Oxidation of 1, 3-oxathiolan-5-ones (1) gives acceptable yields of sulfoxides only when C4 is unsubstituted. Sulfoxides derived from 1, 3-thiazolidine-4-ones (8) are easily prepared. Acid- catalyzed rearrangement in the presence of 1-alkenes or benzene leads to alkylation (arylation) at C5. Alkylation of 8 c may be generally more effective than that of 1. An aldol condensation of 8 c shows little stereoselectivity.
