A novel synthesis of 1-O-acetyl-2,3,5-tri-O-benzoyl-D-ribofuranose (I) has been described starting from 1,2:3,5-di-O-cyclohexylidene-α-D-xylofuranose (II), obtained directly from the crude xylose syrup originated from corncobs. Partial acid hydrolysis of II gave 1,2-O-cyclohexylidene-α-D-xylofuranose (III). Selective benzoylation of primary C-5 hydroxyl group of III followed by tosylation of C-3 hydroxyl group afforded IV in an overall yield of 67%. Mild acid methanolysis of IV gave the corresponding methyl xylofuranosides V which were further benzoylated to afford 2,5-di-O-benzoyl derivatives VI in 65% yield. Solvolysis of VI in 95% DMF gave a mixture of 2,5- and 3,5-di-O-benzoylribofuranosides VII, which were subsequently converted into the corresponding tribenzoates VIII. An acetolysis of VIII afforded I in an overall yield of 96% related to VI.
描述了一种新颖的合成方法,从玉米芯产生的原始木糖浆中直接获得1,2:3,5-双<斜体>O斜体>-环己基甲基-α-D-木糖呋喃糖(II),并从II部分酸水解得到1,2-<斜体>O斜体>-环己基甲基-α-D-木糖呋喃糖(III)。选择性苯甲酰化III的主要C-5羟基,然后对C-3羟基进行甲磺酰化,得到IV,总收率为67%。对IV进行温和的酸性甲醇解,得到相应的甲基木糖呋喃糖(V),进一步苯甲酰化,得到2,5-双<斜体>O斜体>-苯甲酰衍生物VI,收率为65%。在95% DMF中VI的溶剂解除反应,得到2,5-和3,5-双<斜体>O斜体>-苯甲酰核糖呋喃糖混合物VII,随后转化为相应的三苯甲酸酯VIII。对VIII进行乙酰解,得到I,总收率相对于VI为96%。