A Novel Approach Towards <i>cis-</i> and <i>trans-</i>Fused Pyranopyrans Based on Ring-Closing Metathesis Reaction of Carbohydrate Derivatives

Abstract

A novel synthesis of both cis- and trans-fused pyranopyran systems, based on ring-closing metathesis of glycal derived dienes, is described. Isomerisation of the resulting allylic double bond provides a new cyclic enol ether, thus opening the way to an iterative synthesis of cis-(trans-)fused cyclic polyethers.