The Z-enoate assisted, Meyer–Schuster rearrangement cascade: unconventional synthesis of α-arylenone esters

Abstract

Brønsted acid promoted nucleophilation of propargylic alcohols during the Meyer–Schuster rearrangement (M–S) has been introduced. A novel concept of reverse polarization of the M–S intermediate allenyl cation has been realized by employing a cis-enoate assisted strategy. This idea is well demonstrated by the metal free synthesis of complex, highly functionalized cyclic as well as acyclic α-arylenones. The synthetic importance of the derived products was highlighted by the efficient conversion to biologically relevant molecules such as pyrazoles and 4,5-seco-abietane.