How Stable Are Epoxides? A Novel Synthesis of Epothilone B.

Remarkable stability of the oxirane function is displayed over a number of synthetic operations in a novel synthesis of the antitumor compound epothilone B (see scheme). The cis-epoxide, generated very early by dihydroxylation of an (E)-olefin, was resistant to more than ten synthetic steps under a wide variety of reaction conditions. TBS=tert-butyldimethylsilyl.