Mirror-image carbohydrates: synthesis of the unnatural enantiomer of a blood group trisaccharide.
Methyl D-glucoside and d-glucose pentaacetate are transformed, respectively, into methyl alpha-O-glucuronide 3 and hydroxymethyl beta-C-glucuronide 9, which undergo decarboxylative elimination efficiently to produce 4-deoxypentenoside 4 and L-glucal 10. These unsaturated pyranosides provide an expeditious entry into mirror-image oligosaccharides, as demonstrated in the synthesis of the unnatural enantiomer of the H-type II blood group determinant trisaccharide (D-Fuc-(alpha1-->2)-L-Gal-(beta1-->4)-L-GlcNAc-beta-OMe). This work illustrates that D-glucose, a common starting material in the synthesis of naturally occurring carbohydrates, can also be used to prepare their mirror-image analogues.
Boulineau
Fabien P
FP
Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907-2084, USA.
Wei
Alexander
A
D000017:ABO Blood-Group System; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000138:chemical synthesis*; D003837:Deoxy Sugars / Q000138:chemical synthesis; D006027:Glycosides / Q000138:chemical synthesis; D008969:Molecular Sequence Data; D015394:Molecular Structure; D013237:Stereoisomerism; D014312:Trisaccharides / Q000138:chemical synthesis*
D000017:ABO Blood-Group System; D002241:Carbohydrates; D003837:Deoxy Sugars; D006027:Glycosides; D014312:Trisaccharides