Ninhydrin as a building block for yohimbanones, β-carbolines, and oxyprotoberberines
摘要:
Condensation of ninhydrin with tryptamide or tryptamine followed by Lewis acid-induced rearrangement provided yohimbanones that were readily converted to beta-carbolines via oxidative ring cleavage. The analogous condensation-rearrangement with 3,4-dimethoxyphenethylamine and ninhydrin afforded an oxyprotoberberine, which was further oxygenated at the 13a position. (c) 2006 Elsevier Ltd. All rights reserved.