Synthesis of Δ3-1-Methylene-1-carbacephems

Article abstract of DOI:10.1021/jm00155a013

The total synthesis of (+/-)-1-methylene-2,2-dimethyl-7-amino-1-carbacephem-4-carboxylic acid (1) is described.The reaction scheme was essentially that described by Christensen et al. for the synthesis of (+/-)-1-carbacephems.In vitro antibacterial activities of the 7-phenoxyacetyl and 7-D-α-phenylglycyl derivatives of 1 were compared with those of 7-(phenoxyacetamido)desacetoxycephalosporanic acid and cefalexin.Derivatives of 1 were 2-4 times less active against most of the sensitive organisms than the corresponding 7-aminodesacetoxycephalosporanic acid analogues.The activity of the 7-D-α-phenylglycyl derivative of 1 however was about 20 times lower than that of cefalexin when measured against Staphylococcus aureus ATCC 6538P.