NOVEL ANATIBIOTIC PENEM DERIVATIVES AND THEIR PREPARATION

(5R,6S)-6((1R)-1-hydroxyethyl)-2-((5R)-5-oxazolidinonyl)-3-carboxyl-2-penem derivatives(I; R= H atom, methyl, ethyl, phenyl, aryl ring compound substituted by oxygen, nitrogen or sulphur; R1= H or ester forming group hydrolyzed in a biomass, indanyl, phthalidyl, methoxymethyl, glycycloxymethyl, phenylglycycloxymethyl, etc.) were prepared. Thus, 250 mg (5R)-5-carboxyl-3-t-butyldiphenylsilyl oxazolidinone was dissolved at 0 deg.C in 150 ml dichloromethane, and added 27.1 ml 60 % sodium hydride, 0.06 ml pyridin at -30 deg.C, 0.05 ml thionyl chloride, reacted at room temperature for 2 hours. 0.56 g (3S,4R)-3-(1-(R)-t-butyldimethylsilyloxyethyl)-1-(1-(4-nitrobenzyloxy-carbonyl)-1-(triphenylphosphoranylidene)methyl)azetidin-2-one-4-thiolate was reacted with the reactant to give 430 mg (3S,4R)-3-(1-(R)-t- butyldimethylsilyloxyethyl)-4-((5R)-5-(3-t-butyldiphenylsilyloxazolidinonyl)carbothio)-1-(1-(4-nitrobenzyloxycarbonyl)-1-(triphenylphosphoranylidene)methyl)azetidinone.