The constitution of chaulmoogric and hydnocarpic acids / by Marmaduke Barrowcliff and Frederick B. Power.

  • Barrowcliff, Marmaduke.
Date:
1907
Catalogue details

Licence: In copyright

Credit: The constitution of chaulmoogric and hydnocarpic acids / by Marmaduke Barrowcliff and Frederick B. Power. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    0'3360 gram in 100 c.c. of chloroform gave ap +0°5' in a 2-dcm. tube, whence [aju + 12’4°. The ester was hydrolysed and the acid extracted and crystallised from ethyl acetate, in which it was readily soluble. It separated in clusters of small, silky needles, melting at 105°: 0-0944 gave 0-2368 COg and 0-0922 HgO. C = 68-4 ; H = 10-8. CjsHg^O^ requires C = 68-8 ; H= 10-8 per cent. 0-5008 gram in 100 c.c. of alsolute alcohol gave ao +0°7' in a 2-dcm. tube, whence [ajn -fll-6°. This acid is thus shown to be a dihydroxydihydrochaulmoogric acid, and was found to be identical with the acid of the same composition described in the previous communication, the melting point of which was given as 102° (Trans., 1904, 85, 860). The mother liquors from the crystallisation of the ester melting at 75—76° were found to be Isevorotatory, and from them an ester was isolated which, after several crystallisations, melted at 68—69°. This ester crystallised in silky needles, and was much more soluble in methyl alcohol than the one of higher melting point which was pre- viously isolated : 0-8420 gram in 100 c.c. of chloroform gave an -0°16' in a 2-dcm. tube, whence [a]o - 15-8°. On hydrolysing this ester an acid was obtained which, after two crystallisations from ethyl acetate, melted at 92—93° : 0-1004 gave 0-2520 COg and 0-0986 HgO. 0 = 68-5; H=10-9. CigH3202(0H)2 requires 0 = 68-8 ; H= 10-8 per cent. 0-2936 gram in 25 c.c. of absolute alcohol gave oj, - 0°20' in a 2-dcm. tube, whence [aju -14-2°. This acid is therefore an isomeride of that melting at 105°, but it is much more sparingly soluble in ethyl acetate than the latter. Both these acids yield sodium salts which are only sparingly soluble in cold water. Fraction 275—290°/l6 mm.—This evidently also contained some of the two dihydi'oxydihydrochaulmoogric acids which were isolated from the preceding fraction. Oxidation of Chaulmoogric Acid in Alkaline Solution with Potassium Permanganate (0 = 4 Atomic Equivalents).—One hundred grams of chaulmoogric acid were dissolved in the same amount of solution of potassium hydroxide as in the preceding experiment, and to this was added a solution of 150 grams of potassium permanganate in 8 litres of water, the tempei-ature of the mixture being kept at 15—18°. The acids were extracted, converted into their methyl esters, and frac- tionally distilled under a pressure of 15 mm. Several fractions were
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