4692-12-0Relevant articles and documents
Photoinitiated glycosylation at 350 nm
Cumpstey, Ian,Crich, David
experimental part, p. 469 - 485 (2012/06/15)
A method for photochemical activation of glycosyl donors is presented. Selenoglycosides were activated by single-electron transfer using a photooxidant, N-methylquinolinium hexafluorophosphate, as photosensitizer and a toluene cosolvent as cosensitizer under irradiation at 350 nm. In this way we were able to synthesize glycosides including (1→6)-linked disaccharides. Benzyl ethers and benzoate esters were compatible with these conditions, allowing potentially synthetically useful transformations. The major by-products were due to hydrolysis; the reactions required the presence of oxygen and were run in air.
Carbohydrate Homologation by the Use of 2-(Trimethylsilyl)thiazole. Preparative Scale Synthesis of Rare Sugars: L-Gulose, L-Idose, and the Disaccharide Subunit of Bleomycin A2
Dondoni, Alessandro,Marra, Alberto,Massi, Alessandro
, p. 6261 - 6267 (2007/10/03)
The well established one-carbon homologation method of protected monosaccharides employing 2-(trimethylsilyl)thiazole (2-TST) as a formyl anion equivalent has been used for high yield and multigram scale synthesis of the title rare hexoses from L-xylose. Thus, L-gulose has been obtained by stereoselective anti-addition of 2-TST to aldehydo-L-xylose diacetonide followed by thiazole to formyl conversion of the resulting alcohol. The inversion of configuration at C-1 of this alcohol by an oxidation - reduction sequence prior to the aldehyde releasing from thiazole led to L-idose. The same alcohol was readily elaborated into 1,3,4,6-tetra-O-acetyl-L-gulopyranose whose highly stereoselective glycosidation coupling with 3-O-carbamoyl-2,4,6-tri-O-acetyl-α-D-mannosyl diethyl phosphate afforded the same peracetylated disaccharide subunit employed by Boger and Honda in the total synthesis of the antibiotic bleomycin A2.
An electrochemical synthesis of methyl α-isomaltoside
Hamann, Carl Heinz,Polligkeit, Herbert,Wolf, Peter,Smiatacz, Zygfryd
, p. 1 - 8 (2007/10/02)
A novel approach has been developed for the synthesis of methyl α-isomaltoside (10), comprising, as the first step, electrochemical conversion of the hydroxyl groups of methyl α-D-glucopyranoside into the corresponding anions.The anions subsequently react with tetra-O-acetyl-α-D-glucopyranosyl bromide to give methyl 2',3',4',6'-tetra-O-acetyl-α-isomaltoside (8) as the main product.O-deacetylation of which affords 10.The glycosidation proceeds under complete stereochemical control.Keywords: Isomaltoside, methyl α-; Disaccharides; Electrochemical synthesis; Structure