The first totalsynthesis of the indole alkaloid mersicarpine is reported. Key steps include a beta-dicarbonyl radical cyclization, as well as an oxidation of the benzopyrrole moiety to establish the masked 1,2-dicarbonyl functionality. An X-ray crystal structure and discussion of the 1H NMR behavior of the natural product are also presented.
Expanding the Scope of Mn(OAc)<sub>3</sub>-Mediated Cyclizations: Synthesis of the Tetracyclic Core of Tronocarpine
作者:Jakob Magolan、Michael A. Kerr
DOI:10.1021/ol061698+
日期:2006.9.1
Pyrroles, indoles, and surprisingly, indolines, when equipped with a pendant malonyl group on the nitrogen atom, were effective substrates in a Mn(III)-mediated oxidative cyclization reaction, yielding the 1,2-annulated products in good to excellent yields. When indole acetonitrile was used as a substrate this method provided a rapid synthesis of a tetracyclic tronocarpine subunit.