The Formal Total Synthesis of (±)-Strychnine via a Cobalt-Mediated [2 + 2 + 2]Cycloaddition
作者:Michael J. Eichberg、Rosa L. Dorta、Kai Lamottke、K. Peter C. Vollhardt
DOI:10.1021/ol006131m
日期:2000.8.1
A short, highly convergent totalsynthesis of racemic isostrychnine, and thus strychnine, has been completed. The route involves 14 steps in the longest linear sequence and is highlighted by a cobalt-mediated [2 + 2 + 2]cycloaddition of an alkynylindole nucleus to acetylene.
Approaches to the Synthesis of (±)-Strychnine via the Cobalt-Mediated [2 + 2 + 2] Cycloaddition: Rapid Assembly of a Classic Framework
作者:Michael J. Eichberg、Rosa L. Dorta、Douglas B. Grotjahn、Kai Lamottke、Martin Schmidt、K. Peter C. Vollhardt
DOI:10.1021/ja016333t
日期:2001.9.1
Five synthetic approaches to racemic strychnine (1), with the cobalt-mediated [2 + 2 + 2] cycloaddition of alkynes to indoles as the key step, are described. These include the generation and attempted cyclization of macrocycle 8 and the synthesis of dihydrocarbazoles 15, 22, and 26 and their elaboration to pentacyclic structures via a conjugate addition, dipolarcycloaddition, and propellane-to-spirofused