SYNTHESIS OF CERTAIN HIGHER ALIPHATIC COMPOUNDS. PART I. 175 XXVIL-Synthesis of certain Higher Aliphatic Cmn-pounds. Part I . A S'ynthesis of Lactarinic Acid and of Oleic Acid. By GERTRUDE MAUD ROBINSON and ROBERT ROBIK'SON. THIS investigation originated in a desire to develop methods which could be applied to the synthesis of the naturally occurring unsatur-ated fatty acids and attention was concentrated in the first place on attempts to synthesise oleic acid. An examination of the literature shows that this acid has been obtained from 10-ketostearic acid,* CH,*[CH,],*CO*[CH,],*CO,H by reduction to hydroxystearic acid followed by conversion to iodostearic acid and treatment with alcoholic potassium hydroxide (see p. 179). It therefore became an object to devise a process for the preparation of acids of the form R*[CH,],*CO*[CH,],*CO,H which should be applicable t o a case such that R*[CH,],I cannot be readily converted into an organo-zinc or magnesium derivative.After numerous trials in other directions, it was found that ethyl sodio-n-heptylmalonate and 9-carbethoxy-nonoyl chloride condensed in ethereal solution to a product which * Tho carboxyl group of stearic acid is numbered 1 in this communication This syste:n in order to avoid confusion with the Geneva nomenclature. has been frequently adopted in recent literature 156 ROBINSON AND ROBINSON SYNTHESIS OF gave a very small yield of 10-ketostearic acid on prolonged hydrolysis with boiling 1 yo aqueous oxalic acid. A considerable improvement was effected by starting with ethyl acetoacetate instead of ethyl malonate.Ethyl sodio-2-acetylnonoate and 9-carbethoxynonoyl chloride were brought into reaction in ether and the resulting ester, CH,*[CH,],*CAc( CO,Et)*CO*[ CH,] ,*CO,Et was cautiously hydro-lysed at first by cold dilute alkali then by boiling dilute sulphuric acid and finally by boiling dilute aqueous sodium hydroxide. The aparingly soluble crystalline sodium salt of 10-ketostearic acid separated on cooling the solution. This acid melts at 83" and the product of the action of sulphuric acid and water on stearolic acid, after a wasteful process of purification melts at the same temper-ature alone or mixed with the synthetic specimen. It is probable that the isomeride accompanying 10-ketostearic acid in the crude material derived from stearolic acid is 9-ketostearic acid and we are engaged in the preparation of this substance in order to determine the proportions in which the acetylenic bond is hydrated in the two possible directions.The synthesis of oleic acid by way of 10-keto-stearic acid and 10-iodostearic acid affords a proof that the double bond is in the position A9:10 or AIO'I1 and in order to eliminate the latter alternative we are engaged in an attempt to synthesise stearolic acid. We have found that this acid may be reduced to oleic acid by means of zinc dust and hydrochloric acid in presence of titanous chloride in acetic acid solution. Elaidic and stearic acids are not produced under the conditions described (p. 177) and the reaction indicates that oleic acid has the cis-configuration.The addition of hydrogen iodide to stearolic acid has been previously shown to lead to isomeric iodoelaidic acids which can be transformed into elaidic acid (Arnaud and Posternak C m p t . rend. 1910 150 1130, 1525). In the course of investigations on the constituents of certain fungi, Bougault and Charaux found that several species of Lactarius contained a ketostearic acid termed lactarinic acid in the free state (Compt. rend. 1911 153 572 880). The results obtained by applying the Beckmann transformation to the oxime of lactarinic acid showed that the substance must be 6-ketostlearic acid and we have now confirmed this conclusion by synthesis. Ethyl sodio-2-acetyl-n-tridecoate and 5-carbethoxyvaleryl chloride react in ethereal solution so as to produce the ester CH,*[CH2],,~CAc(C0,Et)~CO*[CH2],*C0,Et, which by graduated hydrolysis yields lactarinic acid, CH,*[CH,]ll-CO*[CH,]4*C02H.We are greatly indebted to &ofessor Bougault for a specimen of the acid of natural origin and a careful comparison proved the identit CERTAIN HIGHER ALIPHATIC COMPOUNDS. PART I. 177 of this with the synthetical product. At the suggestion of Professor H. S. Raper we have also synthesised 4-ketopalmitic acid in order to render possible a direct comparison with a substance prepared by the oxidation of palmitic acid. I n this case ethyl sodio-2-acetyl-n-tridecoate and 3-carbomethoxypropionyl chloride gave the ester CH,-[CH,]1,*CAc(C02Et)CO*[CH,]2*C0,Me and by hydrolysis the desired keto-acid CH,*[CH,],,*CO*[CH,]~*CO,H.E x P E R I M E N T A L . Reduction of Xtearolic Acid to Oleic Acid .