An Efficient Synthesis of Optically Pure (<i>R</i>)- and (<i>S</i>)-2-(aminomethyl)alanine ((<i>R</i>)- and (<i>S</i>)-ama) and (<i>R</i>)- and (<i>S</i>)-2-(aminomethyl)leucine ((<i>R</i>)- and (<i>S</i>)-aml)
作者:Daniel Obrecht、Helena Karajiannis、Christian Lehmann、Peter Schönholzer、Clive Spiegler、Klaus Müller
DOI:10.1002/hlca.19950780317
日期:1995.5.10
An efficient synthesis of enantiomerically pure (R)- and (S)-2-(aminomethyl)alanine ((R)- and (S)-Ama) 1a and (R)- and (S)-2-(aminomethyl)leucine ((R)- and (S)-Aml) 1b is described (Schemes 1 and 2). Resolution of the racemic amino acids was achieved using L-phenylalanine cyclohexylamide (2) as chiral auxiliary. The free amino acids 1a, b were converted to the Nα-Boc,Nγ-Z-protected derivatives 11a
对映体纯的(R)-和(S)-2-(氨基甲基)丙氨酸((R)-和(S)-Ama)1a和(R)-和(S)-2-(氨基甲基)亮氨酸的有效合成((R)-和(S)-Aml)1b被描述(方案1和2)。使用L-苯丙氨酸环己酰胺(2)作为手性助剂,可拆分外消旋氨基酸。游离氨基酸1a中,B被转换到Ñ α -Boc,Ñ γ -Z-保护的衍生物图11a,b(方案3)准备好掺入肽中。基于非对映异构体肽8a,8b和9b的三个晶体结构,确定两个系列中的绝对构型。对于结构8b和9b观察到β-TurnI型几何形状,而8a以扩展的骨架构象结晶。