PROCESS FOR THE PREPARATION OF -SUBSTITUTED -CYANOMETHYL ALCOHOL ENANTIOMERS

摘要

The invention concerns a process for the preparation of an alpha -substituted- alpha -cyanomethyl alcohol enantiomer of formula I wherein the group R<1> is an alkenyl, alkynyl, aryl or heteroaryl group by reacting an aldehyde of formula II R<1>-CHO II with hydrogen cyanide in the presence of a cyclic dipeptide enantiomer at a temperature below ambient temperature. The process enables the preparation of compounds of formula I in high yield and high enantiomeric excess. The enantiomers of formula I may be used as intermediates for the preparation of chiral pyrethroids and chiral arylethanolamines. The invention also embraces cyclic dipeptide enantiomers, processes for the preparation of chiral pyrethroids and chiral arylethanolamines from alpha -substituted- alpha -cyanomethyl alcohol enantiomers of formula I and chiral pyrethroids and chiral ethanolamines and the chiral pyrethroids and chiral ethanolamines prepared thereby.