A Divergent Chiral-Pool Strategy for the Asymmetric Synthesis of Iridoid Monoterpenoids and the (+)-Dioxa-[5.5.5.6] Fenestrane Core of Asperaculin A

A chiral-pool-based divergent strategy enables asymmetric synthesis of iridoid monoterpenoids (+)-isoboonein, (-)-boschnialactone, (+)-scholarein A (putative structure), and the (+)-dioxa-[5.5.5.6] fenestrane core of asperaculin A. Our synthesis features a stereoselective intramolecular Pauson-Khand reaction (IPKR) on a chiral enyne ether as the pivotal step, along with other stereoselective synthetic manipulations. Strategic extension of a readily accessible enediyne ether-based chiral precursor further facilitated one-pot tandem IPKR-anchored, tidy access to the tetracyclic fenestrane core of asperaculin A.