| abstract |
gamma -butyrolactones of the general formula I <IMAGE> (I) where R1 is hydrogen or alkyl of 1 to 4 carbon atoms which may be substituted by lower alkoxy or acyloxy and R2 is hydrogen or straight-chain or branched alkyl which is unsubstituted or substituted by a functional group or is aryl, are prepared by reacting an alkylene oxide of the general formula II <IMAGE> (II) with an acylacetate of the general formla III <IMAGE> (III) where R1 and R2 have the above meanings and R3 and R4 are each alkyl of 1 to 6 carbon atoms or aryl, and R4 may furthermore be hydrogen, in the presence of a catalyst at elevated temperatures, by a process in which the reaction is carried out in the presence of an alkali metal halide, of an ammonium halide, preferably a quaternary ammonium halide, of a phosphonium halide, of an alkali metal phosphate or of an alkali metal carbonate at from 20 DEG to 200 DEG C. and under from 1 to 50 bar. |