Total Synthesis of (-)-Xylogranatopyridine B via a Palladium-Catalyzed Oxidative Stannylation of Enones

We report a total synthesis of the pyridine-containing limonoid alkaloid (-)-xylogranatopyridine B in 11 steps from commercially available dihydrocarvone. The central pyridine ring was assembled by a Jate stage fragment coupling approach employing a modified Liebeskirid pyridine synthesis. One-fragment, was prepared by an allyl-palladium catalyzed oxidative enone beta-stannylation, in-which the key bimetallic beta-starinyt palladium etiolate intermediate undergoes a beta-hydrideelimination. This methodology also allowed introduction, of alkyl-and silyl groups to the beta-position of enones