Chemical conversion of some natural oxindoles (pteropodine, isopteropodine and isorhynchophylline) into the corresponding indole alkaloids has been made by way of a sequence of reactions which include formation of iminoethers of the natural oxindoles with Meerwein's reagent, reduction of the iminoethers to 2,3-seco-indoles and cyclization of 2,3-seco-indoles to the desired natural indole alkaloids. Sodium
Enantioselective Syntheses of Heteroyohimbine Natural Products: A Unified Approach through Cooperative Catalysis
作者:Ashkaan Younai、Bi-Shun Zeng、Herbert Y. Meltzer、Karl A. Scheidt
DOI:10.1002/anie.201502011
日期:2015.6.1
biological activity, with alstonine being the major component of a plant‐based remedy to treat psychosis and other nervous system disorders. This work describes the enantioselective total syntheses of these naturalproducts with a cooperative hydrogen bonding/enamine‐catalyzed Michael addition as the key step.