Kiyoshi Yoshida

A synthetic road to the forest of Strychnos, Aspidosperma, Schizozygane and Eburnamine alkaloids by way of the novel photoisomerization

Abstract The novel photoisomerization of 1-acylindoles accompanied by a conversion of indole to indolenine afforded 3-acylindolenines, a so far unknown reactive species, as a major product. This reaction was thorougly investigated and applied with success to the total synthesis of Strychnos, Aspidosperma, Schizozygane and Eburnamine alkaloids through a versatile intermediate 9-membered ring system, synthesized in a one pot reaction by photolysis and the simultaneous ring enlargement.

Synthesis of dl-vincadifformine, dl-eburcine and dl-3-epieburcine. Introduction of methoxycarbonyl function to c(3)-position of aspidosperma skeleton

Abstract Vincadifformine ( 7 ), eburcine ( 15 ) and 3-epieburcine ( 16 ) in racemic forms have been synthesized from 1,2-dehydroaspidospermidine ( 3 ) by introduction of methoxycarbonyl group to C(3)-position of aspidosperma skeleton.