PROCESS FOR PREPARING VINCADIFFORMIN AND DERIVATIVES THEREOF

摘要

The process comprises a) condensing dimethyl 4-ethyl-4-formyl pimelate with an oxidised tryptamine deriv. e.g. 2-hydroxy-tryptamine to form an oxindolic lactam ester b) the oxindolic lactam-ester is reacted with a Meerween reagent to form the imino-ether c) the imino-ether is reacted with a strong base e.g. NaH to form 3-oxo-vincadyfformine d) this is reacted with PS5 to form 3-thio-vincadifformine e) treatment with Raney nickel yields. Vincadifformine f) heating of the vincadifformine with a mineral acid forms 1, 2-dehdyro-aspidospermidine. 3-Oxo-1,2-dehydro-aspidospermid ine may be obtained by heating 3-oxo-vincadifformine with a mineral acid or by dehydration of oxendolic lactam ester with polyphosphoric acid. Substd. cpds containing =2 hydroxy or alkoxy gps. in the 9 10,11 or 12 positions are also prepd. by the process.