A process is provided for preparing chirally pure S-enantiomers of &agr;-amino acids comprising the steps of: a) preparing an organometallic reagent from an alkyl halide of the formula (R)
2
CH(CH
2
)
n
CH
2
X; b) adding the organometallic reagent to carbon dioxide to afford a carboxylic acid; c) activating the carboxylic acid with an acid chloride, phosphorus trichloride, acid anhydride, or thionyl chloride in the presence of a tertiary amine base; d) reacting the product of step c) with an alkali metal salt of S-4-benzyl-2-oxazolidinone; e) treating the product of step d) with a strong non-nucleophilic base to form an enolate anion; f) trapping the enolate anion with 2,4,6-triisopropylbenzenesulfonyl azide to afford an oxazolidinone azide; g) hydrolyzing the oxazolidinone azide with an aqueous base to afford an &agr;-azido acid; h) reducing the &agr;-azido acid to the &agr;-amino acid; and i) recrystallizing the &agr;-amino acid to the chirally pure &agr;-amino acid. A process is also provided for preparing chirally pure S-enantiomers of &bgr;-amino alcohols further comprising the steps of reducing the crude &agr;-amino acid to the &bgr;-amino alcohol and recrystallizing the &bgr;-amino alcohol to the chirally pure &bgr;-amino alcohol. A process is further provided for preparing chirally pure S enantiomers of N-sulfonyl &bgr;-amino alcohols further comprising the steps of sulfonylating the &bgr;-amino alcohol with 5-chloro-thiophene-2-sulfonyl halide; and recrystallizing to afford the chirally pure N-sulfonyl &bgr;-amino alcohols.
提供了一种制备手性纯S-对映体
α-氨基酸的过程,包括以下步骤:a) 从具有
化学式(R)2CH(
CH2)n X的烷基卤化物制备有机
金属试剂;b) 将有机
金属试剂加入
二氧化碳以得到
羧酸;c) 在三级胺碱存在下,用酸
氯化物、
三氯化磷、酸酐或
氯化硫酰
氯激活
羧酸;d) 将步骤c)的产物与S-4-苄基-
2-噁唑烷酮的碱
金属盐反应;e) 用强非亲核碱处理步骤d)的产物以形成烯醇负离子;f) 用2,4,6-
三异丙基苯磺酰
氮化物捕获烯醇负离子以得到
噁唑烷酮
氮化物;g) 用
水性碱
水解
噁唑烷酮
氮化物以得到α-
叠氮酸;h) 还原α-
叠氮酸以得到
α-氨基酸;i) 对
α-氨基酸进行再结晶以得到手性纯
α-氨基酸。还提供了一种制备手性纯S-对映体β-
氨基醇的过程,进一步包括将粗
α-氨基酸还原为β-
氨基醇,并对β-
氨基醇进行再结晶以得到手性纯β-
氨基醇。还提供了一种制备手性纯S-对映体N-磺酰基β-
氨基醇的过程,进一步包括用5-
氯硫代苯
磺酰卤化物对β-
氨基醇进行磺酰化;并进行再结晶以得到手性纯N-磺酰基β-
氨基醇。