1256137-84-4

Upstream product

• 2774-19-8 (2R,4aR,6S,7S,8R,8aR)-8-Benzyloxy-6-methoxy-2-phenyl-hexahydro-pyrano[3,2-d][1,3]dioxin-7-ol 
• 81927-55-1 O-benzyl 2,2,2-trichloroacetimidate 
• 100-39-0 benzyl bromide 
• 882980-43-0 2-benzyloxy-1-methylpyridinium triflate 
• 1256137-98-0 C₂₂H₃₂O₇Si 
• 1256137-31-1 methyl 3-O-benzyl-4,6-O-benzylidene-2-O-diazoacetyl-α-D-mannopyranoside 

Relevant academic research and scientific papers

Carbene-Mediated Quaternarization of the Anomeric Position of Carbohydrates: Synthesis of Allylic Ketopyranosides, Access to the Missing α-Gluco and β-Manno Stereoisomers, and Preparation of Quaternary 2-Deoxy 2-Acetamido Sugars

Following our work on the C-H functionalization of carbohydrates by the 1,5 insertion of metal-carbenes, we report herein the robust and scalable conversion of sugar γ-lactones into highly valuable glycosides having a quaternary anomeric position substituted by an allyl chain ready for further functionalization. A divergent synthetic approach furthermore provided a straightforward access to ketopyranosides with a large chemo- and stereodiversity at position 2.

Carbene-mediated functionalization of the anomeric C-H bond of carbohydrates: Scope and limitations

Herein we investigate the scope and limitations of a new synthetic approach towards α- and β-ketopyranosides relying on the functionalization of the anomeric C-H bond of carbohydrates by insertion of a metal carbene. A key bromoacetate grafted at the 2-position is the cornerstone of a stereoselective glycosylation/diazotransfer/quaternarization sequence that makes possible the construction of a quaternary center with complete control of the stereochemistry. This sequence shows a good tolerance toward protecting groups commonly used in carbohydrate chemistry and gives rise to quaternary disaccharides with good efficiency. In the case of a disaccharide with a more restricted conformation, this functionalization process can be hampered by the steric demand next to the targeted anomeric position. In addition, the formation of transient orthoesters during the glycosylation step may also reduce the overall efficiency of the synthetic sequence. Copyright

Rh(II) carbene-mediated synthesis of methyl α- And β-ketopyranosides: Preparation of carbene precursors, quaternarization of the anomeric position, and ring opening of γ-lactones

Methyl α- and β-ketopyranosides were efficiently prepared by carbene-mediated quaternarization of the anomeric position of corresponding aldopyranosides. Preparation of carbene precursors proved to be tedious and required a two-step procedure involving fi