-Hydrochloric acid (50 C.C. of 40%) was slowly added to a gently boiling mixture of acetic acid (30 g.) aqueous titanous chloride (10 g. of 15%) stearolic acid (3 g.) and zinc dust (10 g.) contained in a flask closed by a tube bearing a Bunsen valve. After 2 hours zinc dust (5 g.) and acetic acid (20 c.c.) were added and the process was completed by boiling for 2 hours. The product was mixed with ether the separated ethereal solution well washed with water and the acid contained converted into its barium salt (3.5 g.) which was twice crystallised from a mixture of benzene (8 vols.) ethyl alcohol (1 vol.) and a trace of water. The free oleic acid obtained from the barium salt and hot dilute hydrochloric acid was dried in light petroleum (b.p. 4 0 4 5 " ) with anhydrous sodium sulphate and the solvent removed. The residue consisting of the pure acid crystallised on cooling as a glassy mass which froze at 12-5" in one experiment and at 13" in another. These freezing points were taken with the thermometer immersed in the liquid and the specimen freezing a t 13" froze a t the same temperature when mixed with a specimen of pure oleic acid prepared from olive oil for which me are indebted to Professor A. Lapworth. The characteristic dimorphism exhibited by oleie acid has been described by Iiirchner (2. physikaE. Chem., 1913 79 789) and when the acid freezing at 13" was maintained a t about 12" the nuclei of the new modification gradually formed and closely resembled in appearance under the lens the photographs reproduced in the memoir quoted above.The transformed material melted just above 16". When the acid dissolved in 300 times its weight of water and one-third of its weight of potassium hydroxide was oxidised at 0" by the gradual addition of 0.5h7-potassium permanganate dihydroxystearic acid was produced in almost theoretical amount; it was best isolated by filtration after the passage of sulphur dioxide. The substance crystallised from alcohol-benzene melted at 132" alone or mixed with a specimen prepared from oleic acid from olive oil. The melting point 136" given in the literature for this acid is too high. 9-C'arEethoxynona?tilide.-Ethyl hydrogen sebacate (22 g . ) (Grii 178 ROBINSON AND ROBINSON SYNTHESIS OF and Whfh Bey.1922 55 2207) was heated on the steam-bath for 3 hours with thionyl chloride * (66 g.) the thionyl chloride removed completely by distillation under reduced pressure and exposure of the residue to a vacuum and 9-carbethoxynonoyl chloride thus obtained in good yield treated wit'h an excess of aniline. The aizilide crystallised from light pettroleum containing a little benzene in colourless needles m. p. 63" (Found C = 70.9; H = 8.7. C1,H,,03N requires C = 70.8; H = 8.8%). 10-Ketostearic Acid.-The condensation of ethyl sodio-n-heptj-1-malonate with 9-carbethoxynonoyl chloride was carried out like that in the case of the related derivative of acetoacetic acid. The product was an oil which on hydrolysis by alkali gave heptylmalonic and sebacic acids but no ketostearic acid.Dilute sulphuric acid gave a similar result but 1% aqueous oxalic acid caused partial hydrolysis in the desired direction and a very small yield of 10-keto-stearic acid m. p. 77" could be isolated after boiling during a week. The process was obviously unsatisfactory and was abandoned in favour of tlhe following kethod. Sodium (1.2 g.) was granulated under toluene washed with ether, suspended in ether (75 c.c.) and a solution of ethyl 2-acetylnonoate (11-5 g.) (Jourdan Annalen 1879 200 105) in ether (75 c.c.) gradually added. The clear solution of the sodio-derivative obtained by gentle heating was cooled in melting ice and treated with 9-carbethoxynonoyl chloride (12.5 g . ) in ether (20 c.c.). After 1 hour the mixture