Synthesis 2019; 51(07): 1611-1622
DOI: 10.1055/s-0037-1610673
paper
© Georg Thieme Verlag Stuttgart · New York

A Facile Synthetic Approach to Nonracemic Substituted Pyrrolo-allocolchicinoids Starting from Natural Colchicine

Ekaterina S. Shchegravina
a   Department of Organic Chemistry, Nizhny Novgorod State University, 23 Gagarin Avenue, 603950 Nizhny Novgorod, Russian Federation   Email: afnn@rambler.ru
,
Elena V. Svirshchevskaya
b   Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry RAS, 16/10 Miklukho-Maklaya Street, 117997 Moscow, Russian Federation
,
Hans-Günther Schmalz
c   Department of Chemistry, University of Cologne, Greinstrasse 4, 50939 Cologne, Germany
,
a   Department of Organic Chemistry, Nizhny Novgorod State University, 23 Gagarin Avenue, 603950 Nizhny Novgorod, Russian Federation   Email: afnn@rambler.ru
› Author Affiliations
T This work was supported by the Russian Science Foundation (Project 16-13-10248).
Further Information

Publication History

Received: 28 October 2018

Accepted after revision: 05 November 2018

Publication Date:
13 December 2018 (online)


Abstract

A six-step semisynthetic approach towards chiral nonracemic pyrrolo-allocolchicinoids starting from naturally occurring colchicine was developed. The synthetic scheme includes an electrocyclic tropolone ring contraction to afford allocolchicinic acid followed by the Curtius reaction, giving the corresponding aniline. The Sandmeyer reaction and copper-mediated hydrazination gave hydrazine-substituted allocolchicine. This was introduced into the Fischer indole synthesis, affording libraries of regioisomeric indole-based allocolchicine congeners.

Supporting Information