PROCESS FOR THE PREPARATION OF ONE OF A PAIR RACEMIC LSOMER IN CYHALOTHRIN ISOMER

摘要

A process for preparing a pair of mirror image isomers of mixture of formula (I) and (II) (wt. ratio (I):(II) is 1:1) comprises (a) mixing alpha-cyano-3-phenoxybenzyl, cis-3-(z-2-chloro3,3,3-trifluorprop-1- en-1-yl)-2,2-dimethylcyclopropane carboxylate with iso-propanol; (b) adding 0.5-5 mol% of tetra-N-butyl ammonium isoprofoxide to the mixt.; (c) cooling it to -20-5 deg.C; (d) adding 1 wt.% of mirror image isomer and crystalizing it by stirring at -20-5 deg.C. The mixture is useful as insectides.