Citation: Sj. Brickner et al., N-ACYL 3-ALKYLIDENYL AZETIDIN-2-ONES AND 3-ALKYL AZETIDIN-2-ONES - A NEW CLASS OF MONOCYCLIC BETA-LACTAM ANTIBACTERIAL AGENTS .2. SYNTHESISANDST RUCTURE-ACTIVITY RELATIONSHIPS OF HETEROATOM SUBSTITUTED 3-ISOPROPYLIDENE A ND 3-ISOPROPYL ANALOGS, Bioorganic & medicinal chemistry letters, 3(11), 1993, pp. 2241-2246