was boiled for 10 minutes cooled washed with water and the ether evaporated.The residue was shaken with 5% aqueous sodium hydroxide (200 c.c.) for 2 days and then after acidification with acetic acid collected again by means of ether, boiled during 24 hours with 6% sulphuric acid (300 c.c.) and the mixture steam-distilled ; the oil in the distillate was methyl n-octyl ketone (Jourdan Zoc. cit.). The residue in the flask was once more collected by means of ether and boiled during 1.5 hours with 5% aqueous sodium hydroxide (100 c.c.). On cooling the gelatinous precipitate first formed rapidly changed to colourless leaflets, m. p. 212". The acid obtained from this salt crystallised from alcohol and from light petroleum in colourless plates m.p. 83" and a t the same temperature when rnised with 10-ketostearic acid derived from stearolic acid as described below. The two specimens were carefully compared and no differences could be discerned. Stearolic acid was dissolved in concentrated sulphuric acid (6 parts) as recommended by Baruch (Ber. 1884 27 174) but water was not added after 12 hours the solution being filtered by glass wool chloride and 1% of sulphur. * Purified by distillation after boiling under reflux with 1% of aluminiu CERTAIN ICIGIIER ALIPHATIC COMPOUNDS. PART I. 179 and kept in an open vessel. The crust which formed at the surface was removed from time to time drained on porous porcelain, crystallised from alcohol converted into sodium salt which was also crystallised from alcohol finally the recovered acid was crystallised twice from light petroleum and twice from benzene.The product melted at 83" whereas the crude acid melts at about 72" and the highest recorded melting point is 76". 10-Hydroxystearic acid prepared in theoretical yield by the reduction of pure sodium 10-ketostearate in dry alcohol by means of sodium melts at 84.5". This acid yields 10-iodostearic acid by the action of phosphorus fri-iodide and water and Arnaud and Bosternak (Cmpt. rend., 1910,150,1525) have carefully examined the products of the action of alcoholic potassium hydroxide on this iodostearic acid a reaction first investigated by Saytzeff ( J . pr. Chem. 1887 [ii] 35,387). The former authors showed that oleic acid hydroxystearic acid arid isomeric elaidic acids can be isolated.EthyE 2 - Acetyl-n-tridecoate CH,*[CH,] ,,*CHAc*CO,Et .-12*2 Grams of an oil b. p. 185"/17 mm. were obtained according to the usual method employing sodium (1.4 g.) alcohol (17.5 g.) ethyl acetoacetate (11.8 g.) n-undecyl iodide (17 g.) ; the time of reaction was 3-5 hours (Found C = 72.1 ; H = 11.1. C,,H,,O requires 6-Ketostearic Acid (Lactnrinic Acid) .-Ethyl hydrogen adipate, prepared by a method analogous to that employed by Griin and Wirth (Zoc. cit.) in the semi-hydrolysis of diethyl sebacate was converted into the acid chloride by means of pure thionyl chloride. 5-Carbethoxyvaleryl chloride (8.5 9.) dissolved in ether (10 c.c.) was added to a solution of ethyl sodio-2-acetyl-n-tridecoate (136 g.) in ether (75 c.c.) at 0" ; after remaining 4 hour at room temperature, the mixture was boiled under reflux for 15 minutes.The washed and isolated product was shaken for 16 hours with 5% aqueous sodium hydroxide (300 c.c.) collected as in the previous example, and boiled with 5% sulphuric acid (600 c.c.) for 24 hours. Steam distillation separated some methyl n-dodecyl ketone m. p. 33-34" (Krafft Eer. 1882 15 1708) and the residue in the flask was collected and heated for 4-5 hours with boiling 5% aqueous sodium hydroxide (200 c.c.). The sodium salt (4-2 g.) which crystallised on cooling was collected and the acid isolated and crystallised from alcohol. The colourless plates melted at 87" alone or mixed with an authentic specimen of lactarinic acid (Pound C = 72.7; H = 11.3. Calc.for C1BH34:3 C = 72.5; H = 11.4%). The o x i m m. p. 59-61 crystallised from light petroleum in microscopic needles and was transformed by concentrated sulphuric acid at 100" into an amide crystallising from alcohol in colourless C == 71.8; H = 11.3%) 180 SYNTHESIS OF CERTAIN HIGHER ALIPHATIC COMPOUNDS. PART I. needles m. p. 104". These m. pt's. agree with those given by Bougault and Charaux (Zoc. cit.). 