Synthesis of 1-Aza-8-thiabicyclo[4.2.1]nona-2,4-diene 8,8-Dioxide and Its Conversion to a Strained Spirocycle via Photoinduced SO₂−N Bond Cleavage

Abstract

A route to the doubly unsaturated bridgehead sultam 12 has been developed. When irradiated at 350 nm, this conjugated diene is isomerized via a two-photon process to the structurally novel spiro heterocycle 17 constituted of cyclobutene, thietane dioxide, and pyrrolidine rings. A probable mechanism for the generation of 17 and select reactions thereof are reported. [reaction: see text]