A palladium-catalyzed glycosylation reaction: the de novo synthesis of natural and unnatural glycosides.
A highly stereoselective and sterospecific palladium-catalyzed glycosylation reaction of a variety of alcohols is reported. The reaction selectively converts alpha-2-substituted 6-carboxy-2H-pyran-3(6H)-ones into alpha-2-substituted 6-alkoxy-2H-pyran-3(6H)-ones with complete retention of configuration and similarly converts the pyranones with beta-carboxy groups into pyranones with beta-alkoxy groups. The reaction works equally well with both amino acid- and carbohydrate-based alcohols. To demonstrate the utility of this process for carbohydrate chemistry several of the products were selectively converted into alpha-manno-pyranosides in two additional steps. Because the 2-substituted 6-carboxy-2H-pyran-3(6H)-ones are prepared by asymmetric synthesis, this reaction can be used for the preparation of either d- or l-pyranones.
Babu
Ravula Satheesh
RS
Department of Chemistry, West Virginia University, Morgantown, West Virginia 26506, USA.
O'Doherty
George A
GA
D000438:Alcohols / Q000737:chemistry; D002384:Catalysis; D006027:Glycosides / Q000138:chemical synthesis*; D006031:Glycosylation; D010165:Palladium / Q000737:chemistry*; D011714:Pyrans / Q000737:chemistry
D000438:Alcohols; D006027:Glycosides; D011714:Pyrans; D010165:Palladium