152560-40-2

Upstream product

• 20887-95-0 N-(tert-Butyloxycarbonyl)-L-cysteine 
• 24424-99-5 di-tert-butyl dicarbonate 
• 152560-39-9 (3S,4R)-3-<(R)-1-tert-butyldimethylsilyloxyethyl>-4-<(R)-2-tert-butoxycarbonylamino-2-carboxyethyl>thio-2-azetidinone 
• 100-11-8 1-bromomethyl-4-nitro-benzene 

Downstream Products

• 152560-41-3 (3S,4R)-3-<(R)-1-tert-butyldimethylsilyloxyethyl>-4-<(R)-2-amino-2-(4-nitrobenzyloxycarbonyl)ethyl>thio-2-azetidinone 
• 152560-44-6 (3S,4R)-3-<(R)-1-tert-butyldimethylsilyloxyethyl>-4-<2-diazo-2-(4-nitrobenzyloxycarbonyl)ethyl>sulfonyl-2-azetidinone 
• 152560-42-4 (3S,4R)-3-<(R)-1-tert-butyldimethylsilyloxyethyl>-4-<2-diazo-2-(4-nitrobenzyloxycarbonyl)ethyl>thio-2-azetidinone 
• 152560-36-6 4-nitrobenzyl (3S,5R,6S)-6-<(R)-1-tert-butyldimethylsilyloxyethyl>-3-(2,2-bisnor)penicillante 
• 152560-37-7 4-nitrobenzyl (3S,5R,6S)-6-<(R)-1-hydroxyethyl>-3-(2,2-bisnor)penicillanate 

Relevant academic research and scientific papers

SYNTHESIS OF PENAMS FROM 1H-AZETIDINONES BY INTRAMOLECULAR CARBENOID INSERTION

Construction of the penam ring system has been achieved by dirhodium tetraacetate cyclization of 4-thio-1H-azetidinone derivatives bearing an α-diazoester appendage.The sulfur atom of 4-thioethers interferes by reacting with the electrophilic metal carbene, but the corresponding sulfone and sulfoxides undergo the prescribed cyclization exclusively.Nmr studies on obtained bisnorpenams indicate pseudoequatorial puckering for the thiazolidine ring of the S-sulfoxide, while the parent sulfide and the R-sulfoxide exist as pseudoaxial conformers.