One-pot stereoselective synthesis of (Z)-diethyl α-chlorovinylphosphonates

Abstract

Diethyl trichloromethylphosphonate, treated with BuLi followed by an aldehyde (or cycloalkenone), was converted to α-chlorovinylphosphonates via the intermediate formation of a bisphosphonate and a Wadsworth–Emmons olefination. High (Z) stereoselectivity of the reaction is discussed in terms of the conformational preferences of the adducts.