Crystal structures are reported for three fluoro- or chloro-substituted 1′-deoxy-1′-phenyl-β-D-ribofuranoses, namely 1′-deoxy-1′-(2,4,5-trifluorophenyl)-β-D-ribofuranose, C11H11F3O4, (I), 1′-deoxy-1′-(2,4,6-trifluorophenyl)-β-D-ribofuranose, C11H11F3O4, (II), and 1′-(4-chlorophenyl)-1′-deoxy-β-D-ribofuranose, C11H13ClO4, (III). The five-membered furanose ring of the three compounds has a conformation between a C2′-endo,C3′-exotwist and a C2′-endoenvelope. The ribofuranose groups of (I) and (III) are connected by intermolecular O—H...O hydrogen bonds to six symmetry-related molecules to form double layers, while the ribofuranose group of (II) is connected by O—H...O hydrogen bonds to four symmetry-related molecules to form single layers. The O...O contact distance of the O—H...O hydrogen bonds ranges from 2.7172 (15) to 2.8895 (19) Å. Neighbouring double layers of (I) are connected by a very weak intermolecular C—F...π contact. The layers of (II) are connected by one C—H...O and two C—H...F contacts, while the double layers of (III) are connected by a C—H...Cl contact. The conformations of the molecules are compared with those of seven related molecules. The orientation of the benzene ring is coplanar with the H—C1′ bond or bisecting the H—C1′—C2′ angle, or intermediate between these positions. The orientation of the benzene ring is independent of the substitution pattern of the ring and depends mainly on crystal-packing effects.
报告了三种
氟或
氯取代的 1′-脱氧-1′-苯基-β-D-
呋喃核糖的晶体结构,即 1′-脱氧-1′-(2,4,5-三
氟苯基)-β-D-
呋喃核糖、
C11H11F3O4,(I);1′-脱氧-1′-(2,4,6-三
氟苯基)-β-D-
呋喃核糖, ,(II);以及 1′-(4-
氯苯基)-1′-脱氧-β-D-
呋喃核糖,
C11H13ClO4,(III)。这三种化合物的五元
呋喃糖环的构象介于 C2′-内旋、C3′-外旋和 C2′-内包络之间。(I)和(III)的核
呋喃糖基团通过分子间 O-H...O 氢键与六个对称相关分子连接形成双层,而(II)的核
呋喃糖基团通过 O-H...O 氢键与四个对称相关分子连接形成单层。O-H...O 氢键的 O...O 接触距离从 2.7172 (15) Å 到 2.8895 (19) Å 不等。(I)的相邻双层通过非常微弱的分子间 C-F...π 接触连接。(II)的双层通过一个 C-H...O和两个 C-H...F接触连接,而(III)的双层则通过一个 C-H...Cl接触连接。这些分子的构象与七个相关分子的构象进行了比较。苯环的取向与 H-C1′ 键共面,或与 H-C1′-C2′ 角成二叉,或介于这两个位置之间。苯环的取向与苯环的取代模式无关,主要取决于晶体的堆积效应。