Metal-Catalyzed Oxa-[4+2] Cyclizations of Quinone Methides with Alkynyl Benzyl Alcohols

J Org Chem. 2018 Nov 16;83(22):13861-13873. doi: 10.1021/acs.joc.8b02186. Epub 2018 Nov 1.

Abstract

An oxa-[4+2] cyclization of quinone methides with alkynyl benzyl alcohols has been realized in the presence of a metal catalyst, and the reaction afforded spiroacetal products in overall high yields (up to 99%) and good diastereoselectivities (up to >95:5 dr). By carrying out the reaction under gold catalysis and utilizing alkynyl benzyl alcohols as electron-rich reaction partners, this approach provides a useful strategy for settling the challenges in oxa-[4+2] cyclization of para-quinone methide derivatives. This reaction serves as a good example for metal-catalyzed oxa-[4+2] cyclizations of quinone methides. In addition, it also offers a useful method for the construction of spiroacetal skeletons.

Publication types

  • Research Support, Non-U.S. Gov't