Total synthesis of lycopene-5,6-diol and γ-carotene-5′,6′-diol stereoisomers and their HPLC separation
作者:Yumiko Yamano、Yuya Nishiyama、Atsushi Aoki、Takashi Maoka、Akimori Wada
DOI:10.1016/j.tet.2017.02.048
日期:2017.4
Lycopene-5,6-diol stereoisomers (1a,b) and (2a,b) and γ-carotene-5′,6′-diol stereoisomers (3a,b) and (4a,b) were synthesized by a stepwise C15 + C10 + C15 double Wittig reaction strategy. The key compounds erythro(anti)-C15-dihydroxy aldehydes 17a,b and their threo(syn)-stereoisomers 23a,b were prepared via Sharpless asymmetric epoxidation of geraniol and nerol followed by acidic hydrolysis of the
通过逐步C 15合成番茄红素5,6-二醇立体异构体(1a,b)和(2a,b)和γ-胡萝卜素5',6'-二醇立体异构体(3a,b)和(4a,b) + C 10 + C 15双重维蒂希反应策略。关键化合物赤型(抗)-C 15-二羟基醛17a,b及其苏式(顺式)-立体异构体23a,b是通过香叶醇和神经醇的Sharpless不对称环氧化,然后以立体有择的方式对环氧化物进行酸性水解而制备的。对映体富集反-异构体,通过2,3- epoxygeranyl 3,5- dinitrobenzoates重结晶的方式获得图9A,B,而顺式-异构体是经由dihydroxyneryl 3,5- dinitrobenzoates的重结晶如对映体纯的形式获得的21A,B。为了确定天然产物的绝对立体化学,使用带有手性固定相的色谱柱建立了每种对映体1a,b - 4a,b的HPLC分离方法。