leuconoxine and rhazinilam

Inspired by their potential biosynthesis, we have developed divergent total syntheses of seven monoterpene indole alkaloids including mersicarpine, leuconodines B and D, leuconoxine, melodinine E, leuconolam, and rhazinilam, and one unnatural analogue with an unprecedented structural skeleton. The key steps involve a Witkop-Winterfeldt oxidative indole cleavage followed by transannular cyclization. The transannular cyclization product was then converted to the corresponding structural skeletons by pairing its functional groups into different reaction modes.

Topics: Alkaloids; Azepines; Cyclization; Indole Alkaloids; Indolizines; Lactams; Molecular Structure; Oxidation-Reduction; Secologanin Tryptamine Alkaloids; Stereoisomerism