The 10-undecyn-1-ol is converted to its 3 tetrahydropyranyl ether by a method analo~ous to that des-4 cribed above from 4-chlorobutanol (Example 1, Step A).
Step B: l-bromopentane 5,5,5-d3 6 CD3(CH2)~Br 7 Ethyl-2,2,2-d3 bromide (45 g.) is added dropwise ~ to a cooled, stirred suspension of Mg. (9.35 g.) in 200 ml.
9 of anhydrous ether. After the Griqnard reagent has formed, trimethylene oxide (27 g.) in anhydrous ether ~60 ml.) i5 11 added over 2-3 minutes. The reaction mixture is refluxed 12 for one hour, then dry benzene is added slowly while the 13 ether is distilled out. After all ether has been replaced 14 with benzene, the reaction is refluxed for a further 3 hours. Saturated ammonium chloride solution is then added 16 slowly to the cooled reaction mixture. The mixture, after 17 acidification with hydrochloric acid solution, is extracted 18 with ether (4 X 100 ml.); the combined extracts are dried 19 over magnesium sulfate and evaporated under reduced pres-sure until most of the ether is removed. The residue is 21 distilled through a vigreUx column, and two major ractions 22 are collected. The first at ~ 60C., thP second at 134-23 140C. The second fraction is crude l-pentanol (14 24 A mixture of the above product, triphenylphos-phene (45.2 g.), and dimethylformamide is treated with 26 bromine until the orange colour persists. The reaction 27 is stirred for a further hour, and the volatile material, 28 including dimethyl formamide, is removed under reduced - ' .
- '.
~7~
1 pressure. To the distillate is added H20 (oOO ml.). The 2 lower layer is carefully separated, backwashed twice with 3 water, dried over magnesium sulfate, and ~iltered. The 4 ma~nesium sulfate is extracted twice with ether, and the combined washings and product layer are combined and dis-6 tilled. Pure l-bromopentane 5,5,5-d3 is obtained. Single 7 peak by g.c.
8 Step C: 10-Hexadecyn-16,16,16-d301 9 CD3(CF12)4CgC(CH2)9-OH
Using 10-undecyn-1-ol tetrahydropyranyl ether 11 (34~5 g.) and l-bromopentane 5,5,5-d3 (35 g.), 10-hexa-12 decyn-1-ol-16,16,16-d3 is prepared in a manner analogous 13 to that described for 5-hexadecyn-1-ol (Example 1, Step C).
14 The product is partially separated from the major impurity
10-undecyn-1-ol by column chromatography and used in the 16 next step without further purification.
17 Step D: Hexadecan-l-ol 16,16,16-d3 18 CD3(CH2)14CH2OH
19 The crude 10-hexadecyn-1-ol 16,16,16-d3 obtained above is reduced with H2 in the presence of tris-(triphenyl-21 phosphoro)-rhodium chloride as described for 5-hexadecyn-22 l-ol. The crude recovered product is carefully distilled, 23 givin~ pure hexadecan-l-ol 16,16,16-d3; b.p. 115-118C./
24 0.15 mm. Hg.
,'` .
" 15996 7~
1 Step E:Palmitic 16,16,16~d3 Acid 2 CD3(CH2)14COO~
;' 3 The hexadecan-l-ol 16,16,16-d3 is oxidized in 4 two steps using pyridinium chlorochromate then chromic acid in acetic acid as described for hexadecan-1-ol 5,5, 6- 6,6-d~ (Example 1, Steps E and F), to ~ive, after the same 7purification procedure, palmitic 16,16,16-d3 acid; m.p., 10Palmitic 11,11,12,12-d4 Acid __ _
17 Step D: Hexadecan-l-ol 16,16,16-d3 18 CD3(CH2)14CH2OH
19 The crude 10-hexadecyn-1-ol 16,16,16-d3 obtained above is reduced with H2 in the presence of tris-(triphenyl-21 phosphoro)-rhodium chloride as described for 5-hexadecyn-22 l-ol. The crude recovered product is carefully distilled, 23 givin~ pure hexadecan-l-ol 16,16,16-d3; b.p. 115-118C./
24 0.15 mm. Hg.
,'` .
