Aspidospermidine and Its Simple Derivatives

Almost two decades after the first synthesis of aspidospermine, the Stork route still attracts attention, and a new preparation of Stork s racemic 

Reagems I, N2CH.CO.CX)2B, Cu. Ngl H, HBF4, HgO Hi, CHgNz iv, tryplamine. AcOH, MeOH v, NaBHaCN, AcOH, MeOH vl, MaSOzO, NEta, Ct Clz vH, MeOCHzCHzOMe, heat, 18 houis viii, MeOH, DcMwex I-X2, as peichlor ix, KOH, MeOH x, U, NHa. 

Meyer s route to the tricyclic ketone takes advantage of an original method for the preparation of asymmetric 4-substituted cyclohexenone derivatives (288). The asymmetry was ensured by use of the bicyclic 

Reagents i, MeAiClz, CHas, 0°C ii, NHzOH.HQ ill. BHa, py, HQ iv. (CICH2C0)20. NBa v. CKXIgMe. NEta vl, flash vacuum thermolysis vll, oxalic acid vlli, Ha, Rh, EtOAc lx, KOBu, PhH. 

Two further syntheses of aspidospermidine have been contributed by the Wenkert group. Both use as starting material the pentacyclic ketolactam 493, which was readily prepared from indoleacetic anhydride and 3-acetyl- 

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