[reaction: see text] Chloral or its hydrate undergoes the carbon-carbon bond-formation reaction with various optically active imines in the absence of any additive, followed by hydrolysis, to produce the corresponding beta-trichloromethyl-beta-hydroxy ketones in good yields with high enantioselectivities. In addition, the products with higher ee values were obtained by a simple recrystallization process
Catalytic Asymmetric Formation of δ-Lactones by [4+2] Cycloaddition of Zwitterionic Dienolates Generated from α,β-Unsaturated Acid Chlorides
作者:Paolo S. Tiseni、René Peters
DOI:10.1002/anie.200700859
日期:2007.7.9
JPH09227441A
申请人:——
公开号:JPH09227441A
公开(公告)日:1997-09-02
Catalytic Asymmetric Formation of δ-Lactones from Unsaturated Acyl Halides
作者:Paolo S. Tiseni、René Peters
DOI:10.1002/chem.200902896
日期:2010.2.22
Previously unexplored enantiopure zwitterionic ammonium dienolates have been utilized in this work as reactive intermediates that act as diene components in hetero‐Diels–Alderreactions (HDAs) with aldehydes to produce optically active δ‐lactones, subunits of numerous bioactive products. The dienolates were generated in situ from E/Z mixtures of α,β‐unsaturated acid chlorides by use of a nucleophilic