Asymmetric synthesis of 9-alkyl tetrahydroxanthenones via tandem asymmetric Michael/cyclization promoted by chiral phosphoric acid

Org Biomol Chem. 2021 Jan 21;19(2):348-354. doi: 10.1039/d0ob02140g.

Abstract

A tandem asymmetric Michael-addition/cyclization of cyclic 1,3-dicarbonyl compounds to β,γ-unsaturated α-ketoesters catalyzed by chiral phosphoric acid is presented. This protocol provides a facile approach for the construction of enantioenriched 9-alkyl tetrahydroxanthenones, an ubiquitous framework found in a number of natural products and pharmaceutical molecules, in high yields with good to high enantioselectivities.

Publication types

  • Research Support, Non-U.S. Gov't