3 - Carbomethoxypropionanilide CO,Me*CH,*CH,*CO*NHPh .-Methyl hydrogen succinate being a solid m. p. 58" was used in preference to the corresponding ethyl derivative in the synthesis of 4-ketopalmitic acid. Succinic anhydride conveniently obtained by the action of thionyl chloride on the acid was converted into the semi-ester by the method of Bone Sprankling and Sudborough (J.1904 85 530). 3-Carbomethoxy~ro,/r,ionyl chloride derived from the acid by the action of thionyl chloride is a colourless liquid, b. p. 93"/18 mm. and reacts with aniline with formation of 3-carbo-methoxypropionanilide which crystallises from light petroleum-benzene as also from ether in colourless needles m. p. 97-99' (Found C = 63-8 ; H = 6.4. Calc. for C1lH,,O,N C = 63.7 ; H = 6.3%). The same substance has been prepared by the action of methyl alcohol and hydrogen chloride on succinanil (van der Meulen Rec. trav. chim. 1896 15 341 ; Eioogewerth and van Dorp, ibid. 1898,1'7,200). 4-Ketopalmitic Acid.-A solution of 3-carbomethoxypropionyl chloride (ti g.) in ether (30 c.c.) was added to the sodio-derivative from ethyl 2-acetyl-n-tridecoate (1 1 g.) and granulated sodium (0.9 g.) in ether (320 c.c.).The mixture was cooled in ice-water, kept over-night and boiled under reflux for 8 hour. The washed and isolated product was hydrolysed by shaking for 6 hours with 5% potassium hydroxide (300 c.c.) boiling for 30 hours with 5% sulphuric acid (250 c.c.) and for 3 hours with 5% potassium hydroxide. The potassium salt did not separate on cooling and, on acidification of the solution 5-1 g. of almost pure 4-ketopalmitic acid were obtained. The substance crystallises from light petroleum in colourless clusters of waxy lanceolate plates m. p. 91-92" (Found C = 71.3 ; H = 11.0. C,,H,,O requires C = 71.1 ; H = 11.1 %). The oxime is readily soluble in most organic solvents and crystallises from light petroleum in colourless needles m.p. 54". We desire to express our thanks to the Food Inves-bigation Board for grants which have eiiabled one of us to take part in this investigation. TIIE UNIVERSITY MANCHESTER. [Received November loth 1924. SYNTHESIS OF CERTAIN HIGHER ALIPHATIC COMPOUNDS. PART I. 175 XXVIL-Synthesis of certain Higher Aliphatic Cmn-pounds. Part I . A S'ynthesis of Lactarinic Acid and of Oleic Acid. By GERTRUDE MAUD ROBINSON and ROBERT ROBIK'SON. THIS investigation originated in a desire to develop methods which could be applied to the synthesis of the naturally occurring unsatur-ated fatty acids and attention was concentrated in the first place on attempts to synthesise oleic acid. An examination of the literature shows that this acid has been obtained from 10-ketostearic acid,* CH,*[CH,],*CO*[CH,],*CO,H by reduction to hydroxystearic acid followed by conversion to iodostearic acid and treatment with alcoholic potassium hydroxide (see p.179). It therefore became an object to devise a process for the preparation of acids of the form R*[CH,],*CO*[CH,],*CO,H which should be applicable t o a case such that R*[CH,],I cannot be readily converted into an organo-zinc or magnesium derivative. After numerous trials in other directions, it was found that ethyl sodio-n-heptylmalonate and 9-carbethoxy-nonoyl chloride condensed in ethereal solution to a product which * Tho carboxyl group of stearic acid is numbered 1 in this communication This syste:n in order to avoid confusion with the Geneva nomenclature.has been frequently adopted in recent literature 156 ROBINSON AND ROBINSON SYNTHESIS OF gave a very small yield of 10-ketostearic acid on prolonged hydrolysis with boiling 1 yo aqueous oxalic acid. A considerable improvement was effected by starting with ethyl acetoacetate instead of ethyl malonate. Ethyl sodio-2-acetylnonoate and 9-carbethoxynonoyl chloride were brought into reaction in ether and the resulting ester, CH,*[CH,],*CAc( CO,Et)*CO*[ CH,] ,*CO,Et was cautiously hydro-lysed at first by cold dilute alkali then by boiling dilute sulphuric acid and finally by boiling dilute aqueous sodium hydroxide. The aparingly soluble crystalline sodium salt of 10-ketostearic acid separated on cooling the solution. This acid melts at 83" and the product of the action of sulphuric acid and water on stearolic acid, after