A Synthetic Intermediate for Trichothecane Phytotoxic Sesquiterpenoids

Abstract

A number of sesquiterpenoid mold metabolites have been isolated and characterized recently. One important class of these naturally occurring substances, the trichothecane group, possesses an eminent degree of phytotoxic activity against certain pathogenic fungi.¹ The least structurally complicated member of this important class of mold metabolites is (-)-trichodermin (1). The structure and absolute stereochemistry of this unique phytotoxic metabolite was determined from chemical, spectroscopic, and X-ray diffraction data.^2,3,4 Recently Colvin, Raphael, and Roberts reported an elegant total synthesis of racemic trichodermin via (±)-lactone 2b (R[dbnd]CH₃).⁵ We wish to report, herein, a synthesis of optically active (+)-lactone 2b (R[dbnd]CH₃).⁶