Biomimetic Total Synthesis of Dispirocochlearoids A-C and Related Ganoderma Meroterpenoid Dimers.

The first total synthesis of the anti-inflammatory Ganoderma meroterpenoid dimers dispirocochlearoids A-C, along with five of their diastereomers─potential unreported natural products─has been accomplished using a convergent strategy that leveraged common intermediates derived from dayaolingzhiol M. The synthesis features several key steps: a hetero-Diels-Alder reaction, a hydrolysis/double-bond migration cascade to assemble the D/E-bicyclic core, and a condensation/intramolecular aldol/lactonization cascade that constructs the final B/C-bicyclic system of dispirocochlearoids A-C.