a wasteful process of purification melts at the same temper-ature alone or mixed with the synthetic specimen.It is probable that the isomeride accompanying 10-ketostearic acid in the crude material derived from stearolic acid is 9-ketostearic acid and we are engaged in the preparation of this substance in order to determine the proportions in which the acetylenic bond is hydrated in the two possible directions. The synthesis of oleic acid by way of 10-keto-stearic acid and 10-iodostearic acid affords a proof that the double bond is in the position A9:10 or AIO'I1 and in order to eliminate the latter alternative we are engaged in an attempt to synthesise stearolic acid. We have found that this acid may be reduced to oleic acid by means of zinc dust and hydrochloric acid in presence of titanous chloride in acetic acid solution.Elaidic and stearic acids are not produced under the conditions described (p. 177) and the reaction indicates that oleic acid has the cis-configuration. The addition of hydrogen iodide to stearolic acid has been previously shown to lead to isomeric iodoelaidic acids which can be transformed into elaidic acid (Arnaud and Posternak C m p t . rend. 1910 150 1130, 1525). In the course of investigations on the constituents of certain fungi, Bougault and Charaux found that several species of Lactarius contained a ketostearic acid termed lactarinic acid in the free state (Compt. rend. 1911 153 572 880). The results obtained by applying the Beckmann transformation to the oxime of lactarinic acid showed that the substance must be 6-ketostlearic acid and we have now confirmed this conclusion by synthesis.Ethyl sodio-2-acetyl-n-tridecoate and 5-carbethoxyvaleryl chloride react in ethereal solution so as to produce the ester CH,*[CH2],,~CAc(C0,Et)~CO*[CH2],*C0,Et, which by graduated hydrolysis yields lactarinic acid, CH,*[CH,]ll-CO*[CH,]4*C02H. We are greatly indebted to &ofessor Bougault for a specimen of the acid of natural origin and a careful comparison proved the identit CERTAIN HIGHER ALIPHATIC COMPOUNDS. PART I. 177 of this with the synthetical product. At the suggestion of Professor H. S. Raper we have also synthesised 4-ketopalmitic acid in order to render possible a direct comparison with a substance prepared by the oxidation of palmitic acid.I n this case ethyl sodio-2-acetyl-n-tridecoate and 3-carbomethoxypropionyl chloride gave the ester CH,-[CH,]1,*CAc(C02Et)CO*[CH,]2*C0,Me and by hydrolysis the desired keto-acid CH,*[CH,],,*CO*[CH,]~*CO,H. E x P E R I M E N T A L . Reduction of Xtearolic Acid to Oleic Acid .-Hydrochloric acid (50 C.C. of 40%) was slowly added to a gently boiling mixture of acetic acid (30 g.) aqueous titanous chloride (10 g. of 15%) stearolic acid (3 g.) and zinc dust (10 g.) contained in a flask closed by a tube bearing a Bunsen valve. After 2 hours zinc dust (5 g.) and acetic acid (20 c.c.) were added and the process was completed by boiling for 2 hours. The product was mixed with ether the separated ethereal solution well washed with water and the acid contained converted into its barium salt (3.5 g.) which was twice crystallised from a mixture of benzene (8 vols.) ethyl alcohol (1 vol.) and a trace of water.The free oleic acid obtained from the barium salt and hot dilute hydrochloric acid was dried in light petroleum (b. p. 4 0 4 5 " ) with anhydrous sodium sulphate and the solvent removed. The residue consisting of the pure acid crystallised on cooling as a glassy mass which froze at 12-5" in one experiment and at 13" in another. These freezing points were taken with the thermometer immersed in the liquid and the specimen freezing a t 13" froze a t the same temperature when mixed with a specimen of pure oleic acid prepared from olive oil for which me are indebted to Professor A.Lapworth. The characteristic dimorphism exhibited by oleie acid has been described by Iiirchner (2. physikaE. Chem., 1913 79 789) and when the acid freezing at 13" was maintained a t about 12" the nuclei of the new modification gradually formed and closely resembled in appearance under the lens the photographs reproduced in the memoir quoted above. The transformed material melted just above 16". When the acid dissolved in 300 times its weight of water and one-third of its weight of potassium hydroxide was oxidised at 0" by the gradual addition of 0.5h7-potassium permanganate dihydroxystearic acid was produced in almost theoretical amount; it was best isolated by filtration after the passage of sulphur dioxide. The substance crystallised from alcohol-benzene melted at 132" alone or mixed with a specimen prepared from oleic acid from olive oil.The melting point 136" given in the literature for this acid is too high. 9-C'arEethoxynona?tilide.