139501-51-2

Upstream product

• 139472-60-9 2-((2R,3R)-2-Benzenesulfonylsulfanyl-4-oxo-3-phenylacetylamino-azetidin-1-yl)-buta-2,3-dienoic acid 4-methoxy-benzyl ester 
• 183194-06-1 p-methoxybenzyl (Z)-3-chloro-4-{[(p-methylphenyl)sulfonyl]oxy}-2-{2-oxo-3-(phenylacetamido)-4-[(phenylsulfonyl)thio]azetidin-1-yl}-2-butenoate 
• 168418-30-2 p-methoxybenzyl (E)-3-chloro-2-<2-oxo-3-(phenylacetamido)-4-<(phenylsulfonyl)thio>azetidin-1-yl>-4-<<(trifluoromethyl)sulfonyl>oxy>-2-butenoate 
• 168418-31-3 p-methoxybenzyl (E)-3,4-dichloro-2-<2-oxo-3-(phenylacetamido)-4-<(phenylsulfonyl)thio>azetidin-1-yl>-2-butenoate 
• 131857-34-6 (E)-2-((2R,3R)-2-Benzenesulfonylsulfanyl-4-oxo-3-phenylacetylamino-azetidin-1-yl)-4-chloro-3-hydroxy-but-2-enoic acid 4-methoxy-benzyl ester 

Downstream Products

• 139371-98-5 3-methylene-7-oxo-6-phenylacetylamino-4-thia-1-aza-bicyclo[3.2.0]heptane-2-carboxylic acid 4-methoxybenzyl ester 

Relevant academic research and scientific papers

Synthesis of 3-chloro-Δ3-cephem-4-carboxylate by addition/cyclization of allenecarboxylate. Copper(II)-promoted aerobic oxidation of arenesulfinic acids

The selective transformation of allenecarboxylate derived from penicillin into 3-chloro-Δ3-cephem-4-carboxylate was successfully achieved by an addition/cyclization reaction with chloride salts in aerobic media containing a copper(II) catalyst, in which copper(II)-catalyzed aerobic oxidation of in situ generated benzenesulfinate ion into less nucleophilic sulfonate ion prior to the nucleophilic addition of the former ion to the allenecarboxylate would completely eliminate the formation of undesired 3-phenylsulfonyl-Δ3-cephem-4-carboxylate. Under similar aerobic conditions, arenesulfinates salts and arenesulfinic acids were smoothly oxidized to the corresponding sulfonate salts and sulfonic acids, respectively.

Synthesis of 2-exo-methylenepenam and 3-chloro-Δ3-cephem through a sequential reductive 1,2-elimination/S-S bond fission or chloride ion-addition/cyclization of 3,4-disubstituted 2-butenoates in metal salt/metal combinations

Synthesis of 2-exo-methylenepenam 1 through a sequential reductive 1,2-elimination/S-S bond fission/cyclization of 6 was performed by treatment with a PbBr2/Al (or a BiCl3/Al) combination in DMF, while that of 3-chloro-Δ3-cephem 2 through reductive 1,2-elimination/chloride ion-addition/cyclization was attained by use of an AlCl3/Al combination in N-methylpyrrolidone (NMP). The selective transformation of 6 to the allenecarboxylate 3 was also achieved by treatment with an AlBr3/Al combination in NMP. Cyclic voltammograms of 3,4-disubstituted 2-[2-oxo-3-(phenylacetamido)-4-[(phenylsulfonyl)thio]azetidin-1-yl]-2- butenoates (6) exhibit two irreversible reduction peaks responsible for reductive 1,2-elimination of the 3,4-disubstituted 2-butenoate moiety (at less negative potential) and for reductive S-S bond fission of the (phenylsulfonyl)thio moiety, suggesting that the reductive 1,2-elimination of 6 leading to allenecarboxylate 3 would occur prior to the reductive S-S bond cleavage.