ASYMMETRIC SYNTHESIS OF β-SUBSTITUTED γ-BUTYROLACTONES

Abstract
Highly optically pure β-substituted γ-butyrolactones (V) were obtained in good yields by the reaction of (E)-(2R,3S)-6-alkylidene-3,4-dimethyl-2-phenylperhydro-1,4-oxazepine-5,7-dione (I) with phenylthiomethyllithium, followed by i) treatment with trimethyloxonium tetrafluoroborate and ii) acid hydrolysis.