-Ethyl hydrogen sebacate (22 g . ) (Grii 178 ROBINSON AND ROBINSON SYNTHESIS OF and Whfh Bey. 1922 55 2207) was heated on the steam-bath for 3 hours with thionyl chloride * (66 g.) the thionyl chloride removed completely by distillation under reduced pressure and exposure of the residue to a vacuum and 9-carbethoxynonoyl chloride thus obtained in good yield treated wit'h an excess of aniline. The aizilide crystallised from light pettroleum containing a little benzene in colourless needles m. p. 63" (Found C = 70.9; H = 8.7. C1,H,,03N requires C = 70.8; H = 8.8%).10-Ketostearic Acid.-The condensation of ethyl sodio-n-heptj-1-malonate with 9-carbethoxynonoyl chloride was carried out like that in the case of the related derivative of acetoacetic acid. The product was an oil which on hydrolysis by alkali gave heptylmalonic and sebacic acids but no ketostearic acid. Dilute sulphuric acid gave a similar result but 1% aqueous oxalic acid caused partial hydrolysis in the desired direction and a very small yield of 10-keto-stearic acid m. p. 77" could be isolated after boiling during a week. The process was obviously unsatisfactory and was abandoned in favour of tlhe following kethod. Sodium (1.2 g.) was granulated under toluene washed with ether, suspended in ether (75 c.c.) and a solution of ethyl 2-acetylnonoate (11-5 g.) (Jourdan Annalen 1879 200 105) in ether (75 c.c.) gradually added.The clear solution of the sodio-derivative obtained by gentle heating was cooled in melting ice and treated with 9-carbethoxynonoyl chloride (12.5 g . ) in ether (20 c.c.). After 1 hour the mixture was boiled for 10 minutes cooled washed with water and the ether evaporated. The residue was shaken with 5% aqueous sodium hydroxide (200 c.c.) for 2 days and then after acidification with acetic acid collected again by means of ether, boiled during 24 hours with 6% sulphuric acid (300 c.c.) and the mixture steam-distilled ; the oil in the distillate was methyl n-octyl ketone (Jourdan Zoc. cit.). The residue in the flask was once more collected by means of ether and boiled during 1.5 hours with 5% aqueous sodium hydroxide (100 c.c.).On cooling the gelatinous precipitate first formed rapidly changed to colourless leaflets, m. p. 212". The acid obtained from this salt crystallised from alcohol and from light petroleum in colourless plates m. p. 83" and a t the same temperature when rnised with 10-ketostearic acid derived from stearolic acid as described below. The two specimens were carefully compared and no differences could be discerned. Stearolic acid was dissolved in concentrated sulphuric acid (6 parts) as recommended by Baruch (Ber. 1884 27 174) but water was not added after 12 hours the solution being filtered by glass wool chloride and 1% of sulphur. * Purified by distillation after boiling under reflux with 1% of aluminiu CERTAIN ICIGIIER ALIPHATIC COMPOUNDS.PART I. 179 and kept in an open vessel. The crust which formed at the surface was removed from time to time drained on porous porcelain, crystallised from alcohol converted into sodium salt which was also crystallised from alcohol finally the recovered acid was crystallised twice from light petroleum and twice from benzene. The product melted at 83" whereas the crude acid melts at about 72" and the highest recorded melting point is 76". 10-Hydroxystearic acid prepared in theoretical yield by the reduction of pure sodium 10-ketostearate in dry alcohol by means of sodium melts at 84.5". This acid yields 10-iodostearic acid by the action of phosphorus fri-iodide and water and Arnaud and Bosternak (Cmpt. rend., 1910,150,1525) have carefully examined the products of the action of alcoholic potassium hydroxide on this iodostearic acid a reaction first investigated by Saytzeff ( J .pr. Chem. 1887 [ii] 35,387). The former authors showed that oleic acid hydroxystearic acid arid isomeric elaidic acids can be isolated. EthyE 2 - Acetyl-n-tridecoate CH,*[CH,] ,,*CHAc*CO,Et .