73415-92-6Relevant academic research and scientific papers
β-Mannosylation through O-Alkylation of Anomeric Cesium Alkoxides: Mechanistic Studies and Synthesis of the Hexasaccharide Core of Complex Fucosylated N-Linked Glycans
Bhetuwal, Bishwa Raj,Fang, Cheng,Li, Xiaohua,Liu, Peng,Meng, Shuai,Nguyen, Hai,Qi, Xiaotian,Saybolt, Kevin,Zhu, Jianglong
supporting information, p. 2291 - 2301 (2020/04/30)
Several structurally diverse d-mannose-derived lactols, including various deoxy-d-mannoses and conformationally restricted bicyclic d-mannoses, have been synthesized and investigated in mechanistic studies of β-mannosylation through Cs2CO3-mediated anomeric O-alkylation. It was found that deoxy mannoses or conformationally restricted bicyclic d-mannoses are not as reactive as their corresponding parent mannose. This type of β-mannosylation proceeds efficiently when the C2-OH is left free, and protection of that leads to inferior results. NMR studies of d-mannose-derived anomeric cesium alkoxides indicated the predominance of the equatorial β-anomer after deprotonation. Reaction progress kinetic analysis suggested that monomeric cesium alkoxides be the key reactive species for alkylation with electrophiles. DFT calculations supported that oxygen atoms at C2, C3, and C6 of mannose promote the deprotonation of the anomeric hydroxyl group by Cs2CO3 and chelating interactions between Cs and these oxygen atoms favor the formation of equatorial anomeric alkoxides, leading to the highly β-selective anomeric O-alkylation. Based on experimental data and computational results, a revised mechanism for this β-mannosylation is proposed. The utilization of this β-mannosylation was demonstrated by an efficient synthesis of the hexasaccharide core of complex fucosylated N-linked glycans.
Stereoselective β-mannosylation via anomeric O-alkylation: Formal synthesis of potent calcium signal modulator acremomannolipin A
Li, Xiaohua,Berry, Nader,Saybolt, Kevin,Ahmed, Uddin,Yuan, Yue
, p. 2069 - 2072 (2017/05/04)
Stereoselective β-mannosylation has been investigated via cesium carbonate-mediated anomeric O-alkylation of D-mannose-derived lactol with various electrophiles. It was found that electrophiles bearing trifluoromethanesulfonate (triflate) as the leaving g
Synthesis of a beta1,2-mannopyranosyl tetrasaccharide found in the phosphomannan antigen of Candida albicans.
Nitz,Purse,Bundle
, p. 2939 - 2942 (2007/10/03)
The synthesis of a portion of the challenging beta1,2-mannosyl polymer found in the cell walls of Candida albicans was undertaken to develop a conjugate vaccine against C. albicans and to facilitate NMR conformational studies of this unique polysaccharide
Stereoselective, Lewis acid-catalyzed glycosylation of alcohols by glucose 1,2-cyclic sulfites
Sanders, William J.,Kiessling, Laura L.
, p. 7335 - 7338 (2007/10/02)
α-D-Glucopyranose-1,2-cyclic sulfites (1a-c) have been prepared by reaction of a suitably protected glucose residue and thionyl diimidazole. Reaction of these compounds with alcohols in the presence of Yb(OTf)3 or Ho(OTf)3 stereosele
