Stereoselective preparation of the ABCD tetracycle of the 20-methyl analogue of aspidospermidine and related alkaloids
作者:Anahi Urrutia、J.Gonzalo Rodríguez
DOI:10.1016/s0040-4039(98)00710-2
日期:1998.6
The natural cis[ABCD] tetracycle of the 20-methyl analogue of aspidospermidine has been synthesised, starting from the 4,4-ethylenedioxy-1-cyclohexanone. This, was transformed into 3-methyl-3-(3'-nitropropyl)-1,2,3,4-tetrahydrocarbazol-4-one. Two key synthetic steps permits the construction of the D ring: i) the one pot nickel boride catalyst to the imine tetracycle in excellent yield; and ii) the stereoselective reduction of this imine to the natural cis D ring junction in good yield. (C) 1998 Elsevier Science Ltd. All rights reserved.