68223-06-3

Upstream product

• 186581-53-3 diazomethane 
• 26607-51-2 N-benzyloxycarbonyl-D-alanine 
• 102988-93-2 C₁₆H₂₁NO₆ 

Downstream Products

• 852248-32-9 (3-bromo-1-(R)-methyl-2-oxopropyl)carbamic acid benzyl ester 
• 142035-70-9 methyl (R)-3-(benzyloxycarbonylamino)-butanoate 
• 1256379-76-6 2-methyl-3-aminobutyric acid 
• 1443463-61-3 C₁₄H₁₉NO₄ 
• 1256379-69-7 C₃₇H₅₁N₃O₈ 
• 1402730-13-5 (R)-benzyl 1-(5-amino-1H-pyrazol-3-yl)ethylcarbamate 
• 852248-33-0 2-phenyl-4-(1-(R)-benzyloxycarbonylaminoethyl)-1H-imidazole 
• 406220-14-2 benzyl (R)-2-methyl-3-oxoazetidine-1-carboxylate 

Relevant academic research and scientific papers

Complexation of chiral di (N-Protected α-Amino)-β-diketones with some transition metals

Chiral Di (N-protected a-amino)-b-diketones and its transition metal complexes have been synthesized. Di(N-protected a-amino)-b- diketones were prepared by reaction of activation of N-protected- a-amino acids (imidazolide) with a-diazoketones derived from natural amino acids in presence of lithium diisopropyl amid in tetrahydrofuran as a solvent at -78 °C and treatment the product with rhodium acetate to remove diazo group. The synthesized compounds were characterized by analytical techniques viz: IR, NMR and elemental analysis. The thermal stability of the newly synthesized metal complexes have been studied.

Total synthesis and biological evaluation of grassypeptolide A

Herein, we describe in full our investigations into the synthesis of grassypeptolide A (1) in 17 linear steps with an overall yield of 11.3 %. In particular, this work features the late-stage introduction of sensitive bis(thiazoline) heterocycles and 31-membered macrocyclization conducted at the sterically congested secondary amide site in superb conversion (72 % yield). Biological evaluation indicated that grassypeptolide A significantly inhibited cancer cell proliferation in a dose-dependent manner. It induced cancer cell apoptosis, which was associated with increased cleavage of poly(ADP-ribose) polymerase (PARP) and decreased expression of bcl-2 and bcl-xL. Furthermore, grassypeptolide A also caused cell cycle redistribution by increasing cells in the G1 phase and decreasing cells in the S and G2 phases. In addition, cell cycle arrest was correlated with downregulation of cyclin D and upregulation of p27 and p21. Cytotoxic activity: Synthesis of grassypeptolide A, an anticancer marine cyclodepsipeptide, in 17 linear steps with an overall yield of 11.3 % is described (see figure). Subsequent biological evaluation indicated that grassypeptolide A significantly inhibited cancer-cell proliferation in a dose-dependent manner. Copyright

Synthesis of N-urethane protected α-aminoalkyl-α-cyanomethyl ketones; Application to the synthesis of 3-substituted 5-amino-1H-pyrazole tethered peptidomimetics

The preparation of N-protected amino/peptide α-cyanomethyl ketones through cyanation of the corresponding α-bromomethyl ketones is described. The utility of the resulting α-cyanomethyl ketones in the synthesis of 3-substituted-5-amino-1H-pyrazoles has also been demonstrated. In both steps a wide range of N-protected amino/peptide acids has been employed and the products are obtained in good yield. The enantiomeric purity of both the α-cyanomethyl ketones and pyrazoles were confirmed by chiral HPLC analysis of the corresponding Z-protected d- and l-Ala-OH as model substrates. The synthesis of peptide pyrazolecarboxamides is also delineated. Georg Thieme Verlag Stuttgart · New York.

Synthesis and characterization of chiral di(N-protected-α-amino) diazo-β-diketones from α-diazoketones and imidazolides derived from amino acids

Di(N-protected-α-amino)diazo-β-diketones were prepared by the reaction of activated N-protected-α-amino acids (imidazolides) with α-diazoketones, derived from natural amino acids, in the presence of lithium diisopropylamide in tetrahydrofuran as the solvent at -78 °C.

Chiral imidazole derivatives synthesis from enantiopure N-protected α-amino acids

A route to the preparation of enantiopure ligands based on a 2-phenylimidazol ring is described. The stereogenic centre is placed into the chain bonded to the fourth carbon of the imidazole ring. The synthesis starts from inexpensive and readily available

Total synthesis of polyoximic acid

The structure and stereochemistry of polyoximic acid, a degradation product of polyoxins, was originally designated as trans-3-ethylidene-L-azetidine-2-carboxylic acid. However, total synthesis revealed that the correct structure was in fact cis-3-ethylidene-L-azetidine-2-carboxylic acid, which was confirmed by X-ray crystallography. The synthesis of the trans-isomer was also done and its identity was confirmed by X-ray analysis as well. The key step for constructing the four-membered ring was a rhodium catalyzed carbenoid insertion into the N - H bond of a β-amino acid derivative. The stereoselectivity of the exo-double bond was controlled by conducting a Horner-Emmons-Wadsworth or a Wittig reaction to generate the trans- and cis-isomers, respectively. Weinreb's amide was used as a latent methyl group for the separation of trans and cis mixtures. The double bond stereochemistry of polyoximic acid in the parent polyoxin was also confirmed to be cis by extensive 2D NMR studies.