A Practical One-Step Synthesis of 1,2-Oxazoline Derivatives from Unprotected Sugars and Its Application to Chemoenzymatic<i>β</i>-<i>N</i>-Acetylglucosaminidation of Disialo-oligosaccharide
作者:Masato Noguchi、Tsukasa Fujieda、Wei Chun Huang、Masaki Ishihara、Atsushi Kobayashi、Shin-ichiro Shoda
DOI:10.1002/hlca.201200414
日期:2012.10
facile and practical method for synthesis of sugar oxazolines (=dihydrooxazoles) from the corresponding N‐acetyl‐2‐amino sugars has been developed by using 2‐chloro‐1,3‐dimethyl‐1H‐benzimidazol‐3‐ium chloride (CDMBI) as a dehydrative condensing agent. The intramolecular dehydrative reaction between the 2‐acetamido group and the anomeric OH group of unprotected N‐acetyl‐2‐amino sugars took place smoothly
通过使用2-氯-1,3--3-二甲基-1H-苯并咪唑-3-氯化铵,开发了一种从相应的N-乙酰-2-氨基糖合成糖恶唑啉(=二氢恶唑)的简便实用方法。CDMBI)作为脱水缩合剂。未保护的N-乙酰-2-氨基糖的2-乙酰氨基基团与端基OH基团之间的分子内脱水反应在H 2 O中平稳进行,导致形成1,2-恶唑啉(= 4,5-二氢恶唑)部分,收率很好。由于反应在H 2中进行在不使用任何保护基的情况下,所得的恶唑啉可用作有效的糖基供体,用于随后的酶促糖基化。我们已经成功地证明了由突变型内切N-乙酰氨基葡糖苷酶催化的二低聚寡糖部分到对硝基苯基N-乙酰氨基葡糖苷的高效化学酶转糖基化反应,而没有分离出二聚寡糖恶唑啉作为合成中间体。