Transformations of penicillins: new methods of formation and reactions of 6,6-disubstituted penams and 7,7-disubstituted cephems

Abstract

The reactions of penicillanate esters with ethyl or trichloroethyl N-chloro-N-sodiocarbamate gave 6α-ethoxyform-amido and 6α-trichloroethoxyformamido-6β-acylaminopenicillanates, respectively. The 6α-trichloroethoxyform-amido-group was transformed in certain penicillanates into a 6α-amino-group. 7β-Acylamino-7α-ethoxyform-amidodeacetoxycephalosporanates were formed from the appropriate 6,6-disubstituted penicillanate S-oxides. The reaction of the 6,6-disubstituted penicillanates with phosgene led to a 1-ethoxycarbonyl-2-oxo-3-phenoxy-acetyl-1,3-diazetidine-4-spiro-6′-penicillanate.