73308-44-8

Upstream product

• 674-82-8 4-methyleneoxetan-2-one 
• 1750-36-3 (E)-N-benzylidenebenzenamine 
• 121766-35-6 1,4-diphenyl-3-(1-nitroethylidene)azetidin-2-one 
• 22086-33-5 1,4-diphenyl-3-dichloro-azetidine-2-one 
• 108-24-7 acetic anhydride 
• 29834-36-4 trans-3-bromo-1,4-diphenylazetidin-2-one 
• 87419-59-8 (3S*,4R*)-3-(R*)-(1-Hydroxyethyl)-1,4-diphenyl-2-azetidinon 
• 62-53-3 aniline 
• 112383-87-6 1,4-diphenylazetidine-2,3-dione 
• 67638-32-8 3-hydroxy-1,4-diphenyl-azetidin-2-one 
• 58296-60-9 3,3-bis-ethylsulfanyl-1,4-diphenyl-azetidin-2-one 
• 126189-10-4 3-[1-Nitro-eth-(Z)-ylidene]-1,4-diphenyl-azetidin-2-one 
• 106399-67-1 Formic acid (R)-1-((3S,4S)-2-oxo-1,4-diphenyl-azetidin-3-yl)-ethyl ester 
• 106399-66-0 (3S,4S)-3-((S)-1-Hydroxy-ethyl)-1,4-diphenyl-azetidin-2-one 

Downstream Products

• 106399-68-2 (3S,4S)-3-((R)-1-Hydroxy-ethyl)-1,4-diphenyl-azetidin-2-one 
• 106399-66-0 (3S,4S)-3-((S)-1-Hydroxy-ethyl)-1,4-diphenyl-azetidin-2-one 

Relevant academic research and scientific papers

Synthesis of N,4-diaryl substituted β-lactams via Kinugasa cycloaddition/rearrangement reaction

The methodology of construction of N,4-diaryl substituted β-lactam framework, based on the Kinugasa cycloaddition/rearrangement sequence is presented. The series of protected chiral propargyl alcohols was treated with diaryl nitrones to afford mainly the

Mechanistic investigation of the ring opening in the Staudinger cycloaddition involving ketenes with electron-withdrawing substituents

The cycloaddition of ketenes and imines (Staudinger cycloaddition) is a general method for the synthesis of various β-lactams. However, reactions of imines and ketenes with electron-withdrawing substituents produce α,β-unsaturated alkenamides, ring-opening products of the intermediates generated from imines and the ketenes, even as sole products, besides the desired β-lactams. The mechanism of the formation of α,β-unsaturated alkenamides was investigated. The results indicate that the α,β-unsaturated alkenamides are generated via a base-induced C=C bond isomerization followed by electrocyclic ring opening of the formed azacyclobutenes (=1,2-dihydroazetes; cf. Scheme 3). Copyright

Active site mapping of porcine liver esterase (PLE) and porcine pancreatic lipase (PPL): Stereo and regiochemical outcome of hydrolysis of conformationally constrained esters

The regio and stereoselectivity of PLE and PPL-catalyzed hydrolysis of a number of conformationally constrained substrates have been studied. The results are discussed based on the existing active site models for the two enzymes.

Synthetic studies of carbapenem and penem antibiotics. II. Synthesis of 3-acetyl-2-azetidinones by (2 + 2) cycloaddition of diketene and schiff bases

It was found that (2 + 2) cycloaddition reaction of diketene with Schiff bases was effectively promoted by imidazole as a catalyst to afford 3-acetyl-2-azetidinone derivatives 4. As an application of this new method, a practical asymmetric synthesis of 4 and its conversion into (3S,4S)-4-carboxy-1-(di-p-anisylmethyl)-3-[(R)-1-hydroxyethyl]-2-azeti dinone, which is a key intermediate for the synthesis of carbapenem and penem antibiotics, were accomplished.

Tributyltin Hydride Addition to Nitroalkenes: A Convenient Procedure for the Conversion of Nitroalkenes into Nitroalkanes and Carbonyl Compounds

A new procedure for the reduction of nitroalkenes by using n-tributyltin hydride as reducing agent is desribed.The reaction proceeds under almost neutral conditions and works well even in the presence of other reduceable functionalities.Hydrolysis and Nef reaction of the resulting nitronates furnished nitroalkanes and carbonyl compounds respectively in high yields.Application of this methodology to the preparation of β-lactam building blocks is also made.

ELECTROCHEMICAL STUDIES ON Β-LACTAMS. PART 4. ELECTROACETYLATION OF Β-LACTAMS.

Electroreduction of 3-bromo- and 3,3-dichloro-β-lactams 1 carried out at the potential of the first voltammetric peak and in the presence of acetic anhydride gives 3-acetyl-β-lactams 2.The electrosynthesis is highly stereoselective, as only the acetyl der

SYNTHETIC UTILITY OF AZETIDINE-2,3-DIONES: A NEW APPROACH TO 3-HYDROXYETHYL-β-LACTAMS AND α-AMINOACID DERIVATIVES

Baeyer-Villiger oxidation of azetidine-2,3-diones provides a new route to α-aminoacid-N-carboxyanhydrides.Conversion of azetidine-2,3-diones into 3-acetyl-β-lactams is also described.

Asymmetric Synthesis of (1'R,3R,4R)-4-Acetoxy-3(1'-((tert-butyldimethylsilyl)oxy)ethyl)-2-azetidinone and Other 3-(1'-Hydroxyethyl)-2-azetidinones from (S)-(+)-Ethyl 3-Hydroxybutanoate: Formal Total Synthesis of (+)-Thienamycin

The synthesis of (1'R,3R,4R)-4-acetoxy-3-(1'-((tert-butyldimethylsilyl)oxy)ethyl)-2-azetidinone, an important precursor for synthesis of carbapenems and penems, is detailed.The methodology utilized relies on the addition, cyclization reaction between the dianion of (S)-(+)-ethyl 3-hydroxybutanoate and N-arylaldimines.The syntheses of other useful optically active 3-(hydroxyethyl)-2-azetidinones are presented.A study of factors influencing the stereochemistry in the addition, cyclization reaction for the formation of 3-(1'-hydroxyethyl)-2-azetidinones is detailed.

Reductive Ring Contraction of Mesoionic Thiazol-4-ones to Azetidin-2-ones

A series of anhydro-2,3,5-triaryl-4-hydroxythiazolium hydroxides was prepared and desulfurized with Raney nickel.The reduction was stereospecific and gave cis-1,3,4-triphenylazetidin-2-ones.Desulfurization in the presence of triphenylphosphine gave the corresponding trans-azetidinones.Consideration of the possible mechanistic pathways led to the conclusion that the reaction proceeds through formation of biradical-dipole, hydrogenation to a 1,4-dipole, and ring closure.It was also concluded that in the preparation of β-lactams by the nonconcerted cycloaddition of imines and ketenes the first step (dipole formation) is the stereochemistry-determining step.