Phosphine-Catalyzed [8 + 2]-Annulation of Heptafulvenes with Allenoates and Its Asymmetric Variant: Construction of Bicyclo[5.3.0]decane Scaffold.

In this paper, a phosphine-catalyzed [8 + 2]-annulation of heptafulvene with allenoates has been achieved under mild conditions, giving functionalized bicyclo[5.3.0]decane derivatives in moderate to excellent yields. Using chiral phosphine as the catalyst, optically active products were obtained in moderate to high yields with excellent enantioselectivities.