Aryllead triacetates as synthons for the synthesis of biflavonoids. Part 1. Synthesis and reactivity of a flavanonyllead triacetate

Abstract

The 8-triacetoxyplumbylflavane derivative 11 was prepared in 4 steps in 28% overall yield from 4′,5,7-flavanone. It reacted with the benzofuranone ally β-keto ester 12 to yield a 8-(benzofuran-2yl)flavanone 13 in 66%. Removal of the allyl ester group and cleavage of the dioxolane ring afforded the 8-(3-oxobenzofuran-2-yl)flavanone. This reaction shows that complex polyfunctional aryllead triacetates can be made and selectively coupled with activated ketones.