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

  • Frederick Belding Power
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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    tion also yielded a hydrocarbon, chaulmoogrene, which, on analysis, gave figures agreeing with the formula C18H34. When chaulmoogric acid was oxidised with cold permanganate in amount equivalent to 1 atomic proportion of oxygen, dihydro'xy- dihydrochaulmoogric acid, Cl7H31(0H)2*C02H, was isolated. When, however, an amount of permanganate equivalent to 4—5 atomic pro¬ portions of oxygen was employed, a mixture of several acids was obtained, from which were isolated formic acid and two dibasic acids having the formulae C15H28(C02H)2 (ethyl ester, C15H28(C02Et)2) and C15H280(C02H)2. The ethyl ester of the latter acid, C15H280(C02Et)2, was also prepared. Dr. W. H. Perkin, sen., very kindly determined for us the magnetic rotation and refractive power of ethyl chaulmoograte. The molecular rotatory power of this compound was found to approximate very closely to the calculated value for an unsaturated substance having the formula C20H36O2, possessing a closed ring and one ethylenic linking, the latter being contained in an allyl group. Dr. Perkin’s suggestion that chaulmoogric acid might contain an allyl group was made prior to the isolation of formic acid and the two acids having the formulae Cl7H30O4 and Cl7H30O5, and these results have therefore confirmed the correctness of this assumption. Experimental. Methyl Chaulmoograte, Cl7H31*C02Me. Fifteen grams of chaulmoogric acid were dissolved in 30 grams of methyl alcohol and a current of hydrogen chloride passed into the warm solution during two hours. The ester soon separated as an oily layer, which, on cooling, became solid ; water was then added and the whole extracted with ether. The ethereal solution was washed successively with water, then several times with 10 per cent, aqueous sodium carbonate, and finally with water, dried, the ether removed, and the residual oil distilled under diminished pressure. It practically all passed over at 227° corr./20 mm. as a colourless oil, which, on cooling, formed a solid mass of needles, melting at 22°. 0-1185 gave 0-3368 C02 and 0*1265 H20. C = 77’5; H = ll-8. 0-1209 „ 0-3422 C02 „ 0*1290 H20. C = 77*2 ; H= 11*8. C19H3402 requires C = 77*6 ; H= 11*6 per cent. d25°/25° = 0*9119 ; aD + 46°4/ina 1 dcm. tube, whence [a]D +50-5°. Five grams in 100 c.c. of chloroform gave an +lc14' in a 50 mm, tube, whence [a]JJ' +50°.
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