A Biomimetic Approach to Quinazolino[3,2-d][1,4]benzodiazepine Ring System: The First Total Synthesis of Asperlicin D

Naim H. Al-Said*, Lina S. Al-Qaisi

Department of Applied Chemical Sciences, Jordan University of Science and Technology
P.O. Box 3030, Irbid 22110, Jordan, Fax: 962-2-7095014.
E-mail: naim@just.edu.jo

Lewis acid (MgCl2, ZnCl2) mediated cyclodehydration of a linear tripeptide comprised of three amino acid units in the order of anthranilic-anthranilic-glycine (C-terminal anthranoyl-anthranilate methyl ester) furnished the tricyclic quinazolino[3,2-d][1,4]benzodiazepine ring system found in various biologically active natural alkaloids. This methodology, implemented with a tripeptide encompassing the sequence of anthranilic-anthranilic-tryptophan methyl ester, furnish the first total synthesis of asperlicin D.

Key words: lewis acids, quinazolino[3,2-d][1,4]benzodiazepine, linear tripeptide, total synthesis, asperlicin D.