The constitution of umbellulone. [Pt. I] / by Frank Tutin.

  • Tutin, Frank.
Date:
[1906]
Catalogue details

Licence: Attribution 4.0 International (CC BY 4.0)

Credit: The constitution of umbellulone. [Pt. I] / 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.

    14/24 (page 1115)
    presence in the essential oil of Californian Laurel of a substance which has not been identified. The benzene mother liquors from this acid yielded a quantity of a-homopiperonylic acid, which was undoubtedy derived from the safrole contained in the original oil (Power and Lees, loc. cit ). Although other acids were certainly present in this mixture, and also in that obtained from the fraction of esters boiling at 135—165°/20 mm., they could not be separated. By the oxidation of umbellulone under the conditions employed, no derivative other than umbellulonic acid could therefore be isolated. Oxidation of Pure Umbellulone.—Thirty grams of the umbellulone fraction were treated with semicarbazide, the resulting semicar bazido- semicarbazone washed with ether until free from adhering oil, then decomposed with dilute sulphuric acid, and the regenerated umbellulone isolated. This was subsequently oxidised with potassium permanganate under the same conditions as were employed when oxidising the umbel- lulone fraction of the oil. The resulting acids yielded some lactone on distillation, and, when converted into their ethyl esters, gave ethyl umbellulonate and a comparatively small proportion of a mixture of esters which distilled from 135—172°. Umbellulonic acid, therefore, is not the only product of the oxidation of umbellulone. Oxidation of the Lactone. Formation of Umhellularic Acid.—Thirty grams of the pure lactone were shaken into an emulsion with 600 c.c. of water, and a 4 per cent, solution of potassium permanganate gradually added with constant shaking, the mixture being kept cool by immersion in cold water. When an amount of permanganate equivalent to four atomic proportions of oxygen had been added, the pink colour was no longer discharged. A moderate excess of the oxidising agent was then added, and the mixture allowed to stand for some hours, when apparently no more potassium permanganate became decolorised. The excess was then removed by means of sulphurous acid, and the precipitated manganese dioxide was separated by filtration. The liquid was subsequently concentrated to a small bulk, acidified with sulphuric acid, and repeatedly extracted with ether; the ethereal liquid was then washed, dried, and the ether removed. The residue was an almost colourless syrup, which, after standing for a few hours, became entirely crystalline. When fractionally crystallised from benzene, this acid was found to be homogeneous, as all the fractions yielded colourless prisms which melted sharply at 120—121°. 0-1062 gave 0-2176 COg and 0-0661 H2O. C = 55*88 ; H = 6-91. CgHj20^ requires C = 55-81; H = 6-98 per cent. 0'5111 dissolved in 25 c.c. of chloroform had au - 3°40' in a 2-dcm. tube, hence'.[a]i) -89-7°.