Abstract: Highly pure (2R,3S)-3-tert-butoxycarbonylamino-1-chloro-2-hydroxy-4-phenylbutane or (2S,3R)-3-tert-butoxycarbonylamino-1-chloro-2-hydroxy-4-phenylbutane may be conveniently produced in high yield by: (a) reacting compound (1) with lithiumchloromethane to give compound (2) and at least a byproduct; (b) dissolving compound (2) and the byproduct in a polar solvent and adding water to the solution to precipitate compound (2) as crystals; (c) reducing the crystals of compound (2) to give compound (3) and at least its diastereomer as an impurity; (d) adding sulfuric acid thereto to give compound (4) and at least its diastereomer as an impurity; and (e) precipitating compound (4) as crystals from a solution containing acetic acid ester or acetic acid ester.

Abstract: Herein are disclosed a process for increasing in purity, or purifying, an N-protected-?-aminoalcohol which process comprises (i) adding water to a polar organic solvent in which an N-protected-?-aminoalcohol such as a (2R,3S)- or (2S,3R)-3-tert-butoxycarbonylamino-1-halo-2-hydroxy-4-phenylbutane or the like, or (ii) crystallizing such an N-protected-?-aminoalcohol from a diol or a diol-based mixed solvent, and a process for producing the corresponding N-protected-?-aminoepoxide which process comprises treating, with a base, the thus purity-enhanced N-protected-?-aminoalcohol. Such N-protected-?-aminoalcohols and N-protected-?-aminoepoxides are both useful as synthetic intermediates for medicine compounds, such as, e.g., HIV protease inhibitor and the like.

Abstract: N-carbamate protected-3-amino-1,2-epoxy-4-(hydroxy substituted phenyl)butane may be produced in high optical purity and in high yield, by hydrogenating N-carbamate protected-3-amino-1-chloro-2-hydroxy-4-(benzyloxy substituted phenyl)butane in the presence of a metal catalyst to give N-carbamate protected-3-amino-1-chloro-2-hydroxy-4-(hydroxy substituted phenyl)butane and treating this compound with a base.

Abstract: Herein are disclosed a process for increasing in purity, or purifying, an N-protected-&bgr;-aminoalcohol which process comprises (i) adding water to a polar organic solvent in which an N-protected-&bgr;-aminoalcohol such as a (2R,3S)-or (2S,3R)-3-tert-butoxycarbonylamino-1-halo-2-hydroxy-4-phenylbutane or the like, or (ii) crystallizing such an N-protected-&bgr;-aminoalcohol from a diol or a diol-based mixed solvent, and a process for producing the corresponding N-protected-&bgr;-aminoepoxide which process comprises treating, with a base, the thus purity-enhanced N-protected-&bgr;-aminoalcohol. Such N-protected-&bgr;-aminoalcohols and N-protected-&bgr;-aminoepoxides are both useful as synthetic intermediates for medicine compounds, such as, e.g., HIV protease inhibitor and the like.

Abstract: The present invention provides a production method of an optically active &bgr;-amino-&agr;-hydroxycarboxylic acid, which includes the following steps (a)-(c): (a) treating an optically active N-carbamate protected &bgr;-amino epoxide with an acid to give an optically active 5-hydroxymethyl-2-oxazolidinone; (b) oxidizing the resulting compound in the presence of 2,2,6,6-tetramethyl-1-piperidinyloxy and hypochlorite to give an optically active 4-benzyl-2-oxo-5-oxazolidinecarboxylic acid; and (c) treating the 4-benzyl-2-oxo-5-oxazolidinecarboxylic acid with a base, and a production method of an optically active N-carbamate protected &bgr;-amino-&agr;-hydroxycarboxylic acid which includes protection of the amino group with a carbamate type protecting group. The industrial production method of the present invention can produce these compounds efficiently.

Abstract: The invention relates to a method for industrially producing highly pure (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoepoxide (crystal) or (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoalcohol.

Abstract: Herein is disclosed a process for producing an &agr;-aminohalomethyl ketone derivative which comprises subjecting to catalytic reduction the corresponding &agr;-aminodihalomethyl ketone derivative, and which process is efficient and suited for industrial production thereof.

Abstract: The present invention provides a production method of an optically active &bgr;-amino-&agr;-hydroxycarboxylic acid, which includes the following steps (a)-(c):

Abstract: The invention relates to a method for industrially producing highly pure (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoepoxide (crystal) or (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoalcohol.

Abstract: Herein is disclosed a process for producing an &agr;-aminohalomethyl ketone derivative which comprises subjecting to catalytic reduction the corresponding &agr;-aminodihalomethyl ketone derivative, and which process is efficient and suited for industrial production thereof.