The influence of boric acid on the acetylation of aldoses: ‘one-pot’ syntheses of penta-O-acetyl-β-D-glucofuranose and its crystalline propanoyl analogue
作者:Richard H. Furneaux、Phillip M. Rendle、Ian M. Sims
DOI:10.1039/b002841j
日期:——
When glucose and boric acid are heated in acetic acid a soluble compound forms from which, with acetic anhydride and catalytic amounts of sulfuric acid, a mixture consisting of >90% of the glucofuranose per-acetates (αâ¶Î² ratio 1â¶1.8) is obtained in high yield. In the absence of the sulfuric acid partial acetylation takes place and penta-O-acetyl-β-D-glucofuranose (αâ¶Î² ratio 1â¶52) is obtainable in good yield by removal of boric acid and completion of the esterification by addition of acetic anhydride and pyridine. A new, crystalline glucofuranose, penta-O-propanoyl-β-D-glucofuranose, is obtained in 58% yield in a âone-potâ procedure using boric acid.
The effects of boric acid on the acid-catalysed acetylation of other aldo-hexoses and -pentoses suggest that the synthesis of furanosyl per-esters could be successful with xylose and idose as well as with glucose.
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Partialsynthese des Strophanthidin-?-D-lyxosids. Glykoside und Aglykone, 87. Mitteilung
作者:K. Reyle、T. Reichstein
DOI:10.1002/hlca.19520350113
日期:1952.2.1
Umsetzung von Strophanthidin (VI) mit amorpher Acetobrom-D-lyxose und Ag2CO3 nach der von Meystre & Miescher angegebenen Variante der Königs-Knorr-Methode und anschliessende Verseifung lieferte krist. Strophanthidin-α-D-lyxosid (IX), das durch ein krist. Triacetat (X) charakterisiert wurde.
根据Meystre&Miescher指定的Koenigs-Knorr方法的一种变体,使trophanthidine(VI)与无定形乙酰溴-D-lyxose和Ag 2 CO 3反应,然后进行皂化,得到晶体。链霉菌素-α-D-lyxoside(IX),由结晶形成。三乙酸酯(X)已被表征。
Convenient syntheses of symmetrical and unsymmetrical glycosyl carbodiimides and N,N-bis(glycosyl)cyanamides
作者:László Kovács、Erzsébet Ősz、Zoltán Györgydeák
DOI:10.1016/s0008-6215(02)00108-8
日期:2002.7
carbon disulfide under mild conditions (room temperature, short reaction time) leads to symmetrical glycosyl carbodiimides. Addition of bis(trimethylsilyl)carbodiimide to peracetylated aldoses under the influence of SnCl(4) afforded N,N-bis(glycosyl)cyanamides for the first time. Readily accessible unsymmetrical N,N'-bis(glycosyl)thioureas can be desulfurated and transformed into the corresponding carbodiimides
A New Synthesis of Ammonium 3-Deoxy-D-<i>manno</i>-octulosonate (Ammonium KDO) from D-Lyxose
作者:B. Giese、T. Linker
DOI:10.1055/s-1992-34178
日期:——
The ammonium salt of 3-deoxy-D-manno-2-octulosonic acid (10) is synthesized from D-lyxose (2) via 1,2,3,4-tetra-O-acetyl-5-bromo-α-D-lyxopyranose (3) and radical C,C-bond formation with tert-butyl 2-(tributylstannylmethyl) propenoate (6). After deprotection and reduction, ozonolysis of 2,3-dideoxy-2-methylene -D-manno-octonic acid (9) yields the target molecule 10.
Benzophenone alpha-d-glycopyranosides, preparation and therapeutic use
申请人:——
公开号:US20030139349A1
公开(公告)日:2003-07-24
The invention concerns (i) [4-(4-cyanobenzyl)phenyl]&agr;-D-glycopyranosides of formula (I) wherein: the group &agr;-D-glycopyranosyl R represents a &agr;-D-glycopyranosyl, &agr;-D-galactopyranosyl. &agr;-D-mannopyranosyl, &agr;-D-arabinopyranosyl, &agr;-D-lyxopyranosyl, or &agr;-D-ribopyranosyl group: (ii) their esters resulting from the esterification of at least a OH function of each pyranosyl group with a C
2
-C
4
alkanoic or a cycloalkanoic acid, as novel industrial products. Said novel [4-(4-cyanobenzyl)phenyl]&agr;-D-glycopyranosides are useful in therapy for fighting against atheromatous plaque.