摘要:
Provided is an industrially useful process for producing an optically active 2-hydroxy-4-arylbutyric acid or its ester. An optically active acyloxysuccinic anhydride is reacted with an aromatic compound in the presence of a Lewis acid to produce an optically active 2-acyloxy-4-oxo-4-arylbutyric acid. The 2-acyloxy-4-oxo-4-arylbutyric acid is converted to an optically active 2-acyloxy-4-arylbutyric acid through catalytic reduction. The 2-acyloxy-4-arylbutyric acid is hydrolyzed in the presence of an acid or an alkali to produce an optically active 2-hydroxy-4-arylbutyric acid. The 2-hydroxy-4-arylbutyric acid is reacted with an alcohol in the presence of an acid to produce an optically active 2-hydroxy-4-arylbutyric acid ester.
摘要:
Provided is an industrially useful process for producing an optically active 2-hydroxy-4-arylbutyric acid or its ester. An optically active acyloxysuccinic anhydride is reacted with an aromatic compound in the presence of a Lewis acid to produce an optically active 2-acyloxy-4-oxo-4-arylbutyric acid. The 2-acyloxy-4-oxo-4-arylbutyric acid is converted to an optically active 2-acyloxy-4-arylbutyric acid through catalytic reduction. The 2-acyloxy-4-arylbutyric acid is hydrolyzed in the presence of an acid or an alkali to produce an optically active 2-hydroxy-4-arylbutyric acid. The 2-hydroxy-4-arylbutyric acid is reacted with an alcohol in the presence of an acid to produce an optically active 2-hydroxy-4-arylbutyric acid ester.
摘要:
Provided is an industrially useful process for producing an optically active 2-hydroxy-4-arylbutyric acid or its ester. An optically active acyloxysuccinic anhydride is reacted with an aromatic compound in the presence of a Lewis acid to produce an optically active 2-acyloxy-4-oxo-4-arylbutyric acid. The 2-acyloxy-4-oxo-4-arylbutyric acid is converted to an optically active 2-acyloxy-4-arylbutyric acid through catalytic reduction. The 2-acyloxy-4-arylbutyric acid is hydrolyzed in the presence of an acid or an alkali to produce an optically active 2-hydroxy-4-arylbutyric acid. The 2-hydroxy-4-arylbutyric acid is reacted with an alcohol in the presence of an acid to produce an optically active 2-hydroxy-4-arylbutyric acid ester.
摘要:
A process for producing &agr;-amino-dihalogenated methyl ketone derivatives by reacting an N-protected &agr;-amino acid ester with a dihalomethyl lithium is provided. This process is suitable for the production on an industrial scale and by this process, &agr;-amino-dihalogenated methyl ketone derivatives and &bgr;-amino-&agr;-hydroxycarboxylic acid derivatives can be obtained efficiently and economically advantageously.
摘要:
A process for producing &agr;-aminohalomethyl ketones or N-protected &agr;-aminohalomethyl ketones from specified 3-oxazolidin-5-one derivatives via 5-halomethyl-5-hydroxy-3-oxazolidine derivatives. By this process, &agr;-aminohalomethyl ketones and compounds relating to them can be obtained efficiently and economically in industrial scale.
摘要:
A process for producing &agr;-aminohalomethyl ketones or N-protected &agr;-aminohalomethyl ketones from specified 3-oxazolidin-5-one derivatives via 5-halomethyl-5-hydroxy-3-oxazolidine derivatives. By this process, &agr;-aminohalomethyl ketones and compounds relating to them can be obtained efficiently and economically in industrial scale.
摘要:
An amino group of an &agr;-amino acid ester is protected as an imine, and it is then reacted with a halomethyllithium to obtain an N-protected-&agr;-aminohalomethylketone. Further, this N-protected-&agr;-aminohalomethylketone is treated with an acid to obtain an &agr;-aminohalomethylketone. This process is suited for industrial production, and can produce an &agr;-aminohalomethylketone and its related compounds economically and efficiently.
摘要:
An amino group of an &agr;-amino acid ester is protected as an imine, and it is then reacted with a halomethyllithium to obtain an N-protected-&agr;-aminohalomethylketone. Further, this N-protected-&agr;-aminohalomethylketone is treated with an acid to obtain an &agr;-aminohalomethylketone. This process is suited for industrial production, and can produce an &agr;-aminohalomethylketone and its related compounds economically and efficiently.
摘要:
A process for producing α-aminohalomethyl ketones or N-protected α-aminohalomethyl ketones from specified 3-oxazolidin-5-one derivatives via 5-halomethyl-5-hydroxy-3-oxazolidine derivatives. By this process, α-aminohalomethyl ketones and compounds relating to them can be obtained efficiently and economically in industrial scale.
摘要:
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. The method for producing N-carbamate-protected &bgr;-aminoepoxide crystal, includes one or more of the following steps (a) to (d): (a) dissolving (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoalcohol containing at least the diastereomer as an impurity in a solvent including at least one or more selected from aromatic hydrocarbon solvent, saturated hydrocarbon solvent, aqueous mixture solvent, acetone and 2-propanol, to remove insoluble matters; (b) treating the (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoalcohol with a base, thereby converting the N-carbamate-protected &bgr;-aminoalcohol to (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoepoxide; (c) treating the (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoepoxide containing at least the diastereomer as an impurity with an acid, thereby converting the diastereomer as an impurity to (4S, 5R) or (4R, 5S) oxazolidin-2-one derivative, and optionally separating and removing the resulting oxazolidin-2-one derivative in water or an aqueous mixture solvent; and (d) crystallizing the (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoepoxide in a mixture solvent of water and water-miscible organic solvent. By the methods of the present invention, highly pure (2R, 3S)- or (2S, 3R)-N-carbamate-protected &bgr;-aminoepoxide or (2R, 3S) or (2S, 3R)-N-carbamate-protected &bgr;-aminoalcohol can be efficiently produced.