METHOD FOR PRODUCING OPTICALLY ACTIVE 2,3-DIHYDROFARNESAL
申请人:TAKASAGO INTERNATIONAL CORPORATION
公开号:US20150218072A1
公开(公告)日:2015-08-06
A method for producing an optically active 2,3-dihydrofarnesal of formula (1) is disclosed. The method includes subjecting β-farnesene f formula (2) to amination in the presence of a lithium salt of an amine to obtain (2E)-farnesyl allylamine of general formula (3); subjecting the (2E)-farnesyl allylamine to asymmetric isomerization to obtain an optically active farnesyl enamine of general formula (4); and subjecting the optically active farnesyl enamine to solvolysis:
Enantioselective Access to (−)-<i>Ambrox</i><sup>®</sup>Starting from<i>β</i>-Farnesene
作者:Christian Chapuis
DOI:10.1002/hlca.201300286
日期:2014.2
Starting from inexpensive (E)‐β‐farnesene (1), an eight‐step enantioselective synthesis of the olfactively precious Ambrox® ((−)‐2a) has been performed. The crucial step is the catalytic asymmetric isomerization of (2E,6E)‐N,N‐diethylfarnesylamine (3) to the corresponding enamine (−)‐(R,E)‐4a, applying Takasago's well‐known industrial methodology. The resulting dihydrofarnesal ((+)‐(R)‐5) (90% yield