82295-98-5

Upstream product

• 136656-49-0 3,4-di-O-acetyl-1,5-anhydro-6-O-t-butyldimethylsilyl-2-deoxy-D-arabino-hex-1-enitol 
• 2873-29-2 D-glucal triacetate 
• 58871-09-3 6-O-tert-butyldimethylsilyl-D-glucal 
• 13265-84-4 D-glucal 
• 118356-98-2 4,6-di-O-acetyl-3-O-D-glucal 
• 50-99-7 D-glucose 
• 69534-73-2 3,4,6-O-tri-O-acetyl-D-glucal 

Downstream Products

• 18546-25-3 6-O-p-tolylsulfonyl-3,4-di-O-acetyl-D-glucal 
• 307991-11-3 1,6-anhydro-2,3-dideoxy-β-D-erythro-hex-2-enopyranose 
• 136656-49-0 3,4-di-O-acetyl-1,5-anhydro-6-O-t-butyldimethylsilyl-2-deoxy-D-arabino-hex-1-enitol 

Relevant academic research and scientific papers

Zirconium-Catalyzed Hydroalumination of C=O Bonds: Site-Selective De- O-acetylation of Peracetylated Compounds and Mechanistic Insights

An unprecedented hydroalumination of C = O bonds catalyzed by zirconocene dichloride is reported herein and applied to the site-selective deprotection of peracetylated functional substrates. A mixed metal hydride, with 1:1 zirconium/aluminum stoichiometry

Diastereoselective Synthesis of Thioglycosides via Pd-Catalyzed Allylic Rearrangement

Stereoselective glycosylation is challenging in carbohydrate chemistry. Herein, stereoselective thioglycosylation of glycals via palladium-catalyzed allylic rearrangement yields various substituents on α-isomer thioglycosides. Two comprehensive series of aryl and benzyl thioglycosides were obtained via a combination of thiosulfates with glycals derived from glucose, arabinose, galactose, and rhamnose. Furthermore, diosgenyl α-l-rhamnoside and isoquercitrin achieved selectivity via stereospecific [2,3]-sigma rearrangements of α-sulfoxide-rhamnoside and α-sulfoxide-glucoside, respectively.

Carbocyclic Substrate Analogues Reveal Kanosamine Biosynthesis Begins with the α-Anomer of Glucose 6-Phosphate

NtdC is an NAD-dependent dehydrogenase that catalyzes the conversion of glucose 6-phosphate (G6P) to 3-oxo-glucose 6-phosphate (3oG6P), the first step in kanosamine biosynthesis in Bacillus subtilis and other closely-related bacteria. The NtdC-catalyzed r

Regio- A nd chemoselective deprotection of primary acetates by zirconium hydrides

A combination of DIBAL-H and Cp2ZrCl2 is shown to promote the regioselective cleavage of primary acetates on a broad scope of substrates, ranging from carbohydrates to terpene derivatives, with a high tolerance toward protecting groups and numerous functionalities found in natural products and bioactive compounds. Apart from providing highly valuable building blocks in only two steps from biosourced raw materials, this selective de-O-acetylation should also be strongly helpful to solve selectivity issues in organic synthesis.

Solid-surface activated recombinant: Rhizopous oryzae lipase expressed in Pichia pastoris and chemically modified variants as efficient catalysts in the synthesis of hydroxy monodeprotected glycals

Lipase of Rhizopus oryze expressed in Pichia pastoris (ROLpp) was selectively immobilized on octyl-Sepharose, fixing the open and active conformations. This enzyme was compared to the commercial one (ROLsigma) and a unique enzyme of 32 kDa was selectively adsorbed in both cases. Small differences in the N-terminal peptide sequence of both lipases seem to be involved in the enzyme fixing on the solid support, affecting the active site structure. This phenomenon resulted in a strong difference in catalytic properties between immobilized enzymes, with ROLpp being the most active, specific and regioselective heterogeneous biocatalyst in the hydrolysis of lactal hexaacetate. Immobilized ROLpp was 8 times more active, and more specific than immobilized ROLsigma, with excellent regioselectivity (monodeprotection in 3-OH, >99% yield). Solid-phase chemical modification of the N-terminus of immobilized ROLpp was attempted because of the moderate results obtained in the hydrolysis of glucal triacetate. Different biomolecules were introduced and the enzyme catalytic properties in this reaction were assessed. The modification of ROLpp with a polycarboxylated peptide (pA) improved the activity, specificity and regioselectivity of the enzyme, producing mainly the 3-OH monodeprotected glucal. The presence of acetonitrile 3% (v/v) in the reaction medium negatively affected ROLpp, being completely unspecific, whereas ROLpp modified with p1 conserved the specificity and regioselectivity shown in fully aqueous medium. The presence of dioxane improved the specificity and varied the regiopreference of the immobilized lipase (from C-3 to C-6 and C-4 monohydrolyzed products). The posterior modification with pA improved the specificity and the regio-preference of ROLpp towards C-6 monohydrolyzed product.

