Abstract: An objective of the present invention is to provide carbapenem derivatives which have strong antibiotic activity also against MRSA, PRSP, Influenzavirus, and ?-lactamase producing bacteria and are stable to DHP-1. The carbapenem derivatives according to the present invention are compounds represented by formulae (I) and (II) or pharmaceutically acceptable salts thereof: wherein R1 represents H or methyl, R2 and R3 each independently represent H; halogen; substituted or unsubstituted alkyl; cycloalkyl; substituted or unsubstituted alkylcarbonyl; carbamoyl; substituted or unsubstituted aryl; substituted or unsubstituted alkylthio; morpholinyl; alkylsulfonyl; or formyl, n is 0 (zero) to 4, and Hy represents a substituted or unsubstituted monocyclic or bicyclic heterocyclic group.

Abstract: An 1-N-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin of the formula: ##STR1## wherein R is a hydrogen atom or .beta.-D-ribofuranosyl group of the formula ##STR2## and R.sub.3 is hydroxyl, amino-NH.sub.2 or acylamino group --NHR.sub.4 in which R.sub.4 is an acyl group, and n is a whole number of 1 to 4, may be produced by subjecting the corresponding O-((S)-.alpha.-substituted-.omega.-aminoacyl)-neamine or -ribostamycin of the formula ##STR3## or its hydroxyl-masked and amino-masked form, to the action of a basic medium to produce an acyl-migration product of the formula: ##STR4## and, optionally converting the amino-masking groups into hydrogen atoms and also the hydroxyl-masking group into hydrogen atom in a known manner if said amino-masking groups and said hydroxyl-masking groups are present in the acyl-migration product. The 1-N-((S)-.alpha.-substituted-.omega.