138039-48-2

Upstream product

• 97911-48-3 (+/-)-6-azabicyclo[3.2.0]hept-3-en-7-one 
• 63838-48-2 6-Azabicyclo<3.2.0>hept-3-en-7-one 
• 542-92-7 cyclopenta-1,3-diene 

Downstream Products

• 959745-77-8 ethyl (1RS,2RS,3RS,5SR)-2-(((9H-fluoren-9-yl)methoxy)carbonylamino)-6-oxabicyclo[3.1.0]hexane-3-carboxylate 
• 959745-77-8 (1R*,2R*,3S*,5S*)-ethyl 2-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-6-oxabicyclo[3.1.0]hexane-3-carboxylate 
• 959745-89-2 ethyl (1RS,2RS,3RS,4RS)-4-azido-2-(tert-butoxycarbonylamino)-3-hydroxycyclopentane-1-carboxylate 
• 959745-75-6 ethyl (1R*,2R*,3S*,5S*)-2-(tert-butoxycarbonylamino)-6-oxabicyclo[3.1.0]hexane-3-carboxylate 
• 959745-89-2 ethyl (1SR,2RS,3RS,4RS)-4-azido-2-(tert-butoxycarbonylamino)-3-hydroxycyclopentane-1-carboxylate 
• 959745-75-6 ethyl (1RS,2RS,3RS,5SR)-2-(tert-butoxycarbonylamino)-6-oxabicyclo[3.1.0]hexane-3-carboxylate 
• 771440-02-9 2-amino-cyclopent-3-enecarboxylic acid ethyl ester 
• 1607805-88-8 ethyl (2S,3S)-3-benzamido-6-oxo-2-(4-oxopentyl)heptanoate 
• 1607805-87-7 triethyl (3S,4S)-3-benzamidoheptane-1,4,7-tricarboxylate 
• 1607805-86-6 ethyl (2S,3S,E)-3-benzamido-6-oxo-2-[(E)-4-oxopent-2-enyl]hept-4-enoate 
• 1607805-84-4 triethyl (3S,4S,6E)-3-benzamidohepta-(1E)-1,6-diene-1,4,7-tricarboxylate 
• 1607805-83-3 ethyl (2S,3S)-3-benzamido-5-phenyl-2-(3-phenylpropyl)pentanoate 
• 1607805-82-2 ethyl (2S,3S)-3-benzamido-2-propylpentanoate 
• 1607805-80-0 ethyl (2S,3S)-2-allyl-3-benzamidopent-4-enoate 

Relevant academic research and scientific papers

Stereo- and regiocontrolled synthesis of highly functionalized cyclopentanes with multiple chiral centers

The synthesis of some highly substituted three-dimensional cyclopentanes with multiple chiral centers and with high regiochemical and stereochemical diversity has been accomplished starting from cyclopentadiene-derived aminocyclopentenecarboxylic acids. The small-molecular design consisted of stereo- and regiocontrolled functionalization of the starting cyclopentene β- and γ-amino acids through oxirane formation/oxirane opening and afforded regio- and diastereoisomers of orthogonally protected aminocyclopentanecarboxylates.

High-Performance Liquid Chromatographic Enantioseparation of Cyclic β-Amino Acids on Zwitterionic Chiral Stationary Phases Based on Cinchona Alkaloids

Stereoselective high-performance liquid chromatographic separations of eight sterically constrained cyclic β-amino acid enantiomer pairs were carried out using the newly developed Cinchona alkaloid-based zwitterionic chiral stationary phases Chiralpak ZWIX(+) and ZWIX(-). The effects of the mobile phase composition, the nature and concentrations of the acid and base additives, the counterions and temperature on the separations were investigated. The changes in standard enthalpy, Δ(ΔH°), entropy, Δ(ΔS°), and free energy, Δ(ΔG°), were calculated from the linear van't Hoff plots derived from the ln α vs. 1/T curves in the studied temperature range (10-50°C). The values of the thermodynamic parameters depended on the nature of the selectors and the structures of the analytes. Unusual temperature behavior was observed on the ZWIX(-) column: decreased retention times were accompanied by increased separation factors with increasing temperature. On the ZWIX(+) column only enthalpically, whereas on the ZWIX(-) column both enthalpically and entropically driven separations were observed. The elution sequence was determined in all cases and was observed to be the opposite on ZWIX(+) and on ZWIX(-). Chirality 27:563-570, 2015.

