From Carbamate to Chalcone: Consecutive Anionic Fries Rearrangement, Anionic Si → C Alkyl Rearrangement, and Claisen–Schmidt Condensation

A highly efficient one-pot procedure was developed for the synthesis of various 2′-hydroxychalcones from phenyl diethylcarbamate, featuring consecutive Snieckus–Fries rearrangement, anionic Si → C alkyl rearrangement, and Claisen–Schmidt condensation in a single operation. The applicability of this protocol was demonstrated by the highly efficient synthesis of the anti-inflammatory natural product lonchocarpin. The mechanism insight is also provided.