Routes from 1,1-cycloalkanedicarboxylic acids to geminal bis(polyfluoromethyl) substituted carbocycles

1-Fluoroformyl-1-(trifluoromethyl)cycloalkanes (1), prepared by treatment of 1,1-cycloalkane-dicarboxylic acids with SF4, were efficiently reduced to 1-hydroxymethyl-1-(trifluoromethyl)-cycloalkanes (2). Routes for the conversion of alcohols 2 to 1-methyl-1-(trifluoromethyl)cycloalkanes (4), 1-fluoromethyl-1-(trifluoromethyl)cycloalkanes (6) and 1-difluoromethyl-1-(trifluoromethyl)cycloalkanes (8), via iodides 3, triflates 5 and aldehydes 7, respectively, were investigated.