The phenylsulfonyl-substituted vinylic epoxide 1 was allowed to react with
BF3. OEt2 and various aromatics. A highly regioselective but moderately ste
reoselective mono-Friedel-Crafts reaction occurred which led to products 2
(Table 1). The fluorine-containing compounds 3a-b and 4 were obtained as si
de products.