Prepn of beta-lactones by contacting dialkylhydroxy

摘要

Beta-lactones (R1 and R2 denote alkyl radicals esp. C1-4 alkyl radicals). are obtd. by contacting an alpha,alpha-dialkyl-beta-hydroxycarboxylic acid HO-CH2-C(R1)(R2)-COOH and/or one or more of its esters with an inorganic acid, in gaseous phase at temps. between 150 deg. and 450 deg.C with one or more solid oxides of elements of subgroups A and B of Groups III and IV. No solvent or only small amts. of solvent are used obviating the disadvantages of Brit. 1072238 which requires extensive facilities for removing or recycling solvent. The beta-lactones are polymerized to polyesters using polymerization initiators, e.g. as in Brit. 1028928.