TOTAL SYNTHESES OF THE LIGNANS ISOLATED FROM SCHISANDRA CHINENSIS

Abstract The total syntheses of wuweizisu C ( 4 ), gomisin J ( 6 ), gomisin N (7), and γ-schizandrin ( 8 ) having natural configuration were accomplished in a stereoselective manner. The catalytic hydrogenation or the metal mediated 1,4-reduction of the tetracyclic lactones ( 12, 17, 22, 30 ) played the significant role for the stereoselective introduction of C6, C7 dimethyl moiety. Furthermore, the neighboring carbonyl group assisted regioselective demethylation of 5 was essential for the synthesis of 6 .