96163-72-3

Upstream product

• 64-17-5 ethanol 
• 344-25-2 D-Prolin 
• 575452-53-8 (+)-ethyl (3R,6S)-6-[(R)-1-phenylbutoxy]-1,2-oxazinane-3-carboxylate 
• 73472-94-3 ethyl 3-bromo-2-(hydroxyimino)propanoate 
• 575452-52-7 (+)-ethyl (6S)-6-[(R)-1-phenylbutoxy]-5,6-dihydro-4H-1,2-oxazine-3-carboxylate 

Downstream Products

• 575452-35-6 (+)-1-(tert-butyl) 2-ethyl (2R)-pyrrolidine-1,2-dicarboxylate 
• 2873-36-1 (3S,8aR)-3-isobutyl-hexahydropyrrolo[1,2-a]pyrazine-1,4-dione 
• 631922-74-2 (3R,8aR)-3-benzylhexahydropyrrolo[1,2-a]pyrazine-1,4-dione 
• 77087-63-9 N-(tert-butyloxycarbonyl)-L-phenylalanyl-D-proline methyl ester 
• 32021-26-4 3-benzylhexahydropyrrolo[1,2-a]pyrazin-1,4-dione 
• 49864-70-2 D-10-<β-N-(1,4-Diazabicyclo<4.3.o>nonanyl)propionyl>-2-chlorophenothiazine 
• 3705-27-9 (R)-(+)-1,4-diazabicyclo<4.3.0>nonane-2,5-dione 
• 96193-27-0 (8aR)-1,2,3,4,6,7,8,8a-octahydropyrrolo[1,2-a]pyrazine 
• 96163-73-4 N-Chloroacetyl-D-proline ethyl ester 

Relevant academic research and scientific papers

Stereospecific Synthesis of 3,4-Dihydro-2 H-naphtho-1,4-oxazin-2-ones by Unification of Benzoxepine-4-carboxylates with Chiral Amino Acid Ethyl Esters

A novel and efficient stereocontrolled method has been developed for the preparation of chiral 3,4-dihydro-2H-naphtho[1,2-b][1,4]oxazin-2-ones by the reaction of benzoxepine-4-carboxylates with chiral amino acid ethyl esters for the first time. The chiral 3,4-dihydro-2H-naphtho-1,4-oxazinones have been achieved in one step by the formation of C-N, C-C, and C-O bonds.

Stereochemistry and conformation of skyllamycin, a non-ribosomally synthesized peptide from streptomyces sp. Acta 2897

Skyllamycin is a non-ribosomally synthesized cyclic depsipeptide from Streptomyces sp. Acta 2897 that inhibits PDGF-signaling. The peptide scaffold contains an N-terminal cinnamoyl moiety, a β-methylation of aspartic acid, three β-hydroxylated amino acids and one rarely occurring α-hydroxy glycine. With the exception of α-hydroxy glycine, the stereochemistry of the amino acids was assigned by comparison to synthetic reference amino acids applying chiral GC-MS and Marfey-HPLC analysis. The stereochemistry of α-hydroxy glycine, which is unstable under basic and acidic conditions, was determined by conformational analysis, employing a combination of data from NOESY-NMR spectroscopy, simulated annealing and free MD simulations. The simulation procedures were applied for both R- and S-configured α-hydroxy glycine of the skyllamycin structure and compared to the NOESY data. Both methods, simulated annealing and free MD simulations independently support S-configured α-hydroxy glycine thus enabling the assignment of all stereocenters in the structure of skyllamycin and devising the role of two-component flavin dependent monooxygenase (Sky39) as S-selective.

A new strategy for the stereoselective synthesis of unnatural α-amino acids

A new method for the synthesis of racemic non-proteinogenic α-amino acids has been developed, which involves (i) hetero-Diels-Alder addition of ethyl 2-nitrosoacrylate to electron rich alkenes such as enol ethers, enamines and allylsilanes, (ii) NaCNBH3 reduction of the CN bond in the oxazines thus generated, the stereochemistry of the products being controlled by epimerisation of the thermodynamically less stable isomer to the more stable one, (iii) protection of the N-H group as N-Boc and (iv) finally, N-O bond cleavage of both free and protected products to give proline or bis-homoserine derivatives, respectively. An example with concomitant reduction of the carboxylate group, resulting in the formation of the respective amino alcohol is reported. Applying this methodology to a homochiral enol ether, the protected parent d-proline was prepared in enantiomerically pure form, whereas the asymmetric synthesis of the respective bis-homoserine was unsuccessful. Graphical Abstract.