Enantiospecific synthesis of substituted bicyclo[2.1.1]hexane-1-carboxylic acid and esters

Article abstract of DOI:10.1016/S0957-4166(00)80096-8

The base promoted ring contraction of the readily accessible homochiral 2-oxo-1-norbornyl triflates 3 in 60% ethanol takes place with formation of bicyclo[2.1.1]hexane (4a), (+)- or (-)-7,7-dimethyl-bicyclo[2.1.1]hexan-1-carboxylic acids (4c or 4b) and the corresponding ethyl esters in good yields.