Abstract: Disclosed are diazabicyclo compounds of formula (I) ##STR1## in which R.sup.1 is a substituted or unsubstituted lower alkyl, lower alkenyl or lower alkynyl; R.sup.2 is a hydroxy; R.sup.3 is a lower alkoxycarbonyl; R.sup.4 and R.sup.7 are hydrogens or substituted or unsubstituted phenyl groups; R.sup.5 and R.sup.6 are hydrogens or lower alkyl groups; or pharmaceutically acceptable salts thereof, having cardioprotective activity. Also disclosed are methods of treating cardiovascular disease using a compound of formula (I) or pharmaceutically acceptable compositions comprising the compound of formula (I).

Abstract: An azetidin-2-one derivative represented by the following formula (I) ##STR1## wherein R.sup.1 represents a hydrogen atom, a lower alkyl group, an aryl group, an aralkyl group, a lower alkoxy group, aralkoxy group, a lower alkylthio group, an aralkylthio group, or a substituted amino group, R.sup.2 represents a hydrogen atom, a lower alkyl group, an aryl group or an aralkyl group, and R.sup.3 represents a hydrogen atom or a group of the formula ##STR2## in which R.sup.4 represents a hydrogen atom or a protective group for the hydroxyl group; and a process for production thereof.