[EN] A NOVEL SYNTHETIC NEISSERIA MENINGITIDIS SEROGROUP A OLIGOMER AND PROCESS FOR SYNTHESIZING THEREOF [FR] NOUVEL OLIGOMÈRE SYNTHÉTIQUE DE NEISSERIA MENINGITIDIS DE SÉROGROUPE A ET SON PROCÉDÉ DE SYNTHÈSE
[EN] A NOVEL SYNTHETIC NEISSERIA MENINGITIDIS SEROGROUP A OLIGOMER AND PROCESS FOR SYNTHESIZING THEREOF [FR] NOUVEL OLIGOMÈRE SYNTHÉTIQUE DE NEISSERIA MENINGITIDIS DE SÉROGROUPE A ET SON PROCÉDÉ DE SYNTHÈSE
Regioselective lipase-catalysed acylation of 4,6-O-benzylidene-α- and-β-d-pyranoside derivatives displaying a range of anomeric substituents
作者:Jonathan J. Gridley、Andrew J. Hacking、Helen M.I. Osborn、David G. Spackman
DOI:10.1016/s0040-4020(98)00935-1
日期:1998.12
The application of Lipase enzymes to effect regioselective C-3-O-acylation of - and -galactopyranosides displaying a range of anomeric substituents, and C-2-O-acylation of phenyl and ethyl is reported. In particular this method has allowed introduction of a variety of acyl protecting groups at the C-3 hydroxyl group of ethyl 11.
Direct Synthesis of Diastereomerically Pure Glycosyl Sulfonium Salts
作者:Laurel K. Mydock、Medha N. Kamat、Alexei V. Demchenko
DOI:10.1021/ol2009818
日期:2011.6.3
glycosyl sulfonium salts can be generated via direct anomeric S-methylation of ethylthioglycosides. Mechanistically, this pathway represents the first step in the activation of thioglycosides for glycosidation; however, it can further allow for the synthesis and isolation of quasi-stable sulfonium ions, representing a new approach for studying these key intermediates.
The invention provides a method for forming P-glucoside linkages in carbohydrate polymers, particularly synthetic glucan molecules, by attaching a protecting group to the C2 position of a glucoside donor. The protecting group of the invention stabilizes the dioxolenium ion and prevents orthoester formation to promote the β linkage and inhibit the undesirable a linkage. One such protecting group is 4-acetoxy-2,2-dimethylbutanoyl chloride.
2,3-Di-O-picolinyl building blocks as glycosyl donors with switchable stereoselectivity
作者:Jagodige P. Yasomanee、Archana R. Parameswar、Papapida Pornsuriyasak、Nigam P. Rath、Alexei V. Demchenko
DOI:10.1039/c6ob00107f
日期:——
2-O-Picolinyl protected glycosyldonors lead to the formation of 1,2-trans glycosides with complete stereoselectivity. This is due to the participatory effect of the picolinyl nitrogen that is able to block the bottom face of the ring via a six-membered cyclic intermediate. Herein we demonstrate that if the nitrogen atom of the O-picolinyl moiety is temporarily blocked by coordination to the metal
2- O-吡啶甲酸保护的糖基供体导致形成具有完全立体选择性的1,2-反式糖苷。这归因于吡啶甲基氮的参与作用,该吡啶甲氮能够通过六元环状中间体阻断环的底面。本文证明,如果O- picolinyl部分的氮原子通过与金属中心(Pd)的配位而暂时被封闭,则无法参与糖基化,因此2 - O -picolinyl辅助糖基化的立体选择性可以为“切换”。
Site‐ and Stereoselective Phosphoramidation of Carbohydrates Using a Chiral Catalyst and a Chiral Electrophile
作者:Daniel A. Glazier、John M. Schroeder、Stephanie A. Blaszczyk、Weiping Tang
DOI:10.1002/adsc.201900382
日期:2019.8.21
phosphorus center. As such, the site‐ and stereoselective phosphoramidation of carbohydrates has never been achieved. We have developed the first site‐ and stereoselective phosphoramidation reaction of carbohydrates using a chiral catalyst and a chiral electrophile. This method offers a convenient solution for the selective synthesis of phosphoramidated carbohydrate‐containing prodrugs and natural products