Lynch V M, Zinke P W, Martin S F, Davis B E
Department of Chemistry and Biochemistry, University of Texas, Austin 78712.
Acta Crystallogr C. 1991 Apr 15;47 ( Pt 4):910-2. doi: 10.1107/s0108270190011039.
Methyl 3-deoxy-7,8-O-(1-methylethylidene)- 1-O-(phenylmethyl)-alpha-D-manno-2-octalopyranoside cyclic carbonate, (1), C20H26O8, Mr = 394.42, orthorhombic, P2(1)2(1)2(1), a = 10.667 (3), b = 10.7972 (14), c = 16.509 (5) A, V = 1901.4 (8) A3, Z = 4, Dx = 1.38 g cm-3, mu = 0.9960 cm-1, lambda(Mo K alpha) = 0.7107 A, F(000) = 840, T = 298 K, R = 0.0355 for 2248 reflections, Fo greater than or equal to 4[sigma (Fo)]. The X-ray structure was undertaken to confirm the stereochemistry of the substituents on the six-membered pyranose ring. The two rings are cis-fused with ring junction torsion angles of -18.7 (3) degrees for C2-C3-C8-C9 and -18.2 (2) degrees for O4-C3-C8-O7. The six-membered ring assumes a slightly distorted twist conformation while the fused five-membered ring is in the half-chair conformation. The isopropylidene moiety is in the envelope conformation.
3-脱氧-7,8-O-(1-甲基亚乙基)-1-O-(苯基甲基)-α-D-甘露糖-2-辛吡喃糖苷环状碳酸甲酯，(1)，C20H26O8，Mr = 394.42，正交晶系，P2(1)2(1)2(1)，a = 10.667(3)，b = 10.7972(14)，c = 16.509(5)Å，V = 1901.4(8)Å3，Z = 4，Dx = 1.38 g cm-3，μ = 0.9960 cm-1，λ(Mo Kα) = 0.7107 Å，F(000) = 840，T = 298 K，对于2248个反射，R = 0.0355，Fo≥4[σ(Fo)]。进行X射线结构分析以确认六元吡喃糖环上取代基的立体化学。两个环顺式稠合，C2-C3-C8-C9的环连接扭转角为-18.7(3)°，O4-C3-C8-O7的环连接扭转角为-18.2(2)°。六元环呈轻微扭曲的扭转构象，而稠合的五元环呈半椅式构象。亚异丙基部分呈信封式构象。
