A novel synthesis, including asymmetric synthesis, of α-quaternary α-amino acid methyl esters from ketones via sulfinyloxiranes
作者:Tsuyoshi Satoh、Mizue Hirano、Akio Kuroiwa
DOI:10.1016/j.tetlet.2005.02.111
日期:2005.4
methanol to give α-azido methyl esters in good overall yields. Catalytic hydrogenation of the α-azido esters afforded α-quaternary α-amino acid methyl esters in quantitative yields. Starting from β-tetralone and optically pure (R)-chloromethyl p-tolyl sulfoxide, an asymmetricsynthesis of optically pure (R)-(+)-methyl 2-aminotetraline-2-carboxylate was realized in good overall yields.
A synthesis of optically active α-quaternary α-amino acids and esters by assembling three components, ketones, (R)-chloromethyl p-tolyl sulfoxide, and sodium azide, via sulfinyloxiranes
yields. The oxidation of the azido aldehydes with iodine in methanol in the presence of KOH followed by the catalytic hydrogenation resulted in α-quaternary α-amino acid methyl esters in good yields. When these reactions were carried out starting from unsymmetrical ketones and optically pure (R)-chloromethyl p-tolyl sulfoxide, a new method for a synthesis of optically active α-quaternary α-amino acids