5-甲基糠醇-β-D-葡萄糖苷的合成及热裂解

Synthesis and Pyrolysis of 5-methyl furfuryl alcohol-β-D-glucopyranoside

摘要:

摘要：为了开发新型的糖苷类香料，首先以D-葡萄糖为原料，合成了溴代四乙酰葡萄糖(III)，III与5-甲基糠醇(II)进行糖苷化反应，分别采用改进的Koenigs-Knorr法和相转移催化法，合成5-甲基糠醇-2, 3, 4, 6-四-O-乙酰基-β-D-葡萄糖苷(IV)； 最后将化合物IV水解得到目标产物5-甲基糠醇-β-D-葡萄糖苷(V)。中间体和产物结构经1H NMR，13C NMR，IR，HRMS 确证，并对糖苷(V)的热裂解进行了研究。结果表明: ①两种糖苷化方法所得到的产物均为糖苷(IV)，改进的Koenigs-Knorr法优于相转移催化法；②Koenigs-Knorr法的最佳反应条件为：n（5-甲基糠醇）∶n（溴代四乙酰葡萄糖）=1: 1.6，n (5-甲基糠醇)：n (Ag2CO3 )=1: 1.5，回流反应4 h，化合物IV的产率为 42.9%。③目标糖苷(V)热裂解后能够释放出5-甲基糠醛、5-甲基糠醇等多种香味成分，因此在食品、烟草等行业中应用前景广阔。

Abstract:

Abstract: To develop a new type of glycoside flavor, firstly, 2, 3, 4, 6-tetra-O-acetyl-α-D-glucopyranosyl bromide (III) was synthesized from D-glucose. Then, 5-methyl furfuryl alcohol-2, 3, 4, 6-tetra-O-acetyl-β-D-glucoside (IV) was prepared via a glycosylation reaction between Compound III and 5-methyl furfuryl alcohol (II) by the Modified Koenigs-Knorr and Phase transfer catalysis, respectively. Finally, the target compound 5-methyl furfuryl alcohol-β-D-glucoside (V) was obtained by hydrolysis of compound IV. The molecular structures of intermediates and final products were confirmed by 1H NMR, 13C NMR, IR and HRMS. The thermal pyrolysis of glucoside (V) was also studied. The results indicated that: 1) The compound IV synthesized by the two methods was target product, the Modified Koenigs-Knorr method was better than Phase transfer catalysis method. 2) The optimal conditions of the Modified Koenigs-Knorr were determined as follows: n (5-methyl furfuryl alcohol): n (2, 3, 4, 6-tetra-O-acetyl-α-D-glucopyranosyl bromide ) = 1∶1.6, n (5-methyl furfuryl alcohol) : n ( silver carbonate ) =1 : 1.5, refluxing for 4 hours, the yield of compound IV reached 42.9% . 3) The synthesized 5-methyl furfuryl alcohol-β-D-glucoside can release 5- methyl furfural，5- methyl furfuryl alcohol and other aromatic components after pyrolysis, thus holding great promise for applications in the food, tobacco industries.