T. Kitamura et al., COMPLETE RETENTION OF CONFIGURATION IN THE NUCLEOPHILIC-SUBSTITUTION OF 1-PHENYLBENZO[B]THIOPHENIUM SALTS BY ALKOXIDE ANIONS, Journal of the Chemical Society, Chemical Communications, (13), 1995, pp. 1375-1376
Reaction of 1,2,3-triarylbenzo[b]thiophenium salts with alkoxide anion
s results in:the exclusive formation of (Z) alkoxy-substituted alkenes
, indicating that the nucleophilic ring-opening reaction proceeds with
complete retention of configuration.