作者:Dieter Enders、Bert Nolte、Gerhard Raabe、Jan Runsink
DOI:10.1016/s0957-4166(02)00066-6
日期:2002.3
The first asymmetric synthesis of the conium alkaloid (-)-alpha-conhydrine is reported. Starting from a protected glycol aldehyde hydrazone as chiral precusor, a short route based on our alpha-alkylation/1,2-addition methodology has been developed. After cleavage of the auxiliary and simultaneous deprotection, the concluding ring closure is accomplished under reductive amination conditions. The title compound is obtained in moderate overall yield and in excellent diastereo- and enantiomeric excess (d.e., e.e. >96%). Single-crystal X-ray crystallography as well as H-1 NMR NOE experiments confirm the expected relative and absolute (2R,7S)-configuration of the product. (C) 2002 Elsevier Science Ltd. All rights reserved.