Abstract: A dithioacetal carbapenem of the formula ##STR1## in which R.sup.1 is hydrogen or C.sub.1-6 alkyl;n is 0, 1 or 2;R.sup.3 is hydrogen or C.sub.1-6 alkyl;R.sup.2 isC.sub.1-6 alkyl,phenyl optionally substituted with cyano, --CO.sub.2 NH.sub.2, --CH.sub.2 OH, --CH.sub.2 NH.sub.2, --CONHNH.sub.2 or with up to 5 halogen atoms, C.sub.1-6 alkyl or C.sub.1-6 alkyloxy groups,phenylmethyl optionally substituted with up to 5 halogen atoms, C.sub.1-6 alkyl or C.sub.1-6 alkyloxy groups on the phenyl ring, ora radical represented by the formula--(CH.sub.2).sub.p --Xin which p is 0 or 1; X is five-membered aromatic heterocyclic ring containing up to 1 sulfur, 1 oxygen or 4 nitrogen atoms, optionally substituted with a C.sub.1-6 alkyl group, or six-membered aromatic heterocylic ring containing up to 4 nitrogen atoms, optionally substituted with a C.sub.1-6 alkyl group.or a non-toxic pharmaceutically acceptable salt, physiologically hydrolyzable ester or solvate thereof.

Abstract: The present invention relates to new 3-guanidinoalkyl-2-azetidinones of the formula ##STR1## wherein: U and W can be the same or different and are selected from the group consisting of hydrogen and an amino protecting group;n is 1 to 3;X is a member selected from the group consisting of hydrogen, trialkylsilyl, arylsulfonyl, amino substituted arylsulfonyl, alkylsulfonyl, arylaminocarbonyl, alkylcarbonyl and arylcarbonyl; andY is a member selected from the group consisting of hydrogen, arylalkenyl, arylalkyl, formyl, carboxy, alkoxycarbonyl, acyloxy, arylthio, arylsulfinyl, arylsulfonyl, alkylthio, alkylsulfinyl, alkylsulfonyl, arylaminocarbonyl, the radical ##STR2## in which R is hydrogen, alkyl or arylalkyl, and the radical ##STR3## in which m is 1 to 3 and R' is hydrogen or --CO.sub.2 R" wherein R" is hydrogen, alkyl or arylalkyl.The novel axetidinones of the present invention exhibit anti-thrombin and anti-trypsin activities and are thus useful in controlling blood coagulation and treating pancreatitis.