蔗糖-6-乙酯的制备及提纯

Preparation and purification of 6-O-acetyl sucrose

以蔗糖和原乙酸三乙酯为原料,对甲苯磺酸为催化剂,酯化合成蔗糖-4,6-环酯,水解生成蔗糖-4-乙酯和蔗糖-6-乙酯,在叔丁胺作用下蔗糖-4-乙酯发生酰基迁移,转化为蔗糖-6-乙酯。考察了物料比、反应温度、催化剂和水的用量对反应的影响。研究表明适宜的条件为:6.84 g蔗糖需要10 mL原乙酸三乙酯、50 mg对甲苯磺酸,0℃反应180 min,加3 mL水裂解反应90 min,再加1 mL叔丁胺,酰基迁移反应90 min。产品经二氯甲烷析晶纯化,纯度达到96.5%。用ESI、1HNMR进行了表征。

6-O-acetyl sucrose was prepared from sucrose and triethyl orthoacetate used as starting materials,through the synthesis of sucrose alkyl-4,6-orthoacylate in the presence of p-toluenesulfonic acid used as catalyst,followed by hydrolyzation of 4-O-acetyl sucrose or 6-O-acetyl sucrose.Under the action of tert-butylamine 4-O-acetyl sucrose was transformed to 6-O-acetyl sucrose through the acyl transfer reaction.Reaction conditions such as material ratio,reaction temperature,catalyst and water dosage have been studied.It has been shown that optimum conditions were as follows.In the presence of 50 mg of p-toluenesulfonic acid used as then catalyst,6.84 g of sucrose reacted upon 10 mL of triethyl orthoacetate for 180 min at 0 ℃,and then 3 mL of water was added to the reaction mixture,which was then subjected to hydrolyzation for 90 min,followed by acyl transfer reaction for 90 min after addition of 1 mL of tert-butylamine.The purity of product reached 96.5% after crystallization in dichloromethane.The structure of 6-O-acetyl sucrose was characterized by ESI and 1HNMR.