Toluene → alpha-Cypermethrin 1-Epimeric Mixture

Participants

Reaction Steps

Cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (22 g, 0.105 M) was added to a solution of an inorganic base in water (50 ml). Toluene (100 ml), tetra-n-butylammonium bromide (1.6 g, 5 mole % based on the cyclopropane carboxylic acid) and alpha-cyano-3-phenoxybenzyl p-toluenesulphonate (37.9 g, 0.1 M) were added to the stirred mixture which was then heated at 40°-45° C. for 24 hours. The reaction mixture was then treated as in Example 1 to yield cis-alpha-cyano-3-phenoxybenzyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate as a pale amber oil containing less than 1% trans-isomers.

Provenance & Evidence