Total Syntheses of the Metabolites of Schizandrin.

Abstract The total syntheses of the metabolites of schizandrin were achieved. The tetracyclic lactone intermediates (13a–e) were prepared in optically pure form by the oxidative coupling reaction of the corresponding 3-benzyl-1-benzylidenebutyrolactones. Mukaiyama hydration of 13b afforded hydroxylactone ( 14 ), which was converted into SZ-M3 (4). The introduction of C6,7-diol moiety, which is common to the metabolites ( 4–11 ), was carried out by the successive double bond migration to 15a–e , lactone ring reduction to the allylic diols ( 32a–e ), and glycol formation. Then, reduction of the mesylates 33 completed the syntheses of the metabolites.