Hua D H, Roche D, Bharathi S N, Wu X, Robinson P D
Department of Chemistry, Kansas State University, Manhattan 66506.
Acta Crystallogr C. 1992 Oct 15;48 ( Pt 10):1866-8. doi: 10.1107/s0108270192002051.
C18H19O3P, M(r) = 314.32, monoclinic, P2(1)/n, a = 5.726 (6), b = 14.234 (7), c = 20.08 (1) A, beta = 92.54 (7) degrees, V = 1635 (4) A3, Z = 4, Dx = 1.277 g cm-3, lambda(Mo K alpha) = 0.71069 A, mu = 1.71 cm-1, F(000) = 664, T = 296 K, R = 0.042, 1813 unique observed reflections. The X-ray structure determination of the title compound shows that the dioxaphosphorinane ring has a chair conformation in which the phosphoryl O atom (P=O) is equatorial, which explains the absence of substantial NMR deshielding by its P=O group on H(4) and H(6), which are axial.
C₁₈H₁₉O₃P，相对分子质量M(r)=314.32，单斜晶系，P2(1)/n，a = 5.726(6)，b = 14.234(7)，c = 20.08(1) Å，β = 92.54(7)°，V = 1635(4) ų，Z = 4，Dx = 1.277 g cm⁻³，λ(Mo Kα)= 0.71069 Å，μ = 1.71 cm⁻¹，F(000)= 664，T = 296 K，R = 0.042，1813个独立观测反射。标题化合物的X射线结构测定表明，二氧磷杂环己烷环具有椅式构象，其中磷酰基O原子（P=O）处于平伏键，这解释了其P=O基团对轴向的H(4)和H(6)没有显著的NMR去屏蔽作用。
