Convergent and rapid assembly of benzonaphthopyranone cores of chartreusin, chrymutasins and hayumicins

A new methodology for the rapid regiospecific synthesis of benzonaphthopyranones has been developed, on the basis of a tactical extension of the Hauser–Kraus annulation. The prowess of the methodology has been illustrated by a short synthesis of chartarin (22b) and a facile entry to the chrymutasin scaffold (26).