Synthesis of pentacyclic 13-azadibenzo[a,de]anthracenes via anionic cascade ring closure

Jesper L Kristensen; Per Vedsø; Mikael Begtrup

doi:10.1021/jo0300340

Synthesis of pentacyclic 13-azadibenzo[a,de]anthracenes via anionic cascade ring closure

J Org Chem. 2003 May 16;68(10):4091-2. doi: 10.1021/jo0300340.

Authors

Jesper L Kristensen¹, Per Vedsø, Mikael Begtrup

Affiliation

¹ Department of Medicinal Chemistry, The Danish University of Pharmaceutical Sciences, Universitetsparken 2, 2100 Copenhagen, Denmark. jekr@dfh.dk

PMID: 12737598
DOI: 10.1021/jo0300340

Abstract

Bromine-lithium exchange using tert-butyllithium at -78 degrees C initiates a cascade process whereby either xanthone derivatives or pentacyclic 13-azadibenzo[a,de]anthracenes are produced in high yields. The reaction proceeds via a sequential intramolecular trapping of organolithium intermediates.