Tetrahedron letters

A simple, efficient access to functionalized pyrrolobenzazepines related to the ABC core of cephalotaxine

ER de Oliveira, F Dumas, J d'Angelo

Index: De Oliveira, Eduardo R.; Dumas, Francoise; D'Angelo, Jean Tetrahedron Letters, 1997 , vol. 38, # 21 p. 3723 - 3726

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Citation Number: 14

Abstract

Tetracyclic nitrile 19a and ester 19b, exhibiting the ABC core of cephalotaxine 1a, were prepared through KH-induced cyclization of thioimides 14a and 14b, respectively. This new ring-closure methodology proved to be particularly efficient: thus nitrile 19a was obtained in only 7 steps with a 17% overall yield from commercially available, inexpensive safrole 2.