Stereocontrolled synthesis of four diastereomeric C-aryl manno- and talofuranosides
作者:Elisa Ravarino、Sunit Kumar Jana、Roland Fröhlich、Ralph Holl
DOI:10.1016/j.carres.2012.08.023
日期:2012.11
the desired C-glycosides was achieved by a Mitsunobu reaction or by preparing the 1-O-benzoyl-4-O-methylsulfonyl derivative 7 which was then treated with sodium methoxide. Final hydrolysis of the 5,6-O-isopropylidene protecting group led to the diastereomeric diols (1S,4R)-4a, (1S,4S)-4b, (1R,4R)-4c, and (1R,4S)-4d, representing versatile building blocks for further synthetic transformations.
在从D-甘露聚糖-1,4-内酯1a开始的手性池合成中,四个非对映体C-芳基呋喃糖苷(1S,4R)-4a,(1S,4S)-4b,(1R,4R)-4c,和(1R,4S)-4d以立体控制的方式获得。合成途径的关键步骤包括非对映异构半缩酮(4R)-2a和(4S)-2b的立体选择性还原,以及所得二醇(1R,4R)-5a,(1S,4R)-的立体特异性环醚化5c和(1S,4S)-5d。通过Mitsunobu反应或通过制备1-O-苯甲酰基-4-O-甲基磺酰基衍生物7来实现导致所需的C-糖苷的这种闭环,然后将其用甲醇钠处理。5,6-O-异亚丙基保护基的最终水解导致生成非对映体二醇(1S,4R)-4a,(1S,4S)-4b,(1R,4R)-4c和(1R,4S)-4d ,