A New Catalyst for the Enantioselective Sulfur Ylide Epoxidation

Significance

A new organosulfide, derived from d-camphor, was found to catalyze the reaction between aldehydes and benzyl bromide to furnish trans-epoxides in excellent diastereo- and good enantioselectivities and yields. Catalyst 1 was obtained as a side product during the synthesis of another catalyst through an unexpected Wagner-Meerwein rearrangement. It proved to be a more efficient catalyst than the originally desired compound. The choice of base and additive also had crucial effects on the reaction outcome.