84926-76-1Relevant academic research and scientific papers
Total Synthesis of Phospholipomannan of Candida albicans
Ali, Asif,Gannedi, Veeranjaneyulu,Singh, Parvinder Pal,Vishwakarma, Ram A.
, p. 7757 - 7771 (2020/07/25)
First, total synthesis of the cell surface phospholipomannan anchor [β-Manp-(1 → 2)-β-Manp]n-(1 → 2)-β-Manp-(1 → 2)-α-Manp-1 → P-(O → 6)-α-Manp-(1 → 2)-Inositol-1-P-(O → 1)-phytoceramide of Candida albicans is reported. The target phospholipomannan (PLM) anchor poses synthetic challenges such as the unusual kinetically controlled (1 → 2)-β-oligomannan domain, anomeric phosphodiester, and unique phytoceramide lipid tail linked to the glycan through a phosphate group. The synthesis of PLM anchor was accomplished using a convergent block synthetic approach using three main appropriately protected building blocks: (1 → 2)-β-tetramannan repeats, pseudodisaccharide, and phytoceramide-1-H-phosphonate. The most challenging (1 → 2)-β-tetramannan domain was synthesized in one pot using the preactivation method. The phytoceramide-1-H-phosphonate was synthesized through an enantioselective A3 three-component coupling reaction. Finally, the phytoceramide-1-H-phosphonate moiety was coupled with pseudodisaccharide followed by deacetylation to produce the acceptor, which on subsequent coupling with tetramannosyl-H-phosphonate provided the fully protected PLM anchor. Final deprotection was successfully achieved by Pearlman's hydrogenation.
Tailoring chemoenzymatic oxidation: Via in situ peracids
Re, Rebecca N.,Proessdorf, Johanna C.,La Clair, James J.,Subileau, Maeva,Burkart, Michael D.
supporting information, p. 9418 - 9424 (2019/11/14)
Epoxidation chemistry often suffers from the challenging handling of peracids and thus requires in situ preparation. Here, we describe a two-phase enzymatic system that allows the effective generation of peracids and directly translate their activity to the epoxidation of olefins. We demonstrate the approach by application to lipid and olefin epoxidation as well as sulfide oxidation. These methods offer useful applications to synthetic modifications and scalable green processes.
Facile synthesis of sugar lactols via bromine-mediated oxidation of thioglycosides
Meng, Shuai,Bhetuwal, Bishwa Raj,Acharya, Padam P.,Zhu, Jianglong
, p. 109 - 126 (2019/03/26)
Synthesis of a variety of sugar lactols (hemiacetals) has been accomplished in moderate to excellent yields by using bromine-mediated oxidation of thioglycosides. It was found that acetonitrile is the optimal solvent for this oxidation reaction. This approach involving bromine as oxidant is superior to that using N-bromosuccinimide (NBS) which produces byproduct succinimide often difficult to separate from the lactol products.
Regio- and Stereoselective Synthesis of 1,2- cis-Glycosides by Anomeric O-Alkylation with Organoboron Catalysis
Izumi, Sanae,Kobayashi, Yusuke,Takemoto, Yoshiji
supporting information, p. 665 - 670 (2019/01/21)
Regio- and stereoselective synthesis of 1,2-cis-glycosides has been achieved by catalytic anomeric O-alkylation using organoboron compounds. Modulating steric and electronic factors of both catalysts and substrates enables activation of the axially oriented anomeric oxygens of glucose-derived dialkoxyborates. The mild reaction conditions allow broad functional-group tolerance. This approach can be applied to the efficient sequential synthesis of oligosaccharides.
Preparation method of tribenoside
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Paragraph 0028; 0029; 0030; 0034-0036; 0039-0040, (2018/04/02)
The invention discloses a preparation method of tribenoside. The method comprises the following steps: adding monoacetone glucose and a phase transfer catalyst to benzyl chloride, controlling the reaction temperature of a system, adding an inorganic base solution dropwise to obtain a crude product of tribenzyl monoacetone glucose, performing three-stage molecular distillation for purification toobtain high-purity tribenzyl monoacetone glucose, and adding high-purity tribenzyl monoacetone glucose to ethanol hydrochloride to prepare tribenoside. The method has the advantages of simple and efficient synthesis process, reasonable process, high synthesis efficiency and high yield; reaction operation is simple and convenient, tribenoside contains fewer impurities and is higher in purity and content, operation is convenient, and the European pharmacopoeia standards can be met directly.
