With ammonium acetate as catalyst, three-component ‘one-pot’ reaction of β-keto perfluoroalkanesulfones, aldehydes, and vinyl ethers proceeded smoothly and afforded tetrasubstituted 2,3-dihydropyrans in moderate to excellent yields. Both aromatic and aliphatic aldehydes, as well as cyclic vinyl ether are compatible with this methodology. All dihydropyran products were obtained as cis- and trans-diastereomeric mixtures. The relative configurations were established by comparing the coupling constants of anomeric protons of both isomers and confirmed by single-crystal X-ray diffraction analysis.