Synthesis of Diverse γ-Aryl-β-ketoesters via Aryne Intermediates Generated by C-C Bond Cleavage

A synthetic method for diverse gamma-aryl-beta-ketoesters through gamma-aryl-beta-ketoester-type arynes triggered by C-C bond cleavage has been developed. The Mukaiyama aldol reaction of 6-(triflyloxy)benzocyclobutenones with ketene silyl acetals and subsequent treatment of resulting 6-(triflyloxy)benzocyclobutenols with a base triggered the efficient generation of gamma-aryl-beta-ketoester-type arynes, which reacted with various arynophiles to provide a wide range of yaryl-beta-ketoesters. The synthetic utility of the method was demonstrated by the synthesis of an analog of ALK inhibitor.