Carba-Methylephedrine and Carba-pseudo-Methylephedrine as Tools for Probing the Role of the Nitrogen Atom of Chiral Amino Alcohols in Asymmetric Synthesis
Chiral Alcoholates in Asymmetric Synthesis: A Renewal in the Search for Chiral Bases
摘要:
Chiral alcoholates are efficient reagents to afford in optically pure form the cyclic acetal 1, thus demonstrating the potential of this class of homochiral bases.
The use of chiral alkoxides obtained from ephedrines for enantioselective proton abstraction is described in full. These reagents allow the practical obtention of axially dissymmetric 1,3-dioxanes via highly enantioselective dehydrohalogenation reactions. The conditions for a catalytic use of these chiral alkoxides are defined.
First Catalytic Enantioselective Proton Abstraction Using Chiral Alkoxides