Conrotatory ring opening of a cyclobuteno-benzo[b]thiepine and rearrangement of the resulting cis,trans-benzo[b]thionine

Abstract

The opening of a bicycllic cyclobutene to a nine-membered ring with cis,trans configuration of the resulting butadiene, and the consecutive thermal transformation of this compound to the cis,cis isomer has been demonstrated by X-ray analysis; the kinetics of the cis,trans to cis,cis transformation have been studied, and both the cis,trans and the cis,cis compounds have been resolved into optical antipodes by chromatography on swollen, microcrystalline triacetylcellulose.