Synthesis of [1] benzopyrano [4, 3-b] pyrrol-4 (1H)-ones from N (α)-(2-oxo-2H-1-benzopyran-4-yl) weinreb α-aminoamides

A Alberola, R Álvaro, AG Ortega, ML Sádaba…

Index: Alberola, Angel; Alvaro, Rocio; Ortega, Alfonso Gonzalez; Sadaba, M. Luisa; Sanudo, M. Carmen Tetrahedron, 1999 , vol. 55, # 46 p. 13211 - 13224

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Citation Number: 16

Abstract

N (α)-(2-Oxo-2H-1-benzopyran-4-yl) Weinreb-α-aminoamides were prepared from 4- chlorocoumarin and α-aminoacid derivatives. Their reaction with organometallic compounds (RLi or RMgBr) and subsequent cyclization of ketones thus obtained, give [1] benzopyrano [4, 3-b] pyrrol-4 (1H)-ones. Starting from proline derivatives, simultaneously with the pyranone-pyrrole fusion, we establish an interesting procedure for the formation of ...