A selective synthesis of fluorinated cispentacin derivatives

A facile selective method has been developed for the synthesis of new fluorine-containing cispentacin stereoisomers. Mono- and difluorinated cispentacin derivatives were synthetized from a bicyclic β-lactam in five or six steps involving a regio- and stereoselective hydroxylation through iodooxazoline formation, followed by deoxygenation by fluorination. Starting from an enantiomerically pure bicyclic β-lactam obtained by enzymatic resolution of the racemic compound, an enantiodivergent procedure allowed the preparation of both dextro- and levorotatory difluorinated cispentacins. Mono- and difluorinated cispentacin derivatives were synthetized from a bicyclic β-lactam in five or six steps. An enantiodivergent procedure allowed the preparation of both dextro- and levorotatory difluorinated cispentacins. Copyright

A de Novo stereocontrolled approach to syn- and anti-disubstituted acyclic β2,3-amino acid enantiomers

The stereocontrolled syntheses of functionalized acyclic β2,3-amino acid derivatives in enantiomerically pure form were performed by starting from enantiopure cis- and trans-2-aminocyclopent-3- enecarboxylates, which were derived from a racemic bicyclic β-lactam. The synthetic strategy involves the stereoselective dihydroxylaton of the C-C double bond of the cyclopentene β-amino esters. The subsequent NaIO 4-mediated ring cleavage affords dialdehyde intermediates that undergo functionalization by a Wittig reaction. The stereocontrolled syntheses of functionalized acyclic β2,3-amino acid derivatives in enantiomerically pure form have been performed in five steps by starting from enantiopure cis- and trans-2-aminocyclopent-3-enecarboxylates, which were derived from a racemic bicyclic β-lactam. Copyright

A de Novo Stereocontrolled Approach to syn- and anti-Disubstituted Acyclic β2,3-Amino Acid Enantiomers

The stereocontrolled syntheses of functionalized acyclic β2,3-amino acid derivatives in enantiomerically pure form were performed by starting from enantiopure cis- and trans-2-aminocyclopent-3-enecarboxylates, which were derived from a racemic bicyclic β-lactam. The synthetic strategy involves the stereoselective dihydroxylaton of the C-C double bond of the cyclopentene β-amino esters. The subsequent NaIO4-mediated ring cleavage affords dialdehyde intermediates that undergo functionalization by a Wittig reaction.

Synthesis of novel isoxazoline-fused cyclic β-amino esters by regio- and stereo-selective 1,3-dipolar cycloaddition

Isoxazoline-fused 2-aminocyclopentanecarboxylate derivatives were regio- and stereo-selectively synthesized by nitrile oxide 1,3-dipolar cycloaddition to cis- or trans-ethyl-2-aminocyclopent-3-enecarboxylates. The compounds were prepared in enantiomerical

Enantiomeric discrimination of cyclic β-amino acids using (18-crown-6)-2,3,11,12-tetracarboxylic acid as a chiral NMR solvating agent

(18-Crown-6)-2,3,11,12-tetracarboxylic acid is an excellent chiral NMR solvating agent for cyclic β-amino acids with cyclopentane, cyclohexane, cycloheptane, cyclopentene, cyclohexene, bicyclo[2.2.1]heptane, and bicyclo[2.2.1]heptene rings. The crown ether was added to the neutral β-amino acids in methanol-d4. A neutralization reaction between the crown ether and β-amino acid forms the ammonium ion needed for favorable association. Enantiomeric discrimination of the two hydrogen atoms α to the amine and carboxylic acid moieties of the β-amino acid was observed with every substrate studied. Trends in the order of the enantiomeric discrimination of certain hydrogen atoms for substrates of similar structures correlate with the absolute configuration.

Novel functionalized cispentacin derivatives. Synthesis of 1,2,3-triazole-substituted 2-aminocyclopentanecarboxylate stereoisomers

Four 1,2,3-triazole-substituted ethyl 2-amino-3-hydroxycyclopentanecarboxylate diastereomers (3,4-disubstituted cispentacins) with a cyclopentane skeleton were prepared in enantiomerically pure form from racemic β-lactam 7 via enzymatic ring opening, epoxidation and selective ring opening of the oxirane ring with sodium azide. The formation of the 1,2,3-triazole ring system involved click chemistry: 1,3-dipolar cycloaddition of the corresponding 4-substituted azidocarboxylates with diethyl acetylenedicarboxylate.

Vapour-assisted enzymatic hydrolysis of β-lactams in a solvent-free system

A new, solvent-free, vapour-assisted method, developed for the synthesis of carbocyclic cis β-amino acid enantiomers through the Candida antarctica lipase B-catalysed enantioselective (E >200) hydrolysis of β-lactams with 0.5 equiv of H2O at 70 °C, has been demonstrated to be applicable on a preparative scale to produce (±)-2 (the starting racemate for cispentacin), (±)-3 (the starting racemate for 4-tert-butylcispentacin, a new cispentacin analogue) and (±)-7 (the starting racemate for 1,4-ethylene-bridged cispentacin).

Diastereo- and enantioselective synthesis of orthogonally protected 2,4-diaminocyclopentanecarboxylates: A flip from β-amino- to β,γ-diaminocarboxylates

(Chemical Equation Presented) Conformationally restricted, orthogonally protected 2,4-diaminocarboxylates with a cyclopentane skeleton were efficiently synthesized from β-lactam 6, the syntheses involving strategies of diastereoselective epoxidation of th