The Synthesis Of Penem And Key Intermediate Azetidinone

Penems show broad-spectrum antibacterial especiallyβ-lactamases. There was not cross resistance with otherβ-lactamases compound and only antibacterial to stillness bacterium.The structural core of penems molecules is a hybrid of penicillin and cephalosporin structures. Double bond was bring in penem chemical constitution to improve the reactivity ofβ-lactamases and heithgen antibacterial activity. We introduce theβ-lactamases antibiotic and research ang development of penems compounds. Discuss the azetidinone which medicament key intermediate synthesized.Azetidinone is the key chirality intermediate to synthesize penems and carpenems. Through analyse the synthesis route, we improve the rigor condition and increase the yield. (3R,4R)-4-Acetoxy-3-[(R)-1-(t-Butyl-dimethylsilyloxy)Ethyl]-2-Azetidinone was synthesized by diazotized and brominated of 6-APA followed by esterification ,deoxidize,cleavage and oxidation with an overall yield of about 35.88%.Researching the chemical constitution of penems, we know C-2 substituent is important to stabilize the penems structure. The antibacterial activity of ring derivates is better than acyclic derivates.We synthesized the (5S,6R)-2-parachlorophenyl-acid-6-((1R)- tert-Butyldimethylsilyl-oxyethyl)penem-3-carboxylic acid allyl ester. It was synthesized with azeditinone by substitution , acylation , and wittig. Thiocarboxylic acids was synthesized with phosphorus pentasulfide by sulfuration . The reaction product was not separated and used for next reaction . The end product was characterization.