The constitution of umbellulone. Pt. III / by Frank Tutin.

  • Tutin, Frank.
Date:
1908
Catalogue details

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: The constitution of umbellulone. Pt. III / by Frank Tutin. 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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    uinbellulone, I had designated as “ ^-dibydroiuiibellulone.” In the first place, however, consideration may be given to the character of the “ umbellulone ” employed by Semmler. The material available to Semmler for the purpose of his investigation of umbellulone consisted of 100 grams of the essential oil of Unibellularia Ccilifornica which had been supplied to him, at his request, by Dr. Power. This oil was a portion of the identical material which had been used in my work on umbellulone. It is stated by Semmler that the umbellulone can be separated from this oil by fractional distilla- tion, but this is not strictly correct, as by this means it is impossible to obtain the pure ketone. Power and Lees (loc. cit.), by a very7 careful and prolonged fractionation of 1200 gi’ams of the oil, obtained a fraction boiling at 217—222° (aD - 36°33' in a 1-dem. tube) which gave, on analysis, C = 78,9; H = 9,9. On subjecting this to further fractionation, a portion was obtained which boiled constantly at 218°, and, on analysis, gave C = 79T; II = 9-8. Since C10H14O requires C = 8(M); H = 9‘3, and C10H10O requires C = 78‘9; H = 10‘5, these fractions were evidently mixtures. Moreover, on treating the fraction, b. p. 217—222°, with semicarbazide, it gave, at the most, only 55 per cent, of the theoretical yield of semicarbazidodihydroumbellulone- semicarbazone. That this deficiency is not due solely to the incom- plete interaction of the ketone and the base, is seen from the fact that a very much better yield of the semicarbazido-derivative may bo obtained by employing pure, regenerated umbellulone, Umbellulone, when regenerated from its semicarbazidosemicarbazone, has aD - 37° in a 1-dcm. tube, and gave C = 7D‘7; H = 9‘3 (C10H14O requires C = 80’0; H = 9'3 per cent.). Since the product which Semmler regarded as umbellulone had aD - 31°30' in a 1-dcm. tube, it was evidently still more impure than the fraction (b. p. 217—222°, aD - 36° 33') obtained by Power and Lees, which, as shown above, and as recognised by them, was a mixture of substances. It was therefore with consideration of the uncertainty regarding the composition of the fraction of the essential oil of U. Ccilifornica which contains umbellulone that my inferences concerning the constitution of the latter were based only on the products obtained from the pure, regenerated ketone. /3-Dihydroumbellulone. The “ umbellulone ” which was submitted to the action of sodium and alcohol, both in my experiments and in those conducted by Semmler, was only a particular fraction of the essential oil. As pointed out above, this material is not pure umbellulone, but gives results on analysis which are approximately the mean of those which