Abstract: According to the present invention, it becomes possible to perform a process for converting into an ?-substituted cysteine represented by general formula (1) or a salt thereof at low cost and on an industrial scale by employing a process that is routed through a compound represented by general formula (3) to a compound represented by general formula (6). Particularly, by employing a process that is routed through a compound represented by general formula (7-2), it becomes possible to detach a tert-butyl protection group in a simple manner and to produce the compound represented by general formula (1) with high purity. Furthermore, by employing a process that is routed through tert-butylthiomethanol or a process that is routed through a compound represented by general formula (9), it becomes possible to produce a compound represented by general formula (2) without generating bischloromethylether that is an oncogenic substance.

Abstract: According to the present invention, it becomes possible to perform a process for converting into an ?-substituted cysteine represented by general formula (1) or a salt thereof at low cost and on an industrial scale by employing a process that is routed through a compound represented by general formula (3) to a compound represented by general formula (6). Particularly, by employing a process that is routed through a compound represented by general formula (7-2), it becomes possible to detach a tert-butyl protection group in a simple manner and to produce the compound represented by general formula (1) with high purity. Furthermore, by employing a process that is routed through tert-butylthiomethanol or a process that is routed through a compound represented by general formula (9), it becomes possible to produce a compound represented by general formula (2) without generating bischloromethylether that is an oncogenic substance.

Abstract: According to the present invention, it becomes possible to perform a process for converting into an ?-substituted cysteine represented by general formula (1) or a salt thereof at low cost and on an industrial scale by employing a process that is routed through a compound represented by general formula (3) to a compound represented by general formula (6). Particularly, by employing a process that is routed through a compound represented by general formula (7-2), it becomes possible to detach a tert-butyl protection group in a simple manner and to produce the compound represented by general formula (1) with high purity. Furthermore, by employing a process that is routed through tert-butylthiomethanol or a process that is routed through a compound represented by general formula (9), it becomes possible to produce a compound represented by general formula (2) without generating bischloromethylether that is an oncogenic substance.

Abstract: It is an object of the present invention to provide a novel method for producing (1R,2S)/(1S,2R)-1-amino-1-alkoxycarbonyl-2-vinylcyclopropane which is useful as a synthetic intermediate of therapeutic agents for hepatitis C and a synthetic intermediate thereof. According to the present invention, when a trans-2-butene derivative having a leaving group at each of the 1- and 4-positions is reacted with a malonic ester in the presence of a base, a specific amount of an alkali metal alkoxide or an alkali metal hydride is used as the base, and further a specific amount of a malonic ester is used to produce a cyclopropane diester, and further, chiral or achiral 1-amino-1-alkoxy-carbonyl-2-vinylcyclopropane and a salt thereof are synthesized using the cyclopropane diester.

Abstract: It is an object of the present invention to provide a novel method for producing (1R,2S)/(1S,2R)-1-amino-1-alkoxycarbonyl-2-vinylcyclopropane which is useful as a synthetic intermediate of therapeutic agents for hepatitis C and a synthetic intermediate thereof. According to the present invention, when a trans-2-butene derivative having a leaving group at each of the 1- and 4-positions is reacted with a malonic ester in the presence of a base, a specific amount of an alkali metal alkoxide or an alkali metal hydride is used as the base, and further a specific amount of a malonic ester is used to produce a cyclopropane diester, and further, chiral or achiral 1-amino-1-alkoxy-carbonyl-2-vinylcyclopropane and a salt thereof are synthesized using the cyclopropane diester.