反应详情

Into a 100 ml round bottomed flask equipped with magnetic stirring was added 4.5 g (25 mmol) of 1-(α,α-dimethylbenzyl)-1-chloroethylene, 25 g (100 mmol) of bromoform, 27 g of methylene chloride, 0.37 g of N,N′-dibenzyl-N,N,N′N′-tetramethylethylenediammonium dibromide, and 12.4 g (100 mmol) of 45% aqueous KOH. Rapid stirring overnight gave a 20% conversion to the desired cyclopropane. Washing the aqueous layer with water and resubmitting with fresh bromoform, catalyst, and KOH overnight gave further conversion. A third submission was deemed adequate. The aqueous washed organic layer was evaporated in vacuo and chromatographed on silica gel using 2% diethyl ether in hexane yielding 4.2 g of 1-(α,α-dimethylbenzyl)-1-chloro-2,2-dibromocyclopropane.

1. customInto a 100 ml round bottomed flask equipped
2. stirringRapid stirring overnight