-12*2 Grams of an oil b. p. 185"/17 mm. were obtained according to the usual method employing sodium (1.4 g.) alcohol (17.5 g.) ethyl acetoacetate (11.8 g.) n-undecyl iodide (17 g.) ; the time of reaction was 3-5 hours (Found C = 72.1 ; H = 11.1. C,,H,,O requires 6-Ketostearic Acid (Lactnrinic Acid) .-Ethyl hydrogen adipate, prepared by a method analogous to that employed by Griin and Wirth (Zoc. cit.) in the semi-hydrolysis of diethyl sebacate was converted into the acid chloride by means of pure thionyl chloride.5-Carbethoxyvaleryl chloride (8.5 9.) dissolved in ether (10 c.c.) was added to a solution of ethyl sodio-2-acetyl-n-tridecoate (136 g.) in ether (75 c.c.) at 0" ; after remaining 4 hour at room temperature, the mixture was boiled under reflux for 15 minutes. The washed and isolated product was shaken for 16 hours with 5% aqueous sodium hydroxide (300 c.c.) collected as in the previous example, and boiled with 5% sulphuric acid (600 c.c.) for 24 hours. Steam distillation separated some methyl n-dodecyl ketone m. p. 33-34" (Krafft Eer. 1882 15 1708) and the residue in the flask was collected and heated for 4-5 hours with boiling 5% aqueous sodium hydroxide (200 c.c.).The sodium salt (4-2 g.) which crystallised on cooling was collected and the acid isolated and crystallised from alcohol. The colourless plates melted at 87" alone or mixed with an authentic specimen of lactarinic acid (Pound C = 72.7; H = 11.3. Calc. for C1BH34:3 C = 72.5; H = 11.4%). The o x i m m. p. 59-61 crystallised from light petroleum in microscopic needles and was transformed by concentrated sulphuric acid at 100" into an amide crystallising from alcohol in colourless C == 71.8; H = 11.3%) 180 SYNTHESIS OF CERTAIN HIGHER ALIPHATIC COMPOUNDS. PART I. needles m. p. 104". These m. pt's. agree with those given by Bougault and Charaux (Zoc. cit.). 3 - Carbomethoxypropionanilide CO,Me*CH,*CH,*CO*NHPh .-Methyl hydrogen succinate being a solid m. p. 58" was used in preference to the corresponding ethyl derivative in the synthesis of 4-ketopalmitic acid.Succinic anhydride conveniently obtained by the action of thionyl chloride on the acid was converted into the semi-ester by the method of Bone Sprankling and Sudborough (J. 1904 85 530). 3-Carbomethoxy~ro,/r,ionyl chloride derived from the acid by the action of thionyl chloride is a colourless liquid, b. p. 93"/18 mm. and reacts with aniline with formation of 3-carbo-methoxypropionanilide which crystallises from light petroleum-benzene as also from ether in colourless needles m. p. 97-99' (Found C = 63-8 ; H = 6.4. Calc. for C1lH,,O,N C = 63.7 ; H = 6.3%). The same substance has been prepared by the action of methyl alcohol and hydrogen chloride on succinanil (van der Meulen Rec.trav. chim. 1896 15 341 ; Eioogewerth and van Dorp, ibid. 1898,1'7,200). 4-Ketopalmitic Acid.-A solution of 3-carbomethoxypropionyl chloride (ti g.) in ether (30 c.c.) was added to the sodio-derivative from ethyl 2-acetyl-n-tridecoate (1 1 g.) and granulated sodium (0.9 g.) in ether (320 c.c.). The mixture was cooled in ice-water, kept over-night and boiled under reflux for 8 hour. The washed and isolated product was hydrolysed by shaking for 6 hours with 5% potassium hydroxide (300 c.c.) boiling for 30 hours with 5% sulphuric acid (250 c.c.) and for 3 hours with 5% potassium hydroxide. The potassium salt did not separate on cooling and, on acidification of the solution 5-1 g. of almost pure 4-ketopalmitic acid were obtained. The substance crystallises from light petroleum in colourless clusters of waxy lanceolate plates m. p. 91-92" (Found C = 71.3 ; H = 11.0. C,,H,,O requires C = 71.1 ; H = 11.1 %). The oxime is readily soluble in most organic solvents and crystallises from light petroleum in colourless needles m. p. 54". We desire to express our thanks to the Food Inves-bigation Board for grants which have eiiabled one of us to take part in this investigation. TIIE UNIVERSITY MANCHESTER. [Received November loth 1924.