Organo-zinc Promoted Diastereoselective C-Arylation of 1,2-Anhydrosugars from Arylboronic Acids
Tatina, Madhu Babu,Kusunuru, Anil Kumar,Mukherjee, Debaraj
, p. 4624 - 4627 (2015/09/28)
α-C-arylglycosides can be obtained through the addition of aryl zinc reagents to sugar epoxides. The required aryl zinc nucleophiles can be easily obtained from the corresponding boronic acids by B-Zn exchange and attack sugar 1,2 epoxides in a highly diastereoselective fashion to generate 1,2-cis-α-hexapyranosyl aryl glycosides under ligand- and base-free conditions.
A tin-free regioselective radical de-o-benzylation by an intramolecular hydrogen atom transfer on carbohydrate templates
Attouche, Angie,Urban, Dominique,Beau, Jean-Marie
, p. 9572 - 9575 (2013/09/23)
Radically selective: A remarkable 1,7-hydrogen atom transfer of a benzylic hydrogen atom to an O-silylmethylene radical initiates a regioselective de-O-benzylation of benzylated saccharides. The reaction terminates by an ionic mechanism and is general for hydroxy benzylated substrates having a variety of functional groups. Copyright
Armed-disarmed effect on the stability of cysteine thioglucosides
Nokwequ, Mbulelo G.,Nkambule, Comfort M.,Gammon, David W.
, p. 18 - 23 (2013/01/14)
Thioglucosides of cysteine show variable stability depending on the nature of the protecting groups on the glycosyl donor. Armed protecting groups (benzyl) lead to products that decompose readily while disarmed protecting groups (acetyl) lead to more stable products. Since this armed/disarmed effect of the protecting group on the stability of the thioglucosides is more pronounced for cysteine with an unprotected carboxylic group, the proposed mechanism is that decomposition is initiated by an intramolecular protonation of glycosyl sulfide and subsequent displacement of the sulfide by adventitious nucleophiles.
Stereoselective tandem epoxidation-alcoholysis/hydrolysis of glycals with molybdenum catalysts
Marin, Irene,Matheu, M. Isabel,Diaz, Yolanda,Castillon, Sergio
supporting information; experimental part, p. 3407 - 3418 (2011/02/23)
Molybdenum catalysts are efficient and selective catalysts for the tandem epoxidation/alcoholysis or epoxidation/hydrolysis of glucal and galactal derivatives. In glucal derivatives the selectivity is mainly controlled by the allylic substituent at position 3 of the glycal, obtaining in general the products derived from the initial formation of the α-epoxide (gluco) when this hydroxy group is protected, while products derived from the β-epoxide (manno) are mainly obtained when it is unprotected. In galactal derivatives the estereoselectivity is always high to give the α-epoxide (galacto) and independent of the protecting groups. Copyright
Synthesis of 1-deoxyhept-2-ulosyl-glycono-1,5-lactone utilizing α-selective O-glycosidation of 2,6-anhydro-1-deoxy-d-hept-1-enitols
Namme, Rie,Mitsugi, Takashi,Takahashi, Hideyo,Shiro, Moto,Ikegami, Shiro
, p. 9183 - 9192 (2007/10/03)
A series of 1-deoxy-heptulo-2-pyranosyl-glycono-1,5-lactones were synthesized utilizing completely α-selective O-glycosidation of heptenitols. Anomeric configuration of the products was confirmed by 3JC,H coupling measurement and X-ray crystal structural analysis. The benzyl-protected ketosyl saccharides were partly unstable, and glycosidic linkage was prone to cleave under the usual debenzylation conditions. To prevent this, we surveyed various additives for the Pd-catalyzed hydrogenation reaction and found that basic alumina was the most effective.
