Preparation and crystal structure of spiro(5,7-dimethoxy-1(1H)oxo-2-benzopyran-3(4H),1′-cyclohexane)
作者:V. K. Gupta、D. I. Brahmbhatt、U. R. Pandya、S. Goswami
DOI:10.1007/s10870-005-1288-7
日期:2005.4
Spiro(5,7-dimethoxy-1(1H)oxo-2-benzopyran-3(4H),1′-cyclohexane) (C16H20O4) was prepared by alkylation of o-lithio 3,5-dimethoxy-N-methyl benzamide with methylene cyclohexane oxide followed by alkaline hydrolysis and its crystal structure was determined by X-ray crystallographic techniques. The compound crystallizes into monoclinic space group P21/c with unit cell parameters: a = 11.914(3) Å, b = 9.861(3) Å, c = 12.508(7) Å, β = 91.34(3)∘, Z = 4. The structure has been solved by direct methods and refined to R = 0.039 for 1870 observed reflections. The heterocyclic ring adopts distorted sofa conformation while cyclohexane ring assumes a highly symmetric chair conformation. The dihedral angle between the mean planes of isocoumarin nucleus and cyclohexane ring is 105.51(5)∘. Molecules are held together in the crystal by C=H ... O hydrogen bonds.
通过邻二硫 3,5-二甲氧基-N-甲基苯甲酰胺与亚甲基环己烷氧化物的烷基化反应,然后进行碱性水解,制备了螺(5,7-二甲氧基-1(1H)氧代-2-苯并吡喃-3(4H),1′-环己烷)(C16H20O4),并通过 X 射线晶体学技术确定了其晶体结构。该化合物的晶体为单斜空间群 P21/c,单胞参数为:a = 11.914(3) Å, b = 9.861(3) Å, c = 12.508(7) Å, β = 91.34(3)∘, Z = 4。该结构已通过直接方法求解,并在 1870 次观测反射中精制为 R = 0.039。杂环采用扭曲的sofa构象,而环己烷环则采用高度对称的椅子构象。异香豆素核与环己烷环的平均平面之间的二面角为 105.51(5)∘。分子在晶体中通过 C=H ... O 氢键结合在一起。O 氢键结合在一起。