title: Extended Alkenyl Glycosides by Ruthenium-Catalyzed Cross-Metathesis Reaction and Application toward Novel C-Linked Pseudodisaccharides.
abstract: Grubbs's ruthenium benzylidene catalyst (3) has been successfully applied toward the cross-metathesis reactions of allyl alpha-D-galactopyranoside derivative (4) with a number of olefins. Terminal alkenes possessing a wide range of protecting groups were used as cross-metathetic partners to allow syntheses of glycosides having extended spacers and functionality in the aglycon moieties. The reaction is quite general and the cross-metathesis products (14-21) were obtained in high yields. The strategy has also been applied toward the synthesis of some C-linked pseudodisaccharides from allyl alpha-C-galactoside derivatives (23, 26, and 28) in good yields. In almost all cases, trans-stereoselectivity was found to be good to excellent.
authors.affiliation: Department of Chemistry, University of Ottawa,Ottawa, Ontario, Canada K1N 6N5.
authors.forename: René
authors.initials: R
authors.lastname: Roy
authors.forename: Romyr
authors.initials: R
authors.lastname: Dominique
authors.forename: Sanjoy K.
authors.initials: SK
authors.lastname: Das