137062-74-9

Upstream product

• 133696-58-9 (E)-2-((1R,5R)-3-Benzyl-7-oxo-4-thia-2,6-diaza-bicyclo[3.2.0]hept-2-en-6-yl)-3-hydroxy-but-2-enoic acid benzhydryl ester 
• 176590-43-5 (Z)-2-((1R,5R)-3-Benzyl-7-oxo-4-thia-2,6-diaza-bicyclo[3.2.0]hept-2-en-6-yl)-3-methanesulfonyloxy-but-2-enoic acid benzhydryl ester 

Downstream Products

• 176513-36-3 (2S,4S,5R,6R)-3-Methylene-4,7-dioxo-6-phenylacetylamino-4λ⁴-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylic acid benzhydryl ester 
• 176513-32-9 (2S,3R,5R,6R)-3-Methyl-7-oxo-6-phenylacetylamino-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylic acid benzhydryl ester 

Relevant academic research and scientific papers

Ring expansion of norpenicillin to 3-norcephalosporin

The Morin ring expansion of penicillin 1-oxides to cephalosporins has been extended to norpenicillin 1-oxides. To this end, both the norpenicillin sulfoxide moiety and the methyl group should be β-oriented. Norpenicillin 1-oxides are prepared from properly protected exomethylene penam derivatives using hydrogen on palladium/carbon and oxidation with 3-chloroperoxybenzoic acid or peroxyacetic acid.