Tin triflate-mediated total synthesis of circumdatin F, sclerotigenin, asperlicin C, and other quinazolino[3,2-a][1,4]benzodiazepines†
Ming-Chung Tseng,Chi-Yu Lai,Yu-Wan Chu,Yen-Ho Chu
Chemical Communications Pub Date : 11/19/2008 00:00:00 , DOI:10.1039/B813880J
Abstract

Using tin triflate, as an effective Lewis acid, and microwaves, direct double 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 productscircumdatin F (1a), sclerotigenin (1b), and asperlicin C (1c), were achieved with good overall isolated yields (23–62%).

Graphical abstract: Tin triflate-mediated total synthesis of circumdatin F, sclerotigenin, asperlicin C, and other quinazolino[3,2-a][1,4]benzodiazepines