Synthesis of Naphthopyrans via Formal (3+3)-Annulation of Propargylic (Aza)- para-Quinone Methides with Naphthols

J Org Chem. 2020 Oct 16;85(20):13306-13316. doi: 10.1021/acs.joc.0c01791. Epub 2020 Oct 7.

Abstract

Herein, we report an efficient Brønsted acid-catalyzed formal (3+3)-annulation of (aza)-para-quinone methides generated in situ from propargylic alcohols with naphthol derivatives, which involves a 1,8-conjugate addition/6-endo annulation process. This protocol provides an effective method for preparing important functionalized pyranocoumarins under mild conditions.

Publication types

  • Research Support, Non-U.S. Gov't