Intramolecular Reactions of Hydroperoxides and Oxetanes:  Stereoselective Synthesis of 1,2-Dioxolanes and 1,2-Dioxanes

Abstract

[reactions: see text] The 5-exo openings of oxetanes by hydroperoxides proceed rapidly and stereospecifically to furnish 1,2-dioxolanes. The corresponding 6-exo cyclizations are slower and proceed with moderate stereoselectivity. In the case of hydroperoxy acetals, 5-exo nucleophilic transfer of alkoxide competes effectively with 6-exo attack by the hydroperoxide.