Diastereoselective radical cyclization of bromoacetals: Efficient synthesis of (±)-botryodiplodin

Abstract

A stereoselective synthesis of (±)-botryodiplodin is presented. The key reaction is a radical cyclization of a bromoacetal (Ueno-Stork reaction). The stereogenic acetal center has been used to control the stereoselectivity of the process: the difficulty in controlling the stereochemistry at C(3) of the tetrahydrofuran moiety during the cyclization step has been overcome by a double one-pot reduction procedure starting from a gem-dibromide. [Display omitted]