我们报告了简明的和无保护基团的对映体F和H的对映选择性总合成。鉴于喹唑啉酮生物碱的类似物在药物研究和发现中极为重要,因此有四种生物活性喹唑啉酮苯二氮卓生物碱的类似物,包括脱甲氧基环丁啶H(12)和N-去甲基苯并丙氨酸A(13)已合成。该方法基于酰亚胺与邻硝基苯甲酰亚胺的低价钛促进的分子内还原偶联,在温和条件下可生成喹唑啉代[3,2- a ] [1,4]苯并二氮杂pine。此外,七环脱水紫精素E(16)是通过NCS介导的脱水环化反应从阿斯匹林菌素C合成的。
Total synthesis of asperlicin C, circumdatin F, demethylbenzomalvin A, demethoxycircumdatin H, sclerotigenin, and other fused quinazolinones
作者:Ming-Chung Tseng、Huei-Yun Yang、Yen-Ho Chu
DOI:10.1039/b910545j
日期:——
Using scandium triflate and microwaves, the direct double dehydrocyclization of anthranilate-containing tripeptides was achieved, affording the total syntheses of (i) quinazolino[3,2-a]benzodiazepinediones (1a–f), (ii) diazepino[2,1-b]quinazolinediones (2a–e), and (iii) pyrazino[2,1-b]quinazolinediones (3a–e) with good overall isolated yields (23–43%, 37–47% and 31–56%, respectively). Among the quinazolino[3,2-a]benzodiazepinediones synthesized, 1a (sclerotigenin), 1b (circumdatin F), and 1f (asperlicin C) are natural products.
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 circumdatinF (1a), sclerotigenin (1b), and asperlicin C (1c), were achieved with good overall isolated yields (23-62%).