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制备了2＇,3＇-O-二苯甲酰基尿嘧啶核糖核苷U(BZ)_2,并在DMF溶液中培养得到单晶。单晶经X射线衍射测定,属三斜晶系,空间群为Pl。晶胞参数a=5.734(1)(?),b=10.124(3)(?),c=11.905(3)(?),α=73.07(2)°,β=84.36(2)°,γ=81.61(2)°,Z=1。用CAD-4四圆衍射仪收集衍射数据。用直接法解晶体结构,用块对角矩阵最小二乘法修正,对3154个独立反射,最终R=0.070。U(BZ)_2的碱基相对于糖环为β构型,两个苯甲酰基在空间上远离5＇-OH,使5＇-OH周围空隙较大,因而苯甲酰基作为Ur的2＇,3＇-羟基的保护基,对5＇-OH的反应不存在立体障碍。
The 2 ’, 3’-O-dibenzoyl uracil riboside U (BZ) 2 was prepared and cultured in DMF solution to obtain single crystals. Single crystal by X-ray diffraction determination, is a triclinic, space group Pl. The cell parameters a = 5.734 (1) (?), B = 10.124 (3) (?) And c = 11.905 (3),? = 73.07 (2) °,? = 84.36 = 81.61 (2) °, Z = 1. Diffraction data was collected using a CAD-4 four-circle diffractometer. The crystal structure was solved by the direct method and corrected by the least square method of block diagonal matrix. For 3154 independent reflections, the final R = 0.070. The base of U (BZ) _2 is in β configuration relative to the sugar ring. Two benzoyl groups are spatially separated from the 5’-OH, resulting in larger voids around the 5’-OH. Therefore, the benzoyl group acts as the 2 ’ , 3’-hydroxyl group, there is no steric hindrance to the reaction of 5’-OH.