Asymmetric Synthesis of Substituted Homotropinones from <i>N</i>-Sulfinyl β-Amino Ketone Ketals. (−)-Euphococcinine and (−)-Adaline

Abstract

Sulfinimine-derived N-sulfinyl β-amino ketone ketals on heating with NH4OAc:HOAc undergo a four-step intramolecular Mannich cyclization cascade reaction to give homotropinones, such as (−)-euphococcinine, in excellent yields as single isomers