The constitution of chaulmoogric acid : Pt. 1 / by Frederick B. Power and Frank H. Gornall.

  • Power, Frederick B. (Frederick Belding), 1853-1927
Date:
[1904.]
Catalogue details

Licence: In copyright

Credit: The constitution of chaulmoogric acid : Pt. 1 / by Frederick B. Power and Frank H. Gornall. Source: Wellcome Collection.

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    would thus at first sight appear to belong to the series CnH2W_402, which includes its isomerides linolic and tariric acids, both of which also occur in fatty oils. These two acids, however, form tetra- bromides, and, under certain conditions, combine respectively with four atomic proportions of iodine, whereas chaulmoogric acid inter¬ acts with only two atomic proportions of these elements. It there¬ fore became evident that chaulmoogric acid possesses only one ethylenic linking, and must necessarily contain in its structure a closed ring, a conclusion which has been amply borne out by further investigation. It is the possession of the latter feature which specially differentiates chaulmoogric acid from any of the known naturally occurring fatty acids. With the object of eventually elucidating the constitution of chaul¬ moogric acid, a number of its derivatives have been prepared and studied, and some of the results thus far obtained are given in this communication. When chaulmoogric acid is treated with methyl alcohol and hydrogen chloride, methyl chaulmoograte, Cl7H31*C02Me, is produced, ethyl chaulmoograte, C1^H31,C02Et, being obtained in a similar manner. Chaulmoogramide, Cl7H31*CO*NH2, was prepared according to Aschan’s method (Ber., 1898, 31, 2344). When chaulmoogric acid is treated with hydrogen bromide in glacial acetic acid, the optically inactive bromodihydrochaulmoogric acid, Cl7H32Br#C02H (m. p. 36—38°), is produced. When ethyl chaulmoograte, in chloroform solution, is treated in the cold with an excess of bromine, it readily combines with two atomic proportions of the latter, forming ethyl dibromodihydrochaul- moograte, C1^H31Br2*C02Et, which is a yellow oil. When chaulmoogric acid was treated with sodium and amyl alcohol, its ethylenic linking was not resolved, but chctulmoogryl alcohol, C18H33*OH, and chaulmoogryl chaulmoograte, C]7H31*C02*C18H33, were obtained. The former is evidently produced by the reduction of the esters of chaulmoogric acid, which would be formed in small amount by the interaction of the acid and the amyl alcohol prior to the introduction of the sodium (compare Bouveault and Blanc, Compt. rend., 1903, 137, 328). The formation of chaulmoogryl chaulmoograte took place during the subsequent fractional distillation of the mixture of chaulmoogryl alcohol and unchanged chaulmoogric acid. When, however, bromodihydrochaulmoogric acid is treated with zinc dust and alcohol, or chaulmoogric acid with hydriodic acid and phosphorus, the saturated compound, dihydrochaulmoogric acid, C17H 33*C02H, is formed; the methyl ester, C^H^'CC^Me, of the latter acid was also prepared. The last-mentioned method of reduc-