First total synthesis of (±)-2,3,2″,3″-tetrahydroochnaflavone

Abstract

The first total synthesis of (±)-2,3,2″,3″-tetrahydroochnaflavone has been achieved, which was isolated from the leaf of quintinia. The target molecular is consisting of naringenin and eriodictyol moieties, which was synthesized using 2,4,6-trihydroxyacetophenone and 4-hydroxybenzaldehyde as starting materials. The key steps in the synthesis of 2,3,2″,3″-tetrahydroochnaflavone were the formation of a diaryl ether and cyclization of an ether-linked bichalcone to assemble the dihydroflavone, and the key synthetic intermediates are detailed.