Racemic and Enantiopure Synthesis and Physicochemical Characterization of the Novel Taste Enhancer <i>N</i>-(1-Carboxyethyl)-6-(hydroxymethyl)pyridinium-3-ol Inner Salt
作者:Renaud Villard、Fabien Robert、Imre Blank、Gérald Bernardinelli、Tomislav Soldo、Thomas Hofmann
DOI:10.1021/jf034246+
日期:2003.7.1
racemic mixture and as pure (+)-(S) and (-)-(R) enantiomers, respectively. 5-(Hydroxymethyl)-2-furaldehyde was used as key intermediate and was reacted with l-alanine under alkaline conditions to obtain racemic 1. Alternatively, reductive amination of 5-(hydroxymethyl)-2-furaldehyde with Raney-Ni/hydrogen and l- or d-alanine followed by mild oxidation led to (+)-(S)-1 and (-)-(R)-1, respectively. Racemization
已开发出便利的合成方法,以克数形式获得了外消旋混合物和纯净的(+)-(S)新型味觉增强剂N-(1-羧乙基)-6-(羟甲基)吡啶-3-醇1,称为alapyridaine。 )和(-)-(R)对映异构体。使用5-(羟甲基)-2-呋喃醛作为关键中间体,并在碱性条件下与1-丙氨酸反应,得到外消旋体1。或者,用阮内镍/氢对5-(羟甲基)-2-呋喃醛进行还原胺化反应。 1-或d-丙氨酸随后轻度氧化分别导致(+)-(S)-1和(-)-(R)-1。外消旋作用在碱性和沸腾条件下通过碳负离子促进,亚氨基阳离子的吸电子作用和吡啶鎓部分的共振稳定能力促进了碳负离子的形成。在这种情况下 如X射线衍射所示,在苯酚(1)和苯酚盐(1-H)形式的1:1混合物中获得1。外消旋体1形成具有高分子组织的单斜晶体,其中存在酚型(RS)-1,酚盐型(RS)-1-H,钠阳离子和乙醇分子。[Na(1)(1-H)。(C(2)H(6)O)