Boron trifluoride etherate → 8-Bromo-2,4-dioxo-bicyclo[3.2.2]non-8-ene-6-carboxylic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

4.2 ml of trimethylsilyl-diazomethane are added dropwise at a temperature of −10° C. to a solution of 1.91 g (7 mmol) of 5-bromo-7,8-dioxo-bicyclo[2.2.2]oct-5-ene-2-carboxylic acid methyl ester in 20 ml of dichloromethane and 0.089 ml (0.7 mmol) of boron trifluoride etherate. The cooling is removed and the reaction mixture is stirred for 4 hours at a temperature of 20° C. The reaction solution is then extracted with water, the organic phase is dried over sodium sulfate and concentrated by evaporation using a rotary evaporator, and the residue is purified by silica gel chromatography. An isomer of 8-bromo-2,4-dioxo-bicyclo[3.2.2]non-8-ene-6-carboxylic acid methyl ester is obtained.

Provenance & Evidence