" 15996 7~
1 Step E:Palmitic 16,16,16~d3 Acid 2 CD3(CH2)14COO~
;' 3 The hexadecan-l-ol 16,16,16-d3 is oxidized in 4 two steps using pyridinium chlorochromate then chromic acid in acetic acid as described for hexadecan-1-ol 5,5, 6- 6,6-d~ (Example 1, Steps E and F), to ~ive, after the same 7purification procedure, palmitic 16,16,16-d3 acid; m.p., 10Palmitic 11,11,12,12-d4 Acid __ _
11 Step A:Pentadecan-l-ol 10,10,11,11-d4
12 CH3(CE~2)3CD2cD2(cH2)9
13 Pentadecan-l-ol 10,10,11,11-d4 is prepared in 14an exactly analogous manner to hexadecan-l-ol 16,16,16-d3 (described in Example 3), except l-bromobutane is used in 16 place of l-bromopentane 5,5,5-d3 and deuterium is used in 17 place of hydro~en in the reduction step.
, 18 Step B:l-Bromopentadecane 10,10,11,11-d4 .
19 CH3(CH2)3CD2cD2(cH2)9 Triphenylphosphine (11.3 q.) is added to a mix-21ture of ether (80 ml.), carbon tetrabromide (14.3 ~.), and 22pentadecan-l-ol 10,10,11,11-d4; and the reaction mixture 23 is then refluxed. The progress of the reaction is moni-2~ tored by gas chromatoqraphic analysis of aliquots taken from the reaction mixture. After five hours, the reaction '~ .
. ' ' :
. .
~ I( sr;;J~ 5 1 is complete. Solvent is removed under reduced pressure, 2 and the residue filtered through a column of silica ~el, 3 eluting with hexane. The product is collected and distilled 4 to ~ive substantially pure l-bromopentadecane 10,10,11,11-d4 (~ 130C./0.2 mm. Hg.).
6 Step C: Hexadecanitrile 11,11,12,12-d4 7 CH3(CH2)3CD2cD2(cH2)9c 8 A mixture of 1-bromopentadecane 10,10,11,11-d4 9 (5.9 g.), potassium cyanide (2.6 g.), and ethanol (60 ml.) are re~luxed. The reaction is monitored by t.l.c. (thin 11 layer chromatography). After refluxin~ overni~ht, the 12 reaction is complete. The reaction is cooled, evaporated 13 to a small volume, diluted with ether, and washed with
, 18 Step B:l-Bromopentadecane 10,10,11,11-d4 .
19 CH3(CH2)3CD2cD2(cH2)9 Triphenylphosphine (11.3 q.) is added to a mix-21ture of ether (80 ml.), carbon tetrabromide (14.3 ~.), and 22pentadecan-l-ol 10,10,11,11-d4; and the reaction mixture 23 is then refluxed. The progress of the reaction is moni-2~ tored by gas chromatoqraphic analysis of aliquots taken from the reaction mixture. After five hours, the reaction '~ .
. ' ' :
. .
~ I( sr;;J~ 5 1 is complete. Solvent is removed under reduced pressure, 2 and the residue filtered through a column of silica ~el, 3 eluting with hexane. The product is collected and distilled 4 to ~ive substantially pure l-bromopentadecane 10,10,11,11-d4 (~ 130C./0.2 mm. Hg.).
6 Step C: Hexadecanitrile 11,11,12,12-d4 7 CH3(CH2)3CD2cD2(cH2)9c 8 A mixture of 1-bromopentadecane 10,10,11,11-d4 9 (5.9 g.), potassium cyanide (2.6 g.), and ethanol (60 ml.) are re~luxed. The reaction is monitored by t.l.c. (thin 11 layer chromatography). After refluxin~ overni~ht, the 12 reaction is complete. The reaction is cooled, evaporated 13 to a small volume, diluted with ether, and washed with
14 0.1 M sodium hydrogen carbonate solution, and extracted with ether. The ether solution is dried and evaporated, 16 leaving hexadecanitrile 11,11,12,12-d4 as a product, which 17 is identified by n.m.r. CDC13, t, 3H, 0.8~; m, 1.28, 22H;
18 t, 2H, 2.30, and i.r. EC-D, 2090 cm 1, 2190 cm 1].
