Nitrate esters in the generation of amino acid radicals
Nitrate esters, prepared by treatment of β-hydroxy-α-amino acid derivatives with nitric acid, react with tributyltin hydride to give the corresponding alkoxyl radicals. These radicals readily undergo β-scission, providing a convenient route for the regiocontrolled production of α-carbon-centred amino acid radicals. By examining the partitioning of the alkoxyl radicals between the β-scission process and the competing hydrogen transfer reaction, it has been possible to evaluate the influence of electronic and steric effects on the β-scission reaction and the formation of the carbon-centred radicals.
Easton, Christopher J.,Ivory, Andrew J.,Smith, Craig A.
p. 503 - 507
(2007/10/03)
Resolution of β-hydroxy-α-amino acids by the action of proteases on their N-acyl methyl esters
Methyl N-acetyl phenylserinates (1, 2), methyl N-acetyl nitrophenylserinates (3, 4), and methyl N-benzoyl threoninates (5, 6) were resolved conveniently into the enantiomers with high optical purities by enzymatic hydrolysis in the presence of α-chymotryp