Syntheses of N -aryl-protected glucosamines and their stereoselectivity in chemical glycosylations
作者:Yuji Otsuka、Toshihiro Yamamoto、Koichi Fukase
DOI:10.1016/j.tetlet.2017.06.037
日期:2017.8
to achieve β-selective glycosylation. Various N-aryl aminosugars were synthesized via Buchwald–Hartwig reaction. Glycosylation using glycosyltrichloroacetimidates of N-aryl aminosugars smoothly proceeded in the presence of trimethylsilyl trifluoromethanesulfonate. Use of a glycosyl donor comprising an electron-donating 2,4-dimethoxyphenyl (DMP) group led to the glycosylation proceeding with high β
Introduction of 4-Chlorophenyl: A Protecting Group for the
Hydroxy Function
作者:Koichi Fukase、Yuji Otsuka、Toshihiro Yamamoto
DOI:10.1055/s-0036-1591984
日期:2018.7
and diaryliodonium triflate. This protecting group is stable under the Lewis acidic conditions of glycosylation, but it can be readily removed by the initial conversion into the corresponding 4-methoxyphenyl ether with use of a Pd catalyst, followed by oxidation with ammoniumcerium (IV) nitrate [(NH 4 ) 2 Ce(NO 3 ) 6 ] (CAN).
β‐Selective Glycosylation by Using
<i>O</i>
‐Aryl‐Protected Glycosyl Donors
作者:Yuji Otsuka、Toshihiro Yamamoto、Koichi Fukase
DOI:10.1002/asia.201900700
日期:2019.8
introduced by using the corresponding diaryliodonium triflate. Analysis of the stereoselectivities of several glycosyl donors indicated that the β‐glycosides were obtained through an SN2‐type displacement from the corresponding α‐glycosyl triflate. The NP group could be removed by reduction of the nitro group and acylation, followed by oxidation with ceric ammonium nitrate (CAN).
已开发出包含多个对位取代的O-芳基保护基的新糖基供体,并评估了其对糖基化反应的立体选择性。通过使用受4-硝基苯基(NP)基团保护的硫糖苷,可以实现高度β-选择性糖基化反应,并通过使用相应的三氟甲磺酸二芳基碘铵引入。对几个糖基供体的立体选择性分析表明,β-糖苷是通过从相应的α-糖基三氟甲磺酸酯中以S N 2型取代获得的。可以通过还原硝基和酰化,然后用硝酸铈铵(CAN)氧化来除去NP基团。
[EN] SULFATED OLIGOSACCHARIDES FOR USE IN TREATMENT OF NEURODEGENERATIVE DISEASES<br/>[FR] OLIGOSACCHARIDES SULFATÉS À UTILISER DANS LE TRAITEMENT DE MALADIES NEURODÉGÉNÉRATIVES
申请人:KING S COLLEGE LONDON
公开号:WO2012160337A1
公开(公告)日:2012-11-29
Compounds which interact with HlsTONES Compounds of Formula I : • 4"'-Sulfo-Fucose [alpha]1-3 (4"-sulfo)-Fucose [alpha]1-3 (4'-Sulfo-Fu- cose [alpha]1-4-Glucuronic acid [beta]1-0-Methyl or • 4" "-Sulfo-Fucose [alpha]1-3 (4"-sulfo)-Fucose [alpha]1-3 (4"-sulfo)- Fucose [alpha]1-3 (4'-Sulfo-Fucose [alpha]1-4-Glucuronic acid [be ta]1-0-Methyl. wherein X is sulfate (-SO3H) or phosphate (-PO3H); Su is sulfate and sulfation is most likely at the arrowed positions. The compounds above are useful in the inhibition of histones, in particular histone H1. The compounds can be used in medicine and particularly in the prevention and/or treatment of a wide variety of neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease.
与HlsTONES Formula I 化合物相互作用的化合物包括:• 4"'-糖基硫酸酯 [alpha]1-3 (4"-糖基硫酸酯) [alpha]1-3 (4'-糖基硫酸酯 [alpha]1-4-葡萄糖醛酸 [beta]1-0-甲基或• 4" "-糖基硫酸酯 [alpha]1-3 (4"-糖基硫酸酯) [alpha]1-3 (4"-糖基硫酸酯)- 糖基 [alpha]1-3 (4'-糖基硫酸酯 [alpha]1-4-葡萄糖醛酸 [be ta]1-0-甲基。其中 X 是硫酸酯基 (-SO3H) 或磷酸酯基 (-PO3H);Su 是硫酸酯基,磺酸化最有可能发生在箭头所指位置。上述化合物对于抑制组蛋白,特别是组蛋白 H1,具有用处。这些化合物可用于医药领域,尤其是用于预防和/或治疗多种神经退行性疾病,包括阿尔茨海默病和帕金森病。
Studies on the koenigs-knorr reaction
作者:Marta Dejter-Juszynski、Harold M. Flowers
DOI:10.1016/s0008-6215(00)82857-8
日期:1973.5
Abstract Partial benzylation of methyl 2- O -benzyl-α- L -fucopyranoside afforded a mixture of methyl 2,3-, and 2,4-di- O -benzyl-α- L -fucopyranoside which were separated by means of their monoacetates. Partial benzylation of methylα- L -fucopyranoside gave the 2,4-, and 3,4-dibenzyl ethers in the ratio of 3:2, and no 2,3-isomer could be detected in the reaction mixture. The structures of the three