19 Step D: Palmitic-11,11,12,12-d Acid 2~ C~3(cH2)3cD2cD2(cH2)gCOOH
21 Hexadecanitrile 11,11,12,12-d4 (4.8 q.) is com-22 bined with 20~ sodium hydroxide solution (20 ml.) and 23 ethanol ~100 ml.) and refluxed for 16 hours. All nitrile 24 is consumed by the procedure as demonstrated by t.l.c.
The mixture is carefully acidified with aqueous hydrochloric 26 acid. The ethanol is largely removed by evaporation at 27 reduced pressure, and the mixture is extracted with ether.
, . .
18 t, 2H, 2.30, and i.r. EC-D, 2090 cm 1, 2190 cm 1].
19 Step D: Palmitic-11,11,12,12-d Acid 2~ C~3(cH2)3cD2cD2(cH2)gCOOH
21 Hexadecanitrile 11,11,12,12-d4 (4.8 q.) is com-22 bined with 20~ sodium hydroxide solution (20 ml.) and 23 ethanol ~100 ml.) and refluxed for 16 hours. All nitrile 24 is consumed by the procedure as demonstrated by t.l.c.
The mixture is carefully acidified with aqueous hydrochloric 26 acid. The ethanol is largely removed by evaporation at 27 reduced pressure, and the mixture is extracted with ether.
, . .
15~96 .
1 The ether solution is washed once with water, dried over 2 magnesium sulfate, and evaporated. The acid product is 3 crystallized at low temperature from petroleum ether (30-4 60C.), m.p. 62-63C.
'~' : .
~.
~; , .
, .. .
. . .
' . .. ' . . ' : : . .' . : . .
: . ' - . :. . :, , ~ : , :- : . .
1 The ether solution is washed once with water, dried over 2 magnesium sulfate, and evaporated. The acid product is 3 crystallized at low temperature from petroleum ether (30-4 60C.), m.p. 62-63C.
'~' : .
~.
~; , .
, .. .
. . .
' . .. ' . . ' : : . .' . : . .
: . ' - . :. . :, , ~ : , :- : . .
Claims (15)
1. A process for the preparation of specifically labelled fatty acids which comprises the steps of alkyl-ating a terminal acetylene substituent in an aliphatic compound having a carboxyl substituent or a functional substituent convertible to carboxyl and subsequently hydrog-enating or deuterogenating said acetylenic substituent to produce a specifically labelled fatty acid or compound readily convertible thereto.
2. A process according to Claim 1 which com-prises conducting the hydrogenation or deuterogenation reaction in the presence of a catalyst which is soluble in the reaction mixture.
3. A process according to Claim 2 wherein the catalyst is tris-(triphenylphosphoro)rhodium chloride.
4. A process according to Claim 1 which com-prises the steps of alkylating a terminal acetylene sub-stituent in an alkynoic acid and subsequently deuterog-enating said acetylenic substituent to produce a tetra-deuterated aliphatic carboxylic acid.
5. A process according to Claim 1 which com-prises the steps of alkylating the terminal acetylene sub-stituent in an alkyn-1-ol, subsequently deuterogenating said alkylated alkyn-1-ol, to produce the corresponding tetradeuterated alkan-1-ol and converting said alkanol by known means to the corresponding tetradeuterated aliphatic carboxylic acid.
6. A process according to Claim 1 which com-prises the steps of alkylating a terminal acetylene sub-stituent in an alkyn-1-ol by treatment with a deuteroalkyl halide in the presence of butyl lithium to produce a deuteroalkylalkyn-1-ol, subsequently hydrogenating said deuteroalkylalkyn-1-ol to produce the corresponding deutero-alkanol and converting said alkanol by known means to a specifically deuterated aliphatic carboxylic acid.
7. A process according to Claim 1 which com-prises contacting 5-hexyn-1-ol-tetrahydropyranyl ether with 1-bromodecane in the presence of butyl lithium to produce 5-hexadecyn-1-ol and subsequently contacting said hexadecynol with deuterium gas in the presence of tris-(triphenylphosphoro)rhodium chloride to produce hexadecane 5,5,6,6-d4-1-ol and subsequently converting said hexa-decanol by known means to palmitic-5,5,6,6-d4 acid.
