Synthesen von Digitoxosyl-Digitoxosiden und Herzglycosid-Tetrasacchariden
作者:Joachim Thiem、Petra Ossowski
DOI:10.1002/jlac.198319831216
日期:1983.12.15
N-Iodsucinimid-Kondensation von D-Digitoxal (1) mit den Monoacetyldigitoxosiden 2 und 3 führt zu α- und β-verknüpften Disacchariden mit interglycosidischen (1 4)- (5 und 9) sowie (1 3)-Bindungen (8 und 12), aus denen sich reduktiv alle möglichen Typen von Digitoxosyl-Digitoxosiden isoliert gewinnen lassen. Durch Umsetzung von 7 zum 3′,4′-Orthoester und nachfolgende Acetylierung sowie Orthoesteröffnung
Oxidative Heck Reaction of Glycals and Aryl Hydrazines: A Palladium-Catalyzed <i>C</i>-Glycosylation
作者:Yaguang Bai、Le Mai Hoang Kim、Hongze Liao、Xue-Wei Liu
DOI:10.1021/jo401032r
日期:2013.9.6
An efficient Heck-type C-glycosylation of glycals via the C-N bond cleavage of aryl hydrazines has been developed. The flexibility of the reaction was tested by the substrate scope, consisting of glycals from different carbohydrate origins as well as aryl hydrazines with various substituents. Pure alpha-C-glycosides were obtained when (3R)-glycals were employed, whereas alpha,beta mixtures were observed with (3S)-glycals.