Radical cyclization of exo-methylene furanose derivatives: an expedient approach to the synthesis of chiral tricyclic nucleosides and benzannulated oxepine derivatives

Abstract

Tributyltin radical mediated cyclization of the glucose derived exo-methylene furanose derivatives 5a– c led to the highly functionalized cis-fused bicyclic ethers 6a– c . The product could subsequently be transformed to the optically active tricyclic nucleoside analogue 8 or oxepine derivative 9 .