A ceph-3-emcarboxylic acid reacted with diphenylphosphoryl azide-toluene-t-butyl alcohol-triethylamine to give the 4a- and 4ß-t-butoxycarbonylceph-2-ems and a 4-t-butoxyformamidoceph-2-em. Interconversion studies on the 4a- and 4ß-esters were performed. Reaction in the presence of excess of sodium azide gave as the sole ß-lactam product a 4-t-butoxyformamidoceph-3-em.
|Number of pages||2|
|Journal||Journal of the Chemical Society, Perkin Transactions 1|
|Publication status||Published - 1979|