A quick access to the spirotricyclic core analogue of mangicol A by a Rh(Ⅰ)-catalyzed tandem Pauson-Khand/[4+2] cycloaddition

摘要

Highly chemoselective and stereoselective tandem Pauson-Khand/ [4+2] cycloaddition leads to efficient construction of the spirotricyclic core analogue of mangicol A. Mangicol A, isolated by Fenical in 2000 from a marine fungal Fusarium heterosporum, represents a new type of sesterterpene polyols with an unprecedented spirotricyclic skeleton and a quaternary chiral carbon core. Mangicol A and other members of this family of natural products have shown antiinflammatory activity which indicates their potential in this therapeutic application. The challenging structure of mangicols and their medicinal potential have made this class of compounds attractive synthetic targets.