Optical resolution of N-carbobenzoxy-α-methoxyglycine

Structure−Activity Relationship Studies of Gonadotropin-Releasing Hormone Antagonists ContainingS-Aryl/Alkyl Norcysteines and Their Oxidized Derivatives

“…Control oxidation experiments were performed on acyline (8) Table 1 for actual ratios in the column entitled "purity"). L-and D-Ncy(2-naphthyl) introduced at position 1 in analogues 9 and 10 did not react with NaIO 4 , and no oxidation product was identified on RP-HPLC.…”

“…One of our analogues, acyline [Ac-D-2Nal 1 ,D-4Cpa 2 ,D-3Pal 3 ,4Aph(Ac) 5 ,D-4Aph(Ac) 6 ,Ilys 8 ,DAla 10 ]GnRH, 24 (8 , Table 1) is a potent and long acting GnRH antagonist distributed by the National Institutes of Health (NIH) to academic researchers. 29,30 However, acyline readily forms gels in aqueous buffers at concentrations ≥10 mg/mL and cannot be formulated for very long duration of action.…”

Optical resolution and absolute configuration of N‐Benzyloxycarbonyl‐α‐alkoxyglycines

“…Consequently, (+)-and (−)-Cbz-Gly(OR)-OH (R = Me, Et, and Pr i ) were deduced to possess D-and Lconfigurations, respectively, which was in agreement with the configurational assignment of Cbz-Gly(OMe)-OH based on the 1 H NMR comparison and biological activity of the Gly(OMe)-containing peptides. 4 Although porcine pancreatic lipase and papain were known to L-selectively hydrolyze N-protected ␣-amino acid esters possessing various alkyl and aralkyl side chains, 5,6 the present study has shown that the enantioselectivity is retained in the case of amino acid derivatives with alkoxy side chains.…”

“…Optical resolution of (±)-Cbz-Gly(OMe)-OH and determination of the absolute configuration of each enantiomer were already reported. 4 Here we will describe optical resolution and absolute configuration of Cbz-Gly(OPr i )-OH and Cbz-Gly(OEt)-OH which correspond to the N-protected ␤-oxa analogs of leucine and norvaline, respectively. Fractional recrystallization of diastereomeric salts or diastereomeric esters accomplished the resolutions and the absolute configurations were based on enzymatic enantioselective hydrolysis, 5,6 which was also supported by chiroptical study 7,8 and HPLC analysis.…”

Preparation of l-phenylalaninol with high ee selectivity by catalytic hydrogenation of l-phenylalaninate over Cu/ZnO/Al2O3 catalyst

“…The formation of chiral amino alcohols, especially L-phenylalaninol, has become the subject of considerable interest because of their importance in asymmetric synthesis, peptide and pharmaceutical chemistry, resolution of racemic mixtures, synthesis of insecticidal compounds, etc. [1][2][3][4][5][6][7][8][9][10] L-Phenylalaninol has often been prepared by reducing the corresponding L-phenylalanine or esters. In most cases, metal hydrides were used as reducing agents, which are reactive at low temperature thereby guaranteeing the integrity of the stereogenic center.…”