Efficient asymmetric synthesis of unnatural β-amino acids

C Bolm, I Schiffers, CL Dinter, L Defrère, A Gerlach…

Index: Bolm; Schiffers; Dinter; Defrere; Gerlach; Raabe Synthesis, 2001 ,  # 11  p. 1719 - 1730

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Citation Number: 48

Abstract

Abstract The simple and highly enantioselective methanolysis of cyclic meso-anhydrides mediated by cinchona alkaloids leads to a broad variety of dicarboxylic acid mono-methyl esters with up to 99% ee. From these products, unnatural N-protected β-amino esters can be obtained by means of Curtius degradation of the corresponding acyl azides. Subsequent cleavage of the protecting groups leads to the free β-amino acids in excellent yields. By ...