8. A process according to Claim 1 which com-prises contacting 1-decyne with 6-bromohexanoic acid in the presence of butyl lithium to produce 7-hexadecynoic acid and subsequently contacting said hexadecynoic acid with deuterium in the presence of tris-(triphenylphos-phoro)rhodium chloride to produce palmitic-7,7,8,8-d4 acid.
9. A process according to Claim 1 which com-prises contacting 10-undecynol tetrahydropyranyl ether with 1-bromopentane-5,5,5-d3 in the presence of butyl lithium to produce 10-hexadecyn-1-ol 16,16,16-d3 and subsequently contacting said hexadecynol with hydrogen in the presence of tris-(triphenylphosphoro)rhodium chloride to produce hexadecan-1-ol-16,16,16-d3 and converting said hexadecanol by known means to palmitic-16,16,16-d3 acid.
10. A process according to Claim 1 which com-prises contacting 10-undecyn-1-ol with 1-bromobutane in the presence of butyl lithium to produce 10-pentadecyn-1-ol and subsequently contacting said pentadecyn-1-ol with deuterium gas in the presence of tris-(triphenylphosphoro)-rhodium chloride to produce pentadecan-1-ol 10,10,11,11-d4, converting said pentadecanol by bromination to the corres-ponding 1-bromopentadecane 10,10,11,11-d4, contacting said bromopentadecane with potassium cyanide to produce hexa-decanitrile 11,11,12,12-d4, and hydrolyzing said nitrile to produce palmitic-11,11,12,12-d4 acid.
11. A specifically deuterated fatty acid com-pound selected from palmitic 5,5,6,6-d4 acid, palmitic 7,7,8,8-d4 acid, palmitic 16,16,16-d3 acid, and palmitic 11,11,12,12-d4 acid.
12. Palmitic 5,5,6,6-d4 acid.
13. Palmitic 7,7,8,8-d4 acid.
14. Palmitic 16,16,16-d3 acid.
15. Palmitic 11,11,12,12-d4 acid.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA282,165A CA1078865A (en) | 1977-07-06 | 1977-07-06 | Isotopically labelled fatty acids |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA282,165A CA1078865A (en) | 1977-07-06 | 1977-07-06 | Isotopically labelled fatty acids |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1078865A true CA1078865A (en) | 1980-06-03 |
Family
ID=4109076
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA282,165A Expired CA1078865A (en) | 1977-07-06 | 1977-07-06 | Isotopically labelled fatty acids |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1078865A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1985004167A1 (en) * | 1984-03-19 | 1985-09-26 | The Commonwealth Of Australia | Labelling of organic molecules |
| WO2001051094A1 (en) * | 2000-01-13 | 2001-07-19 | Lightouch Medical, Inc. | Diagnostic method using a deuterated agent for imaging specific tissue |
| US20150072366A1 (en) * | 2012-09-20 | 2015-03-12 | Nicolaas E. Deutz | Methods for Measuring Fat Digestibility and Uses Thereof |
| CN111196756A (en) * | 2020-02-24 | 2020-05-26 | 南京昊绿生物科技有限公司 | Synthesis method of caproic acid-D7 |
-
1977
- 1977-07-06 CA CA282,165A patent/CA1078865A/en not_active Expired
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1985004167A1 (en) * | 1984-03-19 | 1985-09-26 | The Commonwealth Of Australia | Labelling of organic molecules |
| US6503478B2 (en) | 1999-01-13 | 2003-01-07 | Lightouch Medical, Inc. | Chemically specific imaging of tissue |
| WO2001051094A1 (en) * | 2000-01-13 | 2001-07-19 | Lightouch Medical, Inc. | Diagnostic method using a deuterated agent for imaging specific tissue |
| US20150072366A1 (en) * | 2012-09-20 | 2015-03-12 | Nicolaas E. Deutz | Methods for Measuring Fat Digestibility and Uses Thereof |
| US10175245B2 (en) * | 2012-09-20 | 2019-01-08 | Nicolaas E. Deutz | Methods for measuring fat digestibility and uses thereof |
| CN111196756A (en) * | 2020-02-24 | 2020-05-26 | 南京昊绿生物科技有限公司 | Synthesis method of caproic acid-D7 |
| CN111196756B (en) * | 2020-02-24 | 2022-04-08 | 南京昊绿生物科技有限公司 | Synthesis method of caproic acid-D7 |
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