857892-46-7

Upstream product

• 19879-84-6 2,3,4,6-tetra-O-acetyl-1-thio-D-galactopyranose 
• 1246854-84-1 2,3,4,6-tetra-O-benzoyl-1-S-acetyl-1-thio-β-D-galactopyranose 
• 2592-58-7 1,2,3,4,6-penta-O-benzoyl-α-D-galactopyranoside 
• 10257-28-0 D-Galactose 
• 98-88-4 benzoyl chloride 
• 857892-36-5 triphenylmethyl 2,3,4,6-tetra-O-acetyl-1-thio-β-D-galactopyranoside 
• 857892-39-8 triphenylmethyl 2,3,4,6-tetra-O-benzoyl-1-thio-β-D-galactopyranoside 

Relevant academic research and scientific papers

Practical synthesis of latent disarmed S-2-(2-propylthio)benzyl glycosides for interrupted Pummerer reaction mediated glycosylation

Practical synthetic methods to latent disarmed S-2-(2-propylthio)benzyl (SPTB) glycosides for interrupted Pummerer reaction mediated glycosylation have been discovered. Among them, both coupling reaction of PTB-Cl with glycosyl thiols and BF3·OEt2 promoted reaction of peracylated glycosides with PTB-SH produced peracylated SPTB glycosides in large scales and with high efficiency.

Stereoselective Epimerizations of Glycosyl Thiols

Glycosyl thiols are widely used in stereoselective S-glycoside synthesis. Their epimerization from 1,2-trans to 1,2-cis thiols (e.g., equatorial to axial epimerization in thioglucopyranose) was attained using TiCl4, while SnCl4 promoted their axial-to-equatorial epimerization. The method included application for stereoselective β-d-manno- and β-l-rhamnopyranosyl thiol formation. Complex formation explains the equatorial preference when using SnCl4, whereas TiCl4 can shift the equilibrium toward the 1,2-cis thiol via 1,3-oxathiolane formation.

Synthesis methods of glycosyl mercaptan and auranofin

The present invention discloses synthesis methods of glycosyl mercaptan and auranofin. The glycosyl mercaptan synthesis method comprises: (1) dissolving sulfur acetyl protecting saccharide, mercaptan and a weak alkali in an organic solvent to obtain a raw material mixing liquid; and (2) carrying out a reaction on the raw material mixing liquid for 1-24 h at a room temperature, and carrying out extraction purification on the reaction product to obtain the glycosyl mercaptan. The auranofin synthesis method comprises: A, dissolving 2,3,4,6-tetra-O-acetyl-beta-D-glucopyranosyl mercaptan and triethyl phosphorus gold trichloride in an organic solvent, carrying out an ice bath, adding an aqueous solution of an alkali metal weak acid salt, and continuously stirring to obtain a reaction liquid; and B, carrying out a nucleophilic substitution reaction on the reaction liquid at a room temperature to obtain a crude reaction product, and carrying out extraction purification to obtain the pure auranofin. The method of the present invention has characteristics of mild reaction condition, high yield, good adaptability, and low production cost.

SnCl4- and TiCl4-catalyzed anomerization of acylated O - And S -glycosides: Analysis of factors that lead to higher α: β d reaction rates

The quantification of factors that influence both rates and stereoselectivity of anomerization reactions catalyzed by SnCl4 and TiCl4 and how this has informed the synthesis of α-O- and α-S-glycolipids is discussed. The SnCl4-catalyzed anomerization reactions of β-S- and β-O-glycosides of 18 substrates followed first order equilibrium kinetics and kf + kr values were obtained, where kf is the rate constant for the forward reaction (β → α) and kr is the rate constant for the reverse reaction (α → β). Comparison of the kf + k r values showed that reactions of glucuronic acid or galacturonic acid derivatives were ～10 to 3000 times faster than those of related glucoside and galactopyranoside counterparts and α:β ratios were generally also higher. Stereoelectronic effects contributed from galacto-configured compounds were up to 2-fold faster than those of corresponding glucosides. The introduction of groups, including protecting groups, which are increasingly electron releasing generally led to rate enhancements. The anomerization of S-glycosides was consistently faster than that of corresponding O-glycosides. Reactions were generally faster for reactions with TiCl4 than those with SnCl4. Anomeric ratios depended on the Lewis acid, the number equivalents of the Lewis acid, temperature, and substrate. Very high ratios of α-products for both O- and S-glucuronides were observed for reactions promoted by TiCl4; for these substrates TiCl4 was superior to SnCl4. Anomeric ratios from anomerization of S-glucosides were higher with SnCl4 than with TiCl4. The dependence of equilibrium ratio on Lewis acid and the number of equivalents of Lewis acid indicated that the equilibrium ratio is determined by a complex of the saccharide residue bound to the Lewis acid and not the free glycoside. The high α:β ratios observed for anomerization of both O- and S-glycuronic acids can be explained by coordination of the C-1 heteroatom and C-6 carbonyl group of the product to the Lewis acid, which would enhance the anomeric effect by increasing the electron-withdrawing ability of the anomeric substituent and lead to an increase in the proportion of the α-anomer. Such an observation would argue against the existence of a reverse anomeric effect. Support for a chelation-induced endocyclic cleavage mechanism for the anomerization is provided by the trapping of a key intermediate. The data herein will help predict the tendency of β-glycosides to undergo anomerization; this includes cases where 1,2-trans glycosides are initial products of glycosidation reactions catalyzed by TiCl4 or SnCl4.

2-Haloethyl 1-thioglycosides as new tools in glycoside syntheses. Part 1: Preparation, characteristics, general reactions

2-Haloethyl 1-thioglycosides are excellent leaving groups when the 2-haloethyl function is activated with silver salts or Lewis acids. These thioglycosides can be synthesized on the original Cerny route or for better compatibility with the needs of a more complex glycoside synthesis, in stepwise procedures via 2-(2-tetrahydropyran-2-yloxy)ethyl glycosides or trityl 1-thioglycosides. The initial step in glycosidation reaction presumably proceeds via a thiiranium ion, which is responsible for their increased reactivity compared with normal thioethers as leaving groups in glycoside syntheses. Basic features of this new system with respect to reactivity and selectivity in disaccharide syntheses are described.