Low ionic liquid concentration in water: A green and simple approach to improve activity and selectivity of lipases

The activity of several commercial and genetically engineered lipases, already immobilized on octyl-Sepharose, in aqueous solutions containing ionic liquids (ILs) in a molar concentration of 0.01 mol L-1 was investigated. Strong variations in t

Escherichia coli LacZ β-galactosidase inhibition by monohydroxy acetylated glycopyranosides: Role of the acetyl groups

Escherichia coli LacZ β-galactosidase is an extensively employed glycosidase for many different scientific purposes. Here, we describe how acetyl moieties protecting hydroxyl groups of the glycosides make these molecules better inhibitors to the enzyme activity. In particular, the presence of a unique hydroxyl group in the peracetylated glycosides still enhanced the inhibitory capacity of the molecule more. Molecular docking studies showed that the acetylation in the carbohydrate structure helps the substrate to accommodate into the active site. From a small biocatalytic synthesized library of different monohydroxy acetylated glycosides we can conclude that galactosidic structures are better for inhibition capacity. The best inhibitors were two monohydroxy lactal derivatives. The one with the OH free, in C-6 of the galactosidic part of the disaccharide, was a better inhibitor (Ki of 95 μM) than that with the OH free in C-3 in the glucosidic part of the molecule (Ki of 143 μM).

Pseudo enantiomeric carbohydrate olefin ligands - Case study and application in kinetic resolution in rhodium(I)-catalysed 1,4-addition

In order to investigate significant differences in asymmetric induction for pseudo enantiomeric carbohydrate olefin ligands in rhodium(I)-catalysed 1,4-addition reactions, we designed a set of new olefin ligands differing in relative configuration and pyranoside conformation. With these, we have successfully elucidated structural requirements for metal binding and also identified an improved alternative for one pseudo enantiomer. Furthermore, we report the efficient kinetic resolution of a racemic 4-hydroxycyclopentenone derivative by 1,4-addition.

PROCESS FOR THE PREPARATION OF 3.6-DI-O-ACETYL-D-GLYCALS

There is described a process for the preparation of 3,6-di-O-acetyl-D-glycals by C4->C6 acyl migration by treatment of corresponding 3,4-di-O-acetyl-D-glycals with a buffer at pH of from 8.6 to 9.5. The starting 3,4-di-O-acetyl-D-glycals may be prepared in situ by enzymatic hydrolysis of corresponding peracetylated D-glycals in a buffer at a pH of from 3 to 5.

Preparation of linear oligosaccharides by a simple monoprotective chemo-enzymatic approach

A monoprotective approach, involving acetyl ester as unique protective group in oligosaccharides synthesis, has been developed. Starting from peracetylated monosaccharides and glycals, by using an efficient and selective chemo-enzymatic 'one-pot' strategy (a regioselective hydrolysis catalyzed by immobilized lipases followed by a chemical acyl migration), different carbohydrate acceptors, only protected with acetyl ester, can be achieved. If combined with the use of an acetylated glycosyl donor, the glycosylation reaction with these glycosyl acceptors leads to peracetylated oligosaccharides. These compounds can be directly used as intermediates for the synthesis of glycopeptides used as antitumoral vaccines and, at the end of the process, can be easily fully deprotected in only one step. Thus, these key building blocks have been successfully used in glycosylation reactions for an efficient construction of peracetylated disaccharides, such as the biological relevant lactosamine, in multigram scale. Subsequently, glycosylation with the 3OH-tetraacetyl-α-d-galactose, used as carbohydrate acceptor, allowed the synthesis of a peracetylated N-trisaccharidic precursor of the lacto-N-neo-tetraose antigen. Extending this strategy to a 3OH-di-acetyl galactal, one peracetylated precursor of the T tumor-associated carbohydrate antigen has been synthesized. This efficient approach, characterized by the use of the acetyl ester as only protecting group during all the synthetical steps expected, represents an easy and efficient alternative to the classical synthetic methods in carbohydrate chemistry that involve several protecting group manipulation.