2-ulosyl bromides

Lichtenthaler, F. W. Sclmeideradams, T., 3,4,6-Tri-O-Benzyl-Alpha-D-Arabino-Hexopyranos-2-Ulosyl Bromide - a Versatile Glycosyl Donor for the Efficient Generation of Beta-D-Mannopyranosidic Linkages. J. Org. Chem. 1994,59, 6728-6734. 

An example of a sugar-derived chiral -haloketone is offered by 24. When ulosyl bromide 24 is coupled to acetaldehyde in a Grignard-type process, a mixture of isomeric adducts is formed, where the 50% is represented by 25, possessing the (R) configuration at the hydroxy ethyl substituent (equation 21). The same protocol is applied in an efficient nucleophilic C-glycosidation reaction of 24 with galactose-derived aldehyde 26 to give 27 (equation 22)20. 

Anomeric C-homologation can be effected by applying Reformatsky conditions, zinc promoted addition to aldehydes smoothly providing C-glycosiduloses of type 6 (35, 36). The synthetic potential of ulosyl bromides... 

F. W. Lichtenthaler, U. Klares, Z. Szurmai, and B. Wemer, 4,6-di-0-benzoyl-3-0-benzyl-a-D-ara-bino-hexo-pyranos-2-ulosyl bromide A conveniently accessible glycosyl donor for the expedient construction of diantennary /j-D-mannosides branched at 0-3 and 0-6, Carbohydr. Res., 305 (1997) 293-303. 

F. W. Lichtenthaler and T. Schneider-Adams, 3,4,6-Tri-0-benzyl-a-D-arabmohexopyranos-2-ulosyl bromide - A versatile glycosyl donor for the efficient generation of /i-D-mannopyranosidic linkages, J. Org. Chem., 59 (1994) 6728-6734. 

Generation of the P-D-mannopyranosidic linkage via Ag /Si02-Al203 activation of 2-ulosyl bromides [36]. 

Tribenzoyl 3,4,6-Tri-O-benzoyl-a-D-Atabino-hexopyranos-2-ulosyl bromide [82469-69-0]... 

Treatment of suitable free sugars with triphenylphosphite and bromine has afforded the corresponding glycosyl bromides in good yield, and hexopyranos-2-ulosyl bromides have been prepared from 2-hydroxyglucal derivatives using NBS. These products have been employed in... 

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