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

  • Tutin, Frank.
Date:
1907
Catalogue details

Licence: In copyright

Credit: The constitution of umbellulone. Pt. II / 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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    acidifying the alkaline aqueous liquid thus obtained, an oily acid separated. This was isolated by means of ether, and distilled under 120 mm. pressure, when it was evident that lactone formation ensued, as a considerable quantity of water was eliminated. The distillate was dissolved in ether, freed from any traces of acids by means of sodium carbonate, and the ethereal liquid washed, dried, and evaporated. On distilling the residual oil under the atmospheric pressure it was found to boil from 246—248°, and amounted to 1T3 grams : 0-1092 gave 0-2776 00.^ and 0-0982 HgO. 0 = 69-3 ; H = 10-0. 0-1163 „ 0-2951 „ „ 0-1049 HjO. 0 = 69-2; H= 10-0. 0-0992 „ 0-2514 „ „ 0-0893 HgO. 0 = 69-1 ; H= 10-0. CgHjgOg requires 0 = 69-2 j 11 = 10-2 per cent. This substance, as has been shown in the introductory portion of this paper, is the lactone of \-^hyd.roxy-a-isopropyl-n-hexoic acid ; it is a colourless, mobile liquid, possessing a pleasant odour : 0-5229 dissolved in 25 c.c. of absolute alcohol gave ap - 0°34' in a 2-dcm. tube, whence [ajx, — 13-54°. On boiling this lactone with a solution of potassium hydroxide, the potassium salt of the corresponding hydroxy-acid was readily formed. This has a Isevorotation in aqueous solution, and when treated with dilute sulphuric acid gives Z-8-hydroxy-a-fsopropyl-«-hexoic acid. This hydroxy- acid, in the cold, does not pass spontaneously into the corresponding lactone, but this change readily occurs under the influence of heat. Silver \-h-hydroxy-a-isopropyl-n-Jiexoate crystallises from hot water in colourless needles. On analysis : 0-1268 gave 0-0487 Ag. Ag = 38-4. CgHj^OgAg requires Ag = 38-4 per cent. Oxidation of l-h-Hydroxy-a-isopropyl-n-hexoic Acid with Potassium Permanganate. Formation of imPropylsuccinic and Acetic Acids. About 10 grams of the lactone were dissolved in a considerable excess of hot aqueous potassium hydroxide, the solution cooled, and diluted to about 1-5 litres. A quantity of a 3 per cent, solution of potassium permanganate equivalent to between two and three atomic proportions of oxygen, was then added. Oxidation proceeded slowly, but after some hours the colour of the permanganate was discharged. The filtered liquid was concentrated to a small bulk, acidified with sulphuric acid, and distilled in steam, when a quantity (about 5 grams) of the original lactone slowly passed over. The distillate, which had an acid reaction, was rendered alkaline by the addition of sodium car- bonate, and the lactone removed by means of ether, after which the alkaline liquid was acidified and again distilled in steam. The acida