TOTAL SYNTHESES OF THE METABOLITES OF SCHIZANDRIN

The total syntheses of the metabolites of schizandrin were achieved. T he tetracyclic lactone intermediates (13a-e) were prepared in opticall y pure form by the oxidative coupling reaction of the corresponding 3- benzyl-2-benzylidenebutyrolactones. Mukaiyama hydration of 13b afforde d hydroxylactone (14), which was converted into SZ-M3 (4). The introdu ction 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, lact one ring reduction to the allylic diols (32a-e), and glycol formation. Then, reduction of the mesylates 33 completed the syntheses of the me tabolites.