Abstract The 3-O-and 5-O-(Z)-propenyl ethers derived from 1, 2-O-isopropylidene-α-D-xylo- and glucofuranoses, respectively, were attached to the Merrifield, MPPC and NCPSC resins using alkylsulfonyl linkers. The [2+ 2]-cycloaddition of chlorosulfonyl isocyanate to the polymer-bound vinyl ethers followed by the intramolecular alkylation of the β-lactam nitrogen led to the formation of mixtures of the corresponding diastereomeric oxacephams or ...