Isopenicillins, processes for their preparation, and compositions containing them.

摘要

Isopenicillins of the formula
<CHEM>
in which
R is acylamino, azido, or amino; and
M is hydrogen, a pharmaceutically acceptable cation, or a removable carboxylic acid protecting ester, can be prepared by ring-closing an appropriately 3-substituted-4- halomethyl beta -lactam of the formula
<CHEM>
in which
R min is acylamino or azido;
and when a compound (1) is required, in which R is amino, a protecting acyl group of an acylamino group R min is removed. Compound I show antibacterial activity against gram positive and gram negative organisms.