摘要 |
Methods for production of chirally pure alpha -amino acids and N-sulfonyl alpha -amino acids are described. An aldehyde and a cyanide salt are reacted with an alpha -methylbenzylamine to afford a product. The product reacts with a strong acid, is neutralized, and is extracted. The resulting product is subsequently hydrogenated and hydrolyzed to provide a product which is dissolved in a strong acid to provide a salt of a chirally pure alpha -amino acid, which is reacted to provide the chirally pure alpha -amino acid. Another method involves mixing ephedrine hemihydrate and an N-sulfonyl alpha -ethylnorvaline in ethanol at a molar ratio of 1:1; heating the mixture to dissolve the solids; cooling to allow formation of a precipitate; washing with an organic solvent to give diastereomeric salt; recrystallizing the salt; dissolving the recrystallized salt in an organic solvent and strong aqueous acid, separating the layers; washing the organic extract; drying and concentrating to provide chirally pure N-sulfonyl alpha -amino acid. |