Beta-lactamase inhibiting 2-beta-substituted-2-alpha-methyl-(5R)penam-3-alpha-carboxylic acid 1,1-dioxides and esters thereof, wherein the 2-beta-substituent is cyano, acetyl, alkoxycarbonyl, omegahydroxyalkoxycarbonyl, carbalkoxymethoxycarbonyl or dialkylaminocarbonyl; intermediates therefor wherein the 2-beta-substituent is carboxy, chlorocarbonyl or aminocarbonyl; methods for their preparation and use as beta-lactamase inhibitors.
                            β-内酰胺酶抑制剂2-β-取代-2-α-甲基-(5R)青霉烷-3-α-
羧酸1,1-二氧化物及其酯,其中2-β-取代基为
氰基、乙酰基、烷氧羰基、ω-羟基烷氧羰基、羰基烷氧甲氧羰基或二烷基
氨基羰基;其中间体,其中2-β-取代基为羧基、
氯羰基或
氨基羰基;其制备方法和用作β-内酰胺酶抑制剂的用途。