Candida antarctica lipase B-catalyzed ring opening of 4-arylalkyl-substituted β-lactams
摘要:
The Lipolase-catalyzed ring opening of racemic 4-benzyl- 3 and 4-phenylethyl-2-azetidinone 4 was performed with 0.5 equiv of H2O in diisopropyl ether at 45 degrees C. The resulting (S)-beta-amino acid 5 or 6 (ee >= 87%) and (R)-beta-lactam 7 or 8 (ee > 99%,,) enantiomers could easily be separated. The ring opening of enantiomeric beta-lactams with 18% aqueous HCl afforded the corresponding enantiopure beta-amino acid hydrochlorides 9 and 10 (ee > 99%). (c) 2007 Elsevier Ltd. All rights reserved.
Improved enzymatic syntheses of valuable β-arylalkyl-β-amino acid enantiomers
作者:Gábor Tasnádi、Enikő Forró、Ferenc Fülöp
DOI:10.1039/b920731g
日期:——
hydrolyses of β-amino esters with H2O (0.5 equiv.) in t-BuOMe or in i-Pr2O at 45 °C are described. The enantiomers of biologically relevant β-arylalkyl-substituted β-amino acids, and especially (R)-3-amino-3-(2,4,5-trifluorophenyl)butanoic acid, the intermediate of the new antidiabetic drug sitagliptine, were prepared with high enantiomeric excesses (ee≥96%) and in good yields (≥42%).