2-[(R) Amino acid alkyl]penems

A compound represented by the formula ##STR12## wherein R' and R" are independently hydrogen, lower alkyl, lower alkenyl, phenyl, substituted phenyl wherein the substituents are one or more groups chosen from among chloro, bromo, fluoro, lower alkyl, hydroxy, nitro, amino, aminomethyl, lower monoalkylamino, lower dialkylamino, lower alkoxy and carboxy, heteroaryl of 5 to 7 ring atoms of which 3 to 6 are carbon atoms and the remaining ring atoms are nitrogen, sulfur or oxygen, or R'is hydrogen and R" is CH.sub.3 (CH.sub.2).sub.p CO-- or CH.sub.3 (CH.sub.2).sub.q SO.sub.2 --, wherein p is 0-16 and q is 1-17, or R', R" and the N to which they are attached form a group of the formula ##STR13## wherein X is hydrogen, lower alkyl or amino;

• n is 0 to 4;
• and
• the pharmaceutically acceptable salts thereof, in racemic or optically active form.