Intramolecular [4 + 2] cycloadditions involving transient phosphaalkene intermediates as dienophiles: a useful entry to phosphabicyclo[4.3.0]non-4-ene derivatives

Abstract

Three representative phosphabicyclo[4.3.0]non-4-ene derivatives are formed in high yields and various diastereomeric forms by [4 + 2] intramolecular cycloadditions involving transient phosphaalkenes as dienophiles; complete diastereoselectivity is observed with the P-substituted derivative.