Powerful Claisen condensation and Claisen–aldol tandem reaction of α,α-dialkylated esters promoted by ZrCl4–iPr2NEt

Abstract

Powerful Claisen ester condensations of α,α-dialkylated esters mediated by ZrCl₄–ⁱPr₂NEt were performed to give the corresponding thermodynamically unfavorable α,α-dialkylated β-ketoesters, and Claisen–aldol tandem reactions between an intermediary Zr-enolate of a α,α-dialkylated β-ketoester and aldehydes also proceeded.