Synthesis of Phytyl- and Chroman-Derivatized Photoaffinity Labels Based on α-Tocopherol
作者:Huangshu Lei、Jeffrey Atkinson
DOI:10.1021/jo000029l
日期:2000.4.1
prepared by substituting photosensitive functional groups at either the terminus of an alkyl chain of varying length mimicking the phytyl tail or on C-3 of the chroman portion of tocopherol. The alkyl chain-modified compounds 2a-d contain a hexyl to nonyl alkyl chain extending from C-2 of the chroman, terminating in a tetrafluoroazidobenzyloxy group. These compounds were prepared starting from the commercially
α-生育酚的光亲和性类似物已经通过在模仿生育酚尾部的植酸尾部的变长的烷基链的末端或在生育酚的苯并二氢吡喃的C-3上取代光敏官能团而制备。烷基链改性的化合物2a-d包含从苯并二氢吡喃的C-2延伸的己基至壬基烷基链,其终止于四氟叠氮基苄氧基。这些化合物从市售的Trolox酸4开始制备,然后进行酯化,保护和还原为甲硅烷基保护的Trolox醛7,使用Wittig化学方法将其偶联到不同的ω-羟基bro溴化物上。烯烃产物的还原,与对叠氮基四氟苄基溴的偶合以及酚硅烷基的脱保护,以优异的收率得到化合物2a-d。色度官能化的光亲和标记是从受保护的生育酚苯烯16b合成的,后者是制备3-羟基衍生物的关键中间体,方法是还原由Jacobsen催化剂直接产生的环氧化物,或通过在湿DME中用NBS处理得到两种立体异构体将其溴环化并还原得到苯酚保护的C-3醇19a,b。然后将这些醇转化为重氮乙酸酯,并除去保护基,得到3-