4137-35-3Relevant academic research and scientific papers
Triethylamine-methanol mediated selective removal of oxophenylacetyl ester in saccharides
Rasool, Javeed Ur,Kumar, Atul,Ali, Asif,Ahmed, Qazi Naveed
, p. 338 - 347 (2021/01/29)
A highly selective, mild, and efficient method for the cleavage of oxophenylacetyl ester protected saccharides was developed using triethylamine in methanol at room temperature. The reagent proved successful against different labile groups like acetal, ketal, and PMB and also generated good yields of the desired saccharides bearing lipid esters. Further, we also observed DBU in methanol as an alternative reagent for the deprotection of acetyl, benzoyl, and oxophenylacetyl ester groups. This journal is
Noncatalytic selective 6-O-acetylation of methyl 2,3-di-O-benzoyl-α-d-glucopyranoside with acetic acid and acetic anhydride
Gening, M. L.,Nifantiev, N. E.,Tsvetkov, Y. E.
, p. 2228 - 2230 (2020/12/07)
Noncatalytic acetylation of methyl 2,3-di-O-benzoyl-α-d-glucopyranoside with acetic acid or acetic anhydride proceeds regioselectively at the primary hydroxyl group and affords methyl 6-O-acetyl-2,3-di-O-benzoyl-α-d-glucopyranoside in good yield. The possibility of 6-O-acetylation should be taken into account when removing a 4,6-O-benzylidene protecting group with aqueous acetic acid at elevated temperature.
Mapping the Relationship between Glycosyl Acceptor Reactivity and Glycosylation Stereoselectivity
van der Vorm, Stefan,van Hengst, Jacob M. A.,Bakker, Marloes,Overkleeft, Herman S.,van der Marel, Gijsbert A.,Codée, Jeroen D. C.
supporting information, p. 8240 - 8244 (2018/05/03)
The reactivity of both coupling partners—the glycosyl donor and acceptor—is decisive for the outcome of a glycosylation reaction, in terms of both yield and stereoselectivity. Where the reactivity of glycosyl donors is well understood and can be controlled through manipulation of the functional/protecting-group pattern, the reactivity of glycosyl acceptor alcohols is poorly understood. We here present an operationally simple system to gauge glycosyl acceptor reactivity, which employs two conformationally locked donors with stereoselectivity that critically depends on the reactivity of the nucleophile. A wide array of acceptors was screened and their structure–reactivity/stereoselectivity relationships established. By systematically varying the protecting groups, the reactivity of glycosyl acceptors can be adjusted to attain stereoselective cis-glucosylations.
Boronic esters as protective groups in carbohydrate chemistry: processes for acylation, silylation and alkylation of glycoside-derived boronates
Mancini, Ross S.,Lee, Jessica B.,Taylor, Mark S.
, p. 132 - 143 (2016/12/27)
Procedures for selective installation of acyl, silyl ether and para-methoxybenzyl (PMB) ether groups to glycoside substrates have been developed, employing phenylboronic esters as protected intermediates. The sequence of boronic ester formation, functiona
Highly Regioselective Monoacylation of Unprotected Glucopyranoside Using Transient Directing-Protecting Groups
Rocheleau, Sylvain,Pottel, Joshua,Huski?, Igor,Moitessier, Nicolas
, p. 646 - 656 (2017/02/05)
The regioselective functionalization of monosaccharides is notoriously achieved using metal catalysis, lengthy synthetic strategies requiring protection/deprotection, various enzymes, or other methods that target cis-diols (and thus cannot be used with glucopyranose derivatives), In this paper, we report a new method using selected boronic acids as temporary protecting groups, and describe its application to the regioselective functionalization of methyl α-d-glucopyranoside, the most difficult monosaccharide to functionalize regioselectively. Generally, reactions of glucopyranosides may lead to a plethora of mono- and polyfunctionalized derivatives, yet our method gave the 3-O-acetylated, 2-O-benzoylated, and 2-O-pivaloylated derivatives of methyl α-d-glucopyranoside as major products. We focused on the use of recyclable and green temporary protecting groups (in a one-pot reaction) and on the modulation of the intramolecular hydrogen-bonding network using selected arylboronic acids. A complete scalable procedure leading to a single regioisomer from unprotected methyl α-d-glucopyranoside is presented.
Regiospecific anomerisation of acylated glycosyl azides and benzoylated disaccharides by using TiCl4
Farrell, Mark,Zhou, Jian,Murphy, Paul V.
, p. 14836 - 14851 (2013/11/06)
Chelation induced anomerisation is promoted when Lewis acids, such as TiCl4 or SnCl4, coordinate to the pyranose ring oxygen atom and another site, giving rise to endocyclic cleavage and isomerisation to the more stable anomer. In this research regiospecific site-directed anomerisation is demonstrated. TiCl4 (2.5equiv) was employed to induce anomerisation of 15 glycosyl azide and disaccharide substrates of low reactivity, and high yields (>75 %) and stereoselectivies (α/β>9:1) were achieved. The examples included glucopyranuronate, galactopyranuronate and mannopyranuronate as well as N-acetylated glucopyranuronate and galactopyranuronate derivatives. A disaccharide with the α1→4 linkage found in polygalacturonan was included. The use of benzoylated saccharides was found to be important in disaccharide anomerisation as attempts to isomerise related acetyl protected and 2,3-carbonate protected derivatives were not successful. Copyright
Cleavage of 4,6- O -benzylidene acetal using sodium hydrogen sulfate monohydrate
Michigami, Kyosuke,Terauchi, Manami,Hayashi, Masahiko
, p. 1519 - 1523 (2013/06/27)
The use of protecting groups is an important protocol in carbohydrate synthesis. Among protecting groups, benzylidene acetals are generally more stable than other acetals; therefore, strong conditions are often required for deprotection. We report the deprotection of 4,6-O-benzylidene derivatives using sodium hydrogen sulfate monohydrate under mild conditions. Georg Thieme Verlag Stuttgart New York.
Enantioselective alkylation of aldehydes using dialkylzincs catalyzed by simple chiral diols derived from naturally occurring monosaccharides
Michigami, Kyosuke,Hayashi, Masahiko
supporting information, p. 4221 - 4225 (2013/06/27)
Enantioselective alkylation of aldehydes was achieved in up to 84% ee using dialkylzincs catalyzed by simple diols derived from naturally occurring monosaccharides.
Removal of benzylidene acetal and benzyl ether in carbohydrate derivatives using triethylsilane and Pd/C
Santra, Abhishek,Ghosh, Tamashree,Misra, Anup Kumar
, p. 74 - 78 (2013/03/28)
Clean deprotection of carbohydrate derivatives containing benzylidene acetals and benzyl ethers was achieved under catalytic transfer hydrogenation conditions by using a combination of triethylsilane and 10% Pd/C in CH 3OH at room temperature. A variety of carbohydrate diol derivatives were prepared from their benzylidene derivatives in excellent yield.
Synthesis and structure elucidation of benzoylated deoxyfluoropyranosides
Esmurziev, Aslan M.,Simic, Nebojsa,Hoff, Bard Helge,Sundby, Eirik
scheme or table, p. 348 - 367 (2011/09/30)
Benzoylated deoxyfluoropyranosides have been synthesized, starting with protected, unprotected, or fluorinated precursors. Fluorination of eight derivatives was compared using DAST and Deoxo-Fluor as reagents. Deoxo-Fluor was found to be especially useful
