Reactions of <i>o</i>‑Quinone Methides with Pyridinium Methylides: A Diastereoselective Synthesis of 1,2-Dihydronaphtho[2,1‑<i>b</i>]furans and 2,3-Dihydrobenzofurans

Abstract

A simple, general route to the 1,2-dihydronaphtho­[2,1-<i>b</i>]­furans and 2,3-dihydrobenzofurans substituted at C-2 by an acyl or aryl group, starting from phenolic Mannich bases and pyridinium ylides, has been developed. The mechanism of the reaction is believed to involve the formation of the <i>o</i>-quinone methide intermediate, Michael-type addition of the ylide to the <i>o</i>-quinone methide, followed by intramolecular nucleophilic substitution