An Unusual Stereoselective Decarboxylation: A Key Reaction to an Important Intermediate of Carbapenem Antibiotics

Article abstract of DOI:10.1021/jo00131a010

The dramatic difference in reactivity of the two diastereomeric acid esters 4A and 4B during decarboxylation has been thoroughly investigated.The (R) isomer 4A underwent decarboxylation to provide a 94:6 mixture of 5A and 5B at 80 deg C in 5-6 h.Under the same conditions the (S) isomer 4B did not undergo decarboxylation and with further heating to 120 deg C gave mainly the ring-opened decomposition product 6 along with unidentified decomposition products.A mechanistic rationale for this unusual reactivity profile is provided.