Synthesis of Carbapenems with a Sulfonyl Group in the C-6 Side-Chain and Their Biological Activity.

A new type of 5, 6-cis-carbapenems (racemic) having a sulfonyl group in the C-6 side-chain were synthesized by employing the synthetic methodology reported in our previous papers, and an alternative stereocontrolled synthesis of these 5, 6-cis-carbapenems was achieved starting from 8-oxo-7-azabicyclo [4.2.0] oct-3-ene (14) via an intramolecular aldol condensation as the key step. Chiral 5, 6-cis-carbapenems were also synthesized from (1S, 6R) -8-oxo-7-azabicyclo [4.2.0] oct-3-ene (29), which was derived from cis-1, 2, 5, 6-tetrahydrophthalic anhydride. The carbapenems thus obtained proved to be highly stable to the mouse kidney homogenate, and most of them showed good antibacterial activity as well as potent β-lactamase inhibitory activity.