Stereospecific synthesis of β-D-fructofuranosides using thioglycoside donors and internal aglycon delivery
Stereospecific synthesis of β-D-fructofuranosides using thioglycoside donors and internal aglycon delivery
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DOI：
10.1021/jo970983r
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发表时间：
1998-03-20
影响因子：
3.6
通讯作者：
Oscarson, S
中科院分区：
文献类型：
--
作者：
Krog-Jensen, C;Oscarson, S
立体特异性合成β - d -果糖呋喃苷已完成应用内受体递送方法。乙醇或单糖,承兑人是最初拴在fructofuranose 3-hydroxyl集团,毗邻异头中心和beta-side的呋喃糖环,作为混合p-methoxybenzaldehyde缩醛的一部分,由DDQ-oxidation乙1,4,6-tri-O-benzyl-3-O——(4-methoxybenzyl) 2-thio-d-fructofuranoside p-methoxybenzylated的受体或受体的存在的相应3-OH呋喃果糖苷。然后，用亲硫启动子激活巯基糖苷，允许受体从缩醛传递到活化的端粒中心，以高产率（76-85%）生成β -连接的果糖呋喃苷。如果使用非亲核阴离子（三氟酸盐，高氯酸盐）的启动子，中间缩醛分解生成β -果糖呋喃苷产品作为3-OH衍生物。然而，如果使用NIS作为启动子，n -琥珀酰亚胺阴离子与苄基碳相互作用，得到β -果糖呋喃苷产物，即混合果糖呋喃苷-3- o -酰基n -琥珀酰亚胺对甲氧基苯甲醛缩醛。
Stereospecific synthesis of beta-D-fructofuranosides has been accomplished by the application of an internal acceptor delivery approach. The acceptor, ethanol or monosaccharides, is initially tethered to the fructofuranose 3-hydroxyl group, adjacent to the anomeric center and on the beta-side of the furanose ring, as part of a mixed p-methoxybenzaldehyde acetal, which is formed by DDQ-oxidation of ethyl 1,4,6-tri-O-benzyl-3-O-(4-methoxybenzyl)-2-thio-D-fructofuranoside in the presence of the acceptor or of the p-methoxybenzylated acceptor in the presence of the corresponding 3-OH fructofuranoside. Then, activation of the thioglycoside with a thiophilic promoter allows the delivery of the acceptor from the acetal to the activated anomeric center to yield the beta-linked fructofuranoside in high yields (76-85%). If promoters with nonnucleophilic anions (triflate, perchlorate) are used, the intermediate acetal decomposes to produce the beta-fructofuranoside products as 3-OH derivatives. However, if NIS is used as promoter, the N-succinimide anion interacts with the benzylidene carbon to give the beta-fructofuranoside products as mixed fructofuranoside-3-O-yl N-succinimide p-methoxybenzaldehyde acetals.