383905-62-2Relevant academic research and scientific papers
Neighboring group participation in glycosylation reactions by 2,6-disubstituted 2-O-benzoyl groups: A mechanistic investigation
Williams, Rohan J.,McGill, Nathan W.,White, Jonathan M.,Williams, Spencer J.
experimental part, p. 236 - 263 (2011/04/22)
Variable yields and glycosylation stereoselectivity were obtained for NIS/TfOH-medi- ated reaction of 4-methoxyphenyl 2,4,6-tetra-O-acetyl-β-D- galactopyranoside and thiogalactosides bearing acetyl, benzoyl, 2,6-dimethoxylbenzoyl, 2,4,6-trimethylbenzoyl, or 2,6-dichlorobenzoyl groups at the 2-positions and acetyl at the remainder. X-ray structures of 4-methylphenyl 2,3,4,6-tetra-O-(2,4,6-trimethylbenzoyl)-1-thio-β-D-galactopyr anoside and 4-methylphenyl 3,4-O-isopropylidene-2,6-di-O-(2,4,6-trimethylbenzoyl)-1-thio- β-D-galactopyranoside revealed slightly distorted 4C1 chair conformations. Variable temperature NMR revealed that activation of 4-methylphenyl 2,3,4,6-tetra-O-(2,4,6-trimethylbenzoyl)-1-thio-β-D- galactopyranoside afforded only dioxolenium ion, whereas 4-methylphenyl 3,4,6-tri-O-acetyl-2-O-(2,4,6-trimethylbenzoyl)-1-thio-β-D- galactopyranoside gave a 1:1 mixture of dioxolenium ion and glycosyl triflate. However, the reaction intermediates formed from these deactivated donors do not influence the glycosylation stereoselectivity; instead, it is influenced by steric and electronic interactions at the transition states. Copyright Taylor & Francis Group, LLC.
2,6-Disubstituted benzoates as neighboring groups for enhanced diastereoselectivity in β-galactosylation reactions: Synthesis of β-1,3-linked oligogalactosides related to arabinogalactan proteins
McGill, Nathan W.,Williams, Spencer J.
experimental part, p. 9388 - 9398 (2010/03/04)
(Chemical Equation Presented) Arabinogalactan proteins (AGPs) are plant glycoproteins which contain a β-1,3-linked galactan core. The synthesis of the β-galactopyranose-1,3-β-galactopyranose linkage using various 2-O-acyl-protected glycosyl donors has bee
Remarkable solvent effect on Pd(0)-catalyzed deprotection of allyl ethers using barbituric acid derivatives: Application to selective and successive removal of allyl, methallyl, and prenyl ethers
Tsukamoto, Hirokazu,Suzuki, Takamichi,Kondo, Yoshinori
, p. 3131 - 3136 (2008/09/19)
Pd(0)-catalyzed deprotection of allyl ethers using barbituric acid derivatives in protic polar solvent such as MeOH and aqueous 1,4-dioxane proceeds at room temperature without affecting a wide variety of functional groups. Control of the reaction temperature allows selective and successive cleavage of allyl, methallyl, and prenyl ethers. A study of ligand effects on the deprotection reveals that the improved reactivity in MeOH results from the accelerated oxidative addition to Pd(O). Georg Thieme Verlag Stuttgart.
Synthesis of a divalent glycoside of an α-galactosyl disaccharide epitope involved in the hyperacute rejection of xenotransplantation
Lu, Yi-Pin,Li, Hui,Cai, Meng-Shen,Li, Zhong-Jun
, p. 289 - 294 (2007/10/03)
3,6-Dioxaoct-1,8-diyl di-(3-O-α-D-galactopyranosyl-β-D-galactopyranoside) was synthesized for use in research on hyperacute rejection of xenotransplantation. The trichloroacetate method was successfully applied to form stereoselectively the α-D-galactosyl
