HIGHLY STEREOSELECTIVE NUCLEOPHILIC EPOXIDATION OF SIMPLE VINYL SULFOXIDES

The nucleophilic epoxidation of readily available vinyl and dienyl sul foxides with MOO-t-Bu (M = Li, Na, K) takes place in good yields, with complete preservation of double bond geometry in most cases and with moderate to excellent diastereofacial selectivity to produce enantio- and diastereomerically pure cr,P-epoxy sulfoxides, valuable synthetic intermediates. Subsequent straightforward oxidation at sulfur affords the corresponding enantiopure sulfonyl oxiranes. For (1E)-2-sulfinyl d ienes, the facial selectivity of this novel process may be controlled by the choice of metal (Li vs Na).