Asymmetric Alkylations of a Sultam-Derived Glycine Equivalent: Practical preparation of enantiomerically pure ?-amino acids
作者:Wolfgang Oppolzer、Robert Moretti、Changyou Zhou
DOI:10.1002/hlca.19940770823
日期:1994.12.14
products 3. Acidic hydrolysis of the pure products 3 gives (aminoacyl)sultams 4 which by mild saponification furnish pure α-amino acids 5 in good overall yields from 2, along with recovered auxiliary 1 (Scheme 1). Pure ω-protected α,ω-diamino acids and α-amino-ω-(hydroxyamino)acids 12–16 are readily accessible from (ω-haloacyl)sultams 3via reaction with N-nucleophiles followed by acidic and basic hydrolyses
在无水介质中,手性甘氨酸衍生物2与“活化的”有机卤化物在超声辅助的相转移催化下或活化和非活化的有机卤化物在无水介质中的烷基化提供了(大部分是结晶的)烷基化产物3。纯产物3的酸性水解得到(氨基酰基)sultams 4,其通过温和皂化以2的良好总产率提供纯的α-氨基酸5以及回收的助剂1(方案1)。纯的ω-保护的α,ω-二氨基酸和α-氨基-ω-(羟基氨基)酸12-16可容易地从(ω-卤代酰基)sultams 3通过与N-亲核试剂反应,然后进行酸性和碱性水解(方案2)。提出了通过对其N-(3,5-二硝基苯甲酰基)脯氨酰基衍生物17的HPLC分析来可靠测定α-氨基酸的对映体纯度的方法。