A Synthetic Entry to Ervatamine Alkaloids − Synthesis of (±)-6-Oxo-16-episilicine and (±)-6-Oxosilicine

Recent developments in the chemistry of dihydropyridines

“…Thus, treatment of dihydropyridines 11 with trichloroacetic acid anhydride (TCAA), followed by the baseinduced degradation of the trihalomethyl ketone, resulted in the formation of the methoxycarbonyl derivatives 12, which were further elaborated to accomplish the preparation of ervatamine alkaloids. 9 On the other hand, interaction of 11 with Eschenmoser's salt, and subsequent cyclization of the resulting iminium ion, afforded tetracycle 13 en route to the total synthesis of ervitsine (Scheme 3).…”

Generation and Intermolecular Reactions of 2-Indolylacyl Radicals

“…In particular, addition of nucleophilic acyl radicals 3 to alkenes provides a useful and practical method for the formation of carbon−carbon bonds leading to unsymmetrical ketones. In the context of our studies on the synthesis of 2-acylindole alkaloids, we are currently investigating the possibility that a variety of 2-acylindole compounds can be prepared through reactions of 2-indolylacyl radicals with appropriate acceptors. In this Letter we describe the generation of this type of radical from different precursors (phenyl selenoesters 1 , aldehydes 2 , and glyoxylic acids 3 , Scheme ) and their role in intermolecular reactions with alkenes and pyridines.…”

Formation of Cyclohepta[b]indole Scaffolds via Heck Cyclization: A Strategy for Structural Analogues of Ervatamine Group of Indole Alkaloid

“…Recently, a synthetic pathway for structural analogues of bis-indole alkaloids such as caulerpin has been reported . Although a number of approaches for the total synthesis of the aforesaid alkaloids have been revealed, synthesis of these scaffolds necessitates a generalized and viable procedure. In this paper, we are reporting a new synthetic approach for some cyclohepta­[ b ]­indoles that are structurally analogous to many natural alkaloids (Scheme ).…”