Reaction of (1b) and (1d) with the acetal (2a) in presence of trimethylsilyl trifluoromethanesulfonate at −70° C gives the α-glucosides (3a) and (4a), whereas (1a) and (1c) lead to the β-glucosides (4c) and (4b). At 0° C reaction of (1a) with the acetals (2b-g) gives exclusively the α-glucosides (3b-g).
(1b)和(1d)与
缩醛(2a)在三
甲基甲
硅烷基
三氟甲磺酸酯存在下于-70°C反应生成α-
葡萄糖苷(3a)和(4a),而(1a)和(1c)导致β -
葡糖苷(4c)和(4b)。在0℃下,(1a)与
乙缩醛(2b-g)的反应仅产生α-
葡糖苷(3b-g)。