RADICAL CYCLIZATION ONTO 2(5H)-FURANONE AND MALEATE ELECTROPHORES. AN APPROACH TO THE SPIRO- AND LINEAR-FUSED γ-LACTONE RING SYSTEMS FOUND IN THE GINKGOLIDES

Article abstract of DOI:10.1016/S0040-4020(01)81099-1

Intramolecular radical cyclizations involving α-acetal methyl centres, and 2(5H)-furanone and maleate electrophores, allow the facile synthesis of spiro- and linear-fused γ-lactone ring systems e.g. (5), (6), (7) and (8) present in the 'ginkgolides' viz (1) and (2) produced by the ginko tree Ginkgo biloba.