Synthesis of Fluorogypsetin and Fluorobrevianamide E by a Novel Fluorination–Cyclization of cyclo-L-Trp-L-AAs This work was supported by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture, Japan. N.S. wishes to thank the Novartis Foundation (Japan) for the Promotion of Science for support. We thank Prof. Yoshio Takeuchi very much for generously sharing his facilities, for very kind encouragement and for giving us the opportunity to study in the field of fluorine chemistry. We also thank F-TECH INC. for a gift of FP-T300.

Abstract

Fluoro-isosteres of natural products containing hexahydropyrazino[1′,2′-1,5]pyrrolo[2,3-b]indole-1,4-dione moieties are readily prepared by FP-T300-mediated fluorination–cyclization of cyclo-Trp-AAs (Trp=tryptophan, AA=amino acid). Isosteres 1 b and 2 b of gypsetin (1 a) and brevianamide E (2 a), respectively, were thus synthesized. Supporting information for this article is available on the WWW under http://www.angewandte.com or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.