The reaction of glycosyl donor phenyl 2,3,4,6‐tetra‐ O ‐benzyl‐1‐thio‐β‐D‐glucopyranoside with NIS/TfOH(cat.) was systematically studied under various reaction conditions. Neither the molecular sieve pore size nor amount of NIS activator was found to have an effect on the α/β‐ratio in reaction with L‐menthol as glycosyl acceptor. Increasing concentration and the amount of triflic acid catalyst, however was found to increase the β‐selectivity in certain cases. Also, lowering temperature was found to have a strong effect on the glycosylation outcome.

中文翻译：

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各种反应参数如何影响硫糖苷和NIS / TfOH活化的化学糖基化中的端基异构选择性？

在各种反应条件下，系统地研究了糖基供体苯基2,3,4,6-四-O-苄基-1-硫代-β-D-吡喃葡萄糖苷与NIS / TfOH（cat。）的反应。与L-薄荷醇作为糖基受体反应时，分子筛孔径和NIS活化剂的量均未发现对α/β比率有影响。然而，在某些情况下，增加三氟甲磺酸催化剂的浓度和用量会增加β-选择性。另外，发现降低温度对糖基化结果具有强烈影响。