Abstract
Racemic carbapenem antibiotics having a 1-(hydroxymethyl) ethylidene side-chain at C-6 [dl-asparenomycins A (54), B (37), C (53) and related compounds, 55, 56, 38, 59 and 45] were synthesized starting from the common intermediates 9a and 9b, and their antibacterial activities were examined. The synthesis involves transformation of a cyclic carbonate group into the 1-(hydroxymethyl) ethylidene moiety with a catalytic amount of 1, 8-diazabicyclo [5. 4. 0] undec-7-ene (DBU) in an appropriate solvent, and deblocking of the p-methoxybenzyl ester group by the AlCl3-anisole method.
