The constitution of chaulmoogric and hydnocarpic acids / by Marmaduke Barrowcliff and Frederick B. Power.
- Barrowcliff, Marmaduke.
- Date:
- [1907]
Licence: In copyright
Credit: The constitution of chaulmoogric and hydnocarpic acids / by Marmaduke Barrowcliff and Frederick B. Power. Source: Wellcome Collection.
13/26 page 567
![collected, of which those boiling at 265—275° and 275—285°/15 mm. solidified on cooling. Isolation of a IlydroxyJcetodihydrochaulmoogric Acid, ClVH30O(OH)-CO,H. Fraction 265—275°/15 mm.—This was the larger of the two fractions, and on analysis it gave the following result: 0-0961 gave 0-2410 C02 and 0*0882 H20. C = 68-4; H=10*2 percent. After being brought on a porous plate to remove adhering oil, the solid ester was crystallised several times from methyl alcohol, when it separated in needles melting at 64°, and this melting point was not altered by further crystallisation : 0-1051 gave 0-2697 C02 and 0*0986 H20. C = 70-0; H = 10*4. 0-1003 „ 0-2577 C02 „ 0-0940 H20. C = 70-1; H= 10-4. Ci9H3404 requires C = 699 ; H = 10*4 per cent. The solid which separated from the fraction 275—285°/15 mm. likewise consisted of the above-described ester. The ester was hydrolysed, and the acid extracted and crystallised from alcohol, from which it separated in needles melting at 90°. It was very soluble in cold ethyl acetate, but less freely in alcohol : 0-1162 gave 0-2946 C02 and 0*1060 H20. 0 = 69-1; H = 10-l. 0-1013 „ 0-2573 C02 „ 0-0920 HgO. C = 69*3 ; H = 10T. 0-0984 „ 0-2477 C02 „ 0-0913 H20. 0 = 68*8; H = 10*3. C18H3204 requires C = 69'2 ; H = 10-3 per cent. C]7H30O4 „ 0 = 68-4; H = 101 „ From these results it is evident that the acid has the formula Ci8H3204. Both acid and ester were optically inactive. The methyl ester, when treated with semicarbazide hydrochloride and sodium acetate, yielded a semicarbazone which crystallised from alcohol in small needles melting at 110°. This shows the ester to be that of a hydroxyketodihydrochaulmoogric acid. 0-5108 of the ester required for hydrolysis 6-4 c.c. Nj'2 NaOH, the calculated amount for C16H2902(C0.,Me) being 3*1 c.c. The fact that this substance, although the ester of a monocarboxylic acid, when heated with an excess of alkali neutralises two equi¬ valents of the latter, is probably due to hydrolysis of the grouping •CH(OH)*CO* in the ring, with the formation of a dibasic hydroxy- acid, C18H340„ and the latter then apparently loses water, yielding a lactonic acid, C18H3l)04. This assumption receives support from the fact that no semicarbazone could be obtained from the acid furnished by the hydrolysis of the ester, and, on re-esterifying the acid, instead of the original ester, a fatty substance was obtained. The amount of material available was insufficient for its further investigation.](https://iiif.wellcomecollection.org/image/b30611751_0013.jp2/full/800%2C/0/default.jpg)
