Stereoselective Solid-Phase Synthesis of β-Lactams-A Novel Cyclization/Cleavage Step towards 1-Oxacephams.

Despite the antibiotic activity and the attractiveness of β-lactams, the solid-phase synthesis of this class of compounds has been barely reported. Now the diastereoselective synthesis of the 1-oxacepham 2 from the resin-bound β-lactam derivative 1 has been achieved in five steps. The synthesis of 2 and other 1-oxacephams is attractive because all the reaction steps proceed in high yield, the purity of the product is high, and the reaction sequence is simple.