Affordable Access

Publisher Website

Regioselectivity of Pictet-Spengler Cyclization Reactions to Construct the Pentacyclic Frameworks of the Ecteinascidin-Saframycin Class of Tetrahydroisoquinoline Antitumor Antibiotics

Authors
Journal
Tetrahedron Letters
0040-4039
Publisher
Elsevier
Publication Date
Volume
48
Issue
21
Identifiers
DOI: 10.1016/j.tetlet.2007.03.113
Keywords
  • Article
Disciplines
  • Chemistry

Abstract

The regiochemical outcome of Pictet-Spengler cyclization reactions directed toward the preparation of the pentacyclic core of the ecteinascidin class of antitumor antibiotics has been investigated on two different phenolic substrates. In one substrate, the assistance of an incipient benzylamine group at C-4 is postulated to direct the cyclization in favor of the pentacyclic framework of ET-743, which bears a hydroxyl group at C-18. Conversely, cyclization of an alternative substrate lacking a heteroatom at C-4 favors the opposite regiochemical outcome, primarily affording an unnatural pentacyclic core bearing a hydroxyl group at C-16.

There are no comments yet on this publication. Be the first to share your thoughts.