Synthesis of d-erythro-2-pentulose and d-threo-2-pentulose and analysis of the 13C- and 1H-n.m.r. spectra of the 1-13C- and 2-13C-substituted sugars
作者:Tapani Vuorinen、Anthony S. Serianni
DOI:10.1016/0008-6215(91)80142-a
日期:1991.1
immobilized D-xylose (D-glucose) isomerase (E.C.5.3.1.5). The equilibrium compositions of 1 and 2 (furanose anomers and acyclic keto forms) in 2H2O were determined from 13C-n.m.r. spectra (75 MHz) of the 2-13C-labeled derivatives. The conformational properties of the cyclic and acyclic forms in 2H2O were assessed with the use of 1H-1H, 13C-1H, and 13C-13C spin-coupling constants obtained from 1H-n.m.r
通过氢化相应的同位素正构和13C取代的D-来制备D-赤藓-2-戊糖(1)和D-苏-2-戊糖(2)以及它们的1-13C和2-13C取代的衍生物五氧化二-2-戊糖与钯碳催化剂。所述苏式异构体及其标记的衍生物可替代地由具有固定的D-木糖(D-葡萄糖)异构酶(EC5.3.1.5)的同位素正态和13C-取代的D-木糖制备。由2-13C标记的衍生物的13C-nmr光谱(75 MHz)确定2H2O中1和2(呋喃糖异构体和无环酮形式)的平衡组成。使用从1H-nmr(620 MHz)和13C-nmr(75 MHz)获得的1H-1H,13C-1H和13C-13C自旋耦合常数来评估2H2O中环状和非环状形式的构象性质光谱。与结构上相关的醛呋喃呋喃糖酶相比,2-戊呋喃糖酶更优选其中异头羟基基团准轴向取向的构象。非环状酮形式1和2的强双极化羰基似乎稳定了O-1和O-3被羰基氧取代的链构象。