The high versatility of 1-phenylsulfenyl- or 1-phenylsulfonyl-cyclopropylketones has been exploited for the regioselective synthesis of trans-2,3-disubstituted cyclobutanones, 2,4,5-trisubstituted 3,6-dihydro-2H-pyrans and cis-2-alkyl- or cis-2-aryl-cyclopropylphenylsulfones.