The thio-Mitsunobu reaction: a useful tool for the preparation of 2,5-anhydro-2-thio- and 3,5-anhydro-3-thiopentofuranosides
作者:Oliver Schulze、Jürgen Voss、Gunadi Adiwidjaja、Falk Olbrich
DOI:10.1016/j.carres.2004.04.020
日期:2004.7
The unprotected methyl L-arabinofuranosides, D-ribofuranosides and D-xylofuranosides are transformed into the corresponding S-acetyl-5-thio derivatives by the thio-Mitsunobu reaction. Mesylation and subsequent reaction with sodium hydrogen carbonate led, depending on the configuration of the intermediate, to 2,5-anhydro-2-thio- or 3,5-anhydro-3-thiopentofuranosides. Due to inversion at C-3 or C-2 during
通过硫代-Mitsunobu反应将未保护的甲基L-阿拉伯呋喃糖苷,D-核呋喃糖苷和D-木呋喃糖苷转化为相应的S-乙酰基-5-硫代衍生物。取决于中间体的构型,甲磺酸化和随后与碳酸氢钠的反应导致2,5-脱水-2-硫代-或3,5-脱水-3-硫代呋喃呋喃糖苷。由于在分子内亲核取代过程中在C-3或C-2处发生倒位,所以产物表现出L-lyxo-,D-阿拉伯糖基或D-lyxo-构型。类似地,甲基2,3-脱水-D-呋喃核糖苷生成具有完整2,3-环氧乙烷基团的5-硫代-S-乙酸盐,将其与碳酸氢钠的环氧化物开环和伴随的闭环反应,仅形成3, 5-脱水-3-硫代-D-木呋喃糖苷。相关的3,通过使3,5-二-O-甲酰基-D-阿拉伯呋喃糖苷与硒化氢钠反应,获得5-脱水-3-硒代-D-呋喃呋喃糖苷。多次X射线衍射分析证明了产品的结构。