Glycosyl bromides were prepared in very good yields by bromination of the corresponding anomeric hydroxyl group using a 1 : 1 mixture of triphenyl phosphite and bromine as reagent.
One pot oxidative dehydration - oxidation of polyhydroxyhexanal oxime to polyhydroxy oxohexanenitrile: A versatile methodology for the facile access of azasugar alkaloids
作者:Sandip R. Khobare、Vikas Gajare、E. Vishnuvardhan Reddy、Rajender Datrika、Malavika Banda、Vidavalur Siddaiah、Sharad S. Pachore、Upadhya Timanna、Vilas H. Dahanukar、U.K. Syam Kumar
DOI:10.1016/j.carres.2016.09.003
日期:2016.11
polyhydroxy-oxime (7) to the corresponding ketonitrile (8) in one pot is reported for the first time in carbohydrate literature. Key ketonitrile intermediate (8) upon palladium hydroxide mediated cascade reaction afforded 1-deoxynojirimycin (DNJ) 1b in moderate diastereoselectivity. The cascade reaction involves the conversion of nitrile to amine, heteroannulation, reduction of the imine and subsequent debenzylation
Facile Syntheses of the Trisaccharide Acceptors—The Key Intermediates for Assembling the Elicitor Hexasaccharide
作者:Wei Wang、Fanzuo Kong
DOI:10.1080/00397919908085942
日期:1999.9
A facile synthesis of trisaccharide 7, the key intermediate for assembling phytoalexin glucohexatose elicitor, was achieved via orthoester formation-rearrangement from stepwise coupling of 1,2-O-ethylidene-alpha-D-glucopyranose (2) with 2, 3,4-tri-O-acetyl-6-O-chloroacetyl-alpha-D-glucopyranosyl bromide at 6-position and with acetobromoglucose at 3-position respectively. Similar strategy was used for the synthesis of 14.