Phenyl chloroformate → 1,1-dimethylethyl(1R,cis)2,2-dimethyl-3-[3-oxo-3-phenoxy-1-propynyl]-cyclopropane-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of 25 g of 1,1-dimethylethyl (1R,cis) 2,2-dimethyl-3-(2', 2'-dibromovinyl)-cyclopropane-carboxylate in 250 ml of tetrahydrofuran was admixed with 48 ml of a 20% solution of butyllithium in cyclohexane with stirring at -65° C. and the mixture was stirred for one hour at -65° C. 9.6 ml of phenyl chloroformate were added to mixture which was then stirred at -65° C. for one hour. The temperature was allowed to return to room temperature while the stirring was maintained and the mixture was poured into a saturated aqueous solution of monosodium phosphate. The mixture was extracted with ether and the ether phase was washed with water and dried. The 24.6 g of oil residue was chromatographed over silica gel and was eluted with a 9-1 cyclohexane-ethyl acetate mixture to obtain 14.4 g of 1,1-dimethylethyl (1R,cis) 2,2-dimethyl-3-[3-oxo-3-phenoxy-1-propynyl]-cyclopropane-carboxylate.

Provenance & Evidence