General and versatile entry to 4, 5-fused polycyclic imidazolones systems. Use of the tandem transposition/π-cyclization of N-acyliminium species

A Pesquet, A Daïch, L Van Hijfte

Index: Pesquet, Anthony; Daich, Adam; Van Hijfte, Luc Journal of Organic Chemistry, 2006 , vol. 71, # 14 p. 5303 - 5311

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Citation Number: 30

Abstract

A simple and efficient methodology for the synthesis of 4, 5-fused imidazolidin-2-ones from bicyclic and tricyclic ketones in a four-step sequence was described, by successive spirohydantoin Bucherer-Berg formation, mono-and dialkylation of the nitrogen atom of the hydantoin ring, regioselective reduction of one carbonyl function, and cationic cyclization associated with ring expansion. The key step of this sequential reaction was based on a ...