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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    Ethyl Ghaulmoograte, C1^H31*C02Et. Ethyl chaulmoograte was prepared in the same manner as the methyl ester ; it boiled at 230° corr./20 mm., and is a colourless oil. 0T356 gave 0*3866 002 and 0T438 H20. C = 77*8; H=ll*8. 0*1090 „ 0*3112 C02 „ 0*1168 H20. C = 77*9; H = 11*9. C20H36O2 requires C = 77*9 ; 11 = 11 *7 per cent. dl5°/l 6° = 0*9079 ; aD +46° in a 1 dcm. tube, whence [a]i,0° +50*7°. A specimen of this ester was sent to Dr. W. H. Perkin, sen., who very kindly determined its density, magnetic rotation, and refractive power, with the following results : Density determinations'. <710°/10° 0*91064; <715°/15° 0*90741 ; d20°/20° 0*90456. Magnetic Rotation. 1. t. Sp. rotation. Mol. rotation. Optical rotation. (1) 175 mm. 13*9° 1*1189 21*065 [a]D +50*69° (2) 104 mm. 14*3 1*1115 20*976 [a]D +50*73 Average molecular rotation, 21*020. The calculated values on the basis of ethyl stearate, C20H40O2, mol. rot. 20 797, (1) with two unsaturated linkings ( — H2 x 2 = + 1*112 x 2); (2) with ring formation (- 0*6) and a single unsaturated linking (-H2 = +1*112); (3) with ring formation (-0*6) and a single allyl group ( - H2= + 0*913), are as follows : Mol. rotation. Ethyl Stearate 20*797 (1) Two unsaturated linkings ( — H2 x 2 =+1*112 x 2) 2*224 23*021 Ethyl stearate 20*797 (2) Ping formation ( - 0*6) 0*600 20*197 One unsaturated linking ( - H2= + 1*112) 1*112 21*309 Ethyl stearate 20*797 (3) Ring formation (— 0*6) 0*600 20*197 One allyl group (-H2= + 0*913) 0*913 21*110