Synthesis of an Ellagitannin Component, the Macaranoyl Group with a Tetra- ortho-Substituted Diaryl Ether Structure

Org Lett. 2020 Sep 4;22(17):6729-6733. doi: 10.1021/acs.orglett.0c02066. Epub 2020 Aug 26.

Abstract

Herein, a practical synthesis of the macaranoyl group contained in ellagitannins, i.e., a C-O digallate structure with a tetra-ortho-substituted diaryl ether bond, is described. The methodology involved an oxa-Michael addition/elimination reaction between a brominated ortho-quinone monoketal and a phenol with a hexahydroxydiphenoyl moiety in the presence of 18-crown-6 under dark conditions, followed by reductive aromatization. The existence of rotamers originating from the constructed ether moiety is discussed as well.

Publication types

  • Research Support, Non-U.S. Gov't