In the course of our studies on the reaction of γ-halocarbanions, [8] we have observed that carbanion of 3-chloropropyl pentachlorophenyl sulfone in the reaction with aromatic aldehydes gave 1-aryl-4-chloro-1-butene products of Julia-Kocienski olefination, instead of expected 2-aryl-3-pentachlorophenylsulfonyl tetrahydrofuranes. [9] Obviously, in the initial aldol-type adducts oxygen anion adds to the electron-deficient aromatic ring, so the Smiles rearrangement ...
