CATALYTIC ASYMMETRIC SYNTHESIS OF CYCLOPROPANECARBOXYLIC ACIDS, AN APPLICATION TO INSECTICIDES SYNTHESIS

摘要

Reaction of alkyl diazoacetate with an olefin in the presence of a chiral copper catalyst gives an optically active alkyl cyclopropanecarboxylate. This reaction was applied to the synthesis of pyrethroidal intermediates: 1R-trans-chrysanthemic acid (I), 1R-cis-permethrinic acid (II) and 1S-2,2-dimethylcyclopropanecarboxylic acid (III). An effective catalyst, copper complex of a chiral Schiff base, was prepared starting with an optically active α-amino acid. The catalyst gave the products of more than 90% e.e.