Selective Bromochlorination of endo-1,4-Dibromotricyclo[5.2.1.0^2,6]deca-3,8-diene-5,10-dione 10-Ethylene Acetal at the Conjugated Carbon-Carbon Double Bond

Abstract

Exposure of (1) to bromine in thionyl chloride/ dimethylformamide produced (5), the result of regio- and stereo-selective addition of bromine chloride across the carbonyl-conjugated double bond. The structure of (5) was determined by X-ray crystallography, and its mode of formation is discussed in terms of the carbonyl attack mechanism.