Kindel P K, Cheng L A
Department of Biochemistry, Michigan State University, East Lansing 48824.
Carbohydr Res. 1990 May 15;199(1):55-65. doi: 10.1016/0008-6215(90)84092-9.
The complete acetylation of apiitol required 9 h when acetic anhydride at 120 degrees was used and sodium acetate was the catalyst. Both apiitol pentaacetate and apiitol tetraacetate were detected before acetylation was complete. When the reaction was done in dimethyl sulfoxide, with 1-methylimidazole as the catalyst, a third compound was observed, and identified as 1,2,4-tri-O-acetyl-3-C-(acetoxymethyl)-3-O-(methylthiomethyl)-D-glycero- tetrito l [3-O-(methylthiomethyl)apiitol tetraacetate] by gas-liquid chromatography and mass spectrometry. In N,N-dimethylformamide, with 1-methylimidazole as catalyst, the acetylation of apiitol was essentially complete in 4 h at 85 degrees, and the formation of methylthiomethyl ether was avoided. A method for preparing alditol acetates using 1-methylimidazole as the catalyst, and suitable for samples containing apiose as well as ordinary sugars, is described. The separation of apiitol pentaacetate from xylitol pentaacetate by gas-liquid chromatography proved difficult. However, a virtually complete separation of the peracetates of apiitol and xylitol as well as complete separation of those of rhamnitol, fucitol, arabinitol, mannitol, galactitol, glucitol, and myo-inositol, plus apiitol tetraacetate and 3-O-(methylthiomethyl)apiitol tetraacetate, was accomplished with a 30 m x 0.53 mm (i.d.) SP-2380 column in 49 min, and on a 30 m x 0.75 mm (i.d.) SP-2330 column in 82 min. A complete separation of apiitol and xylitol pentaacetates as well as four other alditol peracetates was obtained with a 60 m DB-1 column in 15.2 min, however this column did not resolve the acetates of fucitol and arabinitol. A variety of other columns and column conditions were ineffective.
当使用120℃的乙酸酐并以乙酸钠为催化剂时，木糖醇完全乙酰化需要9小时。在乙酰化完成之前就检测到了木糖醇五乙酸酯和木糖醇四乙酸酯。当反应在二甲基亚砜中以1-甲基咪唑为催化剂进行时，观察到了第三种化合物，通过气液色谱和质谱鉴定为1,2,4-三-O-乙酰基-3-C-(乙酰氧基甲基)-3-O-(甲硫基甲基)-D-甘油四醇[3-O-(甲硫基甲基)木糖醇四乙酸酯]。在N,N-二甲基甲酰胺中，以1-甲基咪唑为催化剂，木糖醇在85℃下4小时基本完成乙酰化，并且避免了甲硫基甲基醚的形成。描述了一种以1-甲基咪唑为催化剂制备糖醇乙酸酯的方法，该方法适用于含有阿洛糖以及普通糖类的样品。通过气液色谱法将木糖醇五乙酸酯与木糖醇五乙酸酯分离很困难。然而，使用30 m×0.53 mm（内径）的SP-2380柱在49分钟内，以及在30 m×0.75 mm（内径）的SP-2330柱上在82分钟内，基本上完全分离了木糖醇和木糖醇的全乙酸酯，以及鼠李糖醇、岩藻糖醇、阿拉伯糖醇、甘露醇、半乳糖醇、葡萄糖醇和肌醇的全乙酸酯，还有木糖醇四乙酸酯和3-O-(甲硫基甲基)木糖醇四乙酸酯。使用60 m的DB-1柱在15.2分钟内实现了木糖醇和木糖醇五乙酸酯以及其他四种糖醇全乙酸酯的完全分离，然而该柱无法分离岩藻糖醇和阿拉伯糖醇的乙酸酯。各种其他柱和柱条件均无效。
