method for preparing (part 2.2 - disubstitue) - gamma butyrolactones

摘要

1503858 Preparation of (2,2-disubstituted vinyl)-γ-butyrolactones CHEMINOVA A/S 31 Dec 1976 [21 Jan 1976 25 May 1976] 02380/76 and 21631/76 Heading C2C A process for the preparation of a (2,2-disubstituted vinyl)-γ-butyrolactone of the formula in which R 1 and R 2 , which may be the same or different, are hydrogen or an alkyl group having 1 to 6 carbon atoms; R 3 and R 4 , which may be the same or different, are hydrogen, an alkyl group having 1 to 6 carbon atoms or a halogen atom, or, together with the carbon atom to which they are attached, form a cycloalkyl group, and R 5 is an alkyl group having 1 to 6 carbon atoms, comprises condensing an epoxide of the formula in which R 1 , R 2 , R 3 and R 4 have the abovestated meanings, with a malonic acid ester of the formula in which R 5 has the above-stated meaning, in a basic medium, and optionally in the presence of a solvent, e.g. an alcohol of the formula R 5 OH. The epoxide is suitably prepared by reacting a diene of the formula with a metal oxyhalide under alkaline conditions, or oxidizing said diene, e.g. by means of a per-acid in the presence of an inert solvent. A modification of the above process of the invention comprises reacting the malonic acid ester of Formula IV with a hydroxy-halogen compound of the formula wherein X is a halogen, under basic conditions.