Process for bicyclic beta-lactams.

摘要

1-Carbapenam-2-one-3-carboxylic acid and 1-carba-3-hydroxy-3-cephem-4-carboxylic acid and esters thereof are provided by a process comprising a rhodium C2-C10 carboxylate catalyzed cyclization of an ester of a 4-(1-alkoxy- or 1-substituted alkoxy)-2-oxo-4-azetidinyl)- alpha -diazo- beta -ketobutyric acid and an ester of a 5-(1-alkoxy- or 1-substituted alkoxy-2-oxo-4-azetidinyl)- alpha -diazo- beta -ketovaleric acid respectively. The process is carried out in an inert organic solvent at a temperature between about 15 DEG C and about 85 DEG C. The 1-carba bicyclic beta -lactams are intermediates for preparing antibiotics.