cyclizations of bis(anthranilate)-containing tripeptide precursors to afford the total syntheses of 7-substituted quinazolino[3,2-a][1,4]benzodiazepinediones (1a-f), including natural products circumdatin F (1a), sclerotigenin (1b), and asperlicin C (1c), were achieved with good overall isolated yields (23-62%).
使用
三氟甲磺酸锡(作为有效的
路易斯酸)和微波,直接对含双(
邻氨基苯甲酸酯)的三肽前体进行双环化,以提供7-取代的
喹唑啉基[3,2-a] [1,4]苯并二氮杂二酮(1a -f),包括环丁
抑素F(1a),硬化素(1b)和曲霉菌素C(1c)的
天然产物,均具有良好的总体分离收率(23-62%)。