Synthesis of a C1-C9 fragment of rhizoxin

A C1-C9 fragment of the antitumour macrolide rhizoxin has been synthesised. An Evans' asymmetric aldol reaction was used to set up the first two chiral centres, and an α,β-unsaturated δ-lactone was then formed on the acyclic system by an intramolecular Wadsworth-Emmons reaction. Stereoselective hydrogenation was used to set up the cis relative stereochemistry in the saturated δ-lactone ring. (C) 2000 Published by Elsevier Science Ltd.