A new tandem one-pot acetalation-acetylation procedure is reported which streamlines routine protecting-group manipulation of carbohydrate molecules in production of differentially protected O- and thioglycosides. This new procedure eliminates the use of highly toxic pyridine, and p-toluenesulfonic acid is employed as catalyst for acetalation and acetylation. Synthetic utility of the new procedure is demonstrated in the expeditious preparation of differentially protected glycosides from a wide variety of carbohydrate substrates including unprotected O-glycosides, thioglycosides, and N-acetyl neuraminic acid ester.
报道了一种新的
串联一锅
缩醛化-乙酰化程序,该程序简化了在生产差异保护的 O- 和
硫代糖苷时
碳水化合物分子的常规保护基操作。这种新工艺消除了剧毒
吡啶的使用,并采用
对甲苯磺酸作为
缩醛化和乙酰化的
催化剂。新方法的合成效用在从多种
碳水化合物底物(包括未保护的 O-糖苷、
硫代糖苷和
N-乙酰神经氨酸酯)快速制备差异保护糖苷方面得到了证明。