Preparation of lactones

摘要

7-Substituted lower alkyl hept-6-enoates and 4-hydroxytetrahydropyran-2-ones bearing 6-olefinic substituents (e.g.,) ethyl erythro-3,5-dihydroxy-7-phenyl-hept-6-enoates are prepared by a multi-step process. The process involves 3-protected-lower alkyl 3,5-dihydroxy-hept-6-enoates, which are obtained by cleaving corresponding 6 alpha -vinyl-4 beta -protected hydroxy-tetrahydro 2H-pyran-2-ones. The final products are useful as anti hypercholesteremic agents.