Formal [4 + 1]-Cycloaddition of Homopropargyl Alcohols to Diazo Dicarbonyl Compounds Giving Substituted Tetrahydrofurans

Abstract

A novel formal [4 + 1]-cycloaddition of readily available homopropargyl alcohols with diazo dicarbonyl compounds is described, which involves tandem O–H insertion/Conia-ene cyclization under cooperative Rh­(II)/Zn­(II) catalysis. This reaction provides easy access to various substituted tetra­hydro­furans and exhibits complete <i>E</i>-selectivity in the case of nonterminal alkynes