A conceptually novel strategy has been developed for the synthesis of N-(β-glycosyl)asparagine precursors in good yield by the alkylation of ethyl nitroacetate using six per-O-acetylated N-(β-glycosyl)iodoacetamides derived from mono- and disaccharides. The use of a chiral organocatalyst, N-(9-anthracenylmethyl)cinchoninium chloride (10 mol %), resulted in diastereoselective alkylation up to 64% de. Single crystal structure analysis of the purified major diastereomer of the Glc derivative revealed an absolute configuration of S at the α-carbon of the monosubstituted ethyl nitroacetate which is a precursor of the l-asparagine conjugate. © 2010 Elsevier Ltd. All rights reserved.

Katuri J V Paul

Laxminarayan Sahoo

Duraikkannu Loganathan

acetamide derivative

acetic acid derivative

anthracene derivative

ASPARAGINE DERIVATIVE

ETHYLNITROACETIC ACID

N (9 ANTHRACENYLMETHYL)CINCHONINIUM CHLORIDE

N (BETA GLYCOSYL)ASPARAGINE DERIVATIVE

N (BETA GLYCOSYL)IODOACETAMIDE DERIVATIVE

unclassified drug

Alkylation

article

chirality

Crystal Structure

stereochemistry

structure analysis

synthesis

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Tetrahedron Letters

In recent years, 1,4-triazole rings are being widely used for the synthesis of carbohydrate derived biomimetics, due to their easy synthesis and wide range of functional group compatibility. These triazole rings lead to synthetic molecules with improved enzymatic stability, bioavailability, and structural diversity. In this present work, a benzoyl group has been introduced at the C-5 position of the triazole ring present in the synthetic glycoconjugates providing further structural diversity to the molecule. 5-Benzoyl 1,4-triazole ring containing glycoconjugates were synthesized using Cu(I) catalyzed [3 + 2] cycloaddition reaction of per-O-acetylated glycopyranosyl azide and phenyl acetylene followed by in situ electrophilic addition of benzoyl group to the Cu(I) coordinated triazole intermediate. The X-ray crystal structure of one of the 5-benzoyl 1,4-triazole linked glycoconjugate derived from D-xylose {1-N-(2,3,4-tri-O-acetyl-β-D-xylopyranosyl)-4-phenyl-5-benzoyl-1,2,3-triazole} showed unique pattern of intermolecular C–H…O interactions arranging the molecules in an anti-parallel orientation. The structure and morphology of the compounds were further explored using computational calculation and scanning electron microscopic (SEM) study which firmly established the uniqueness of 5-benzoyl 1,4-triazole linked glycoconjugates compared to that of 5-H 1,4-triazole linked derivative. © 2018 Elsevier Ltd

Carbohydrate Research

5-Benzoyl triazole as new structural dimension in glycoconjugates

A method for the chemoselective reduction of glycopyranosyl azides using SnCl4 and tin metal as the reducing agent followed by in situ chloroacetylation of the synthesized glycopyranosyl amine was developed. This reaction is applicable to diversely functionalized glycopyranosyl azides for the synthesis of glycopyranosyl chloroacetamides. © 2013 Elsevier Ltd. All rights reserved.

SnCl4/Sn catalyzed chemoselective reduction of glycopyranosyl azides for the synthesis of diversely functionalized glycopyranosyl chloroacetamides

The β-glucosyl linkage to the guanidine group of arginine (Arg) is found in amylogenin, a glycoprotein from sweet corn. Such a linkage is formed by a rare N-glycosylation of proteins. Synthesis of analogs of the unusual N-glycosidic linkage (GlcβArg) with an acetamido or triazole spacer between the glycosyl residue and the guanidine moiety was accomplished by the reaction of fully acetylated sugar unit containing a free amino group with bis-Boc-thiourea. Synthesis of N-glucosylarginine with an amido linker was also achieved during the present study. This methodology was also extended to the synthesis of cationic glucolipid. © 2013 Springer Science+Business Media New York.

Glycoconjugate Journal

Synthesis of guanidino sugar conjugates as GlcβArg analogs

Crystal structures of 1-N-(β-D-glucopyranosyl)chloroacetamide (1), an inhibitor of glycogen phosphorylase, and the corresponding galactopyranosyl amide (2) have been determined. Both crystals belong to P212 121 space group with 1 having the unit cell dimensions of a = 7.939(3), b = 9.547(3) and c = 14.157(2) Å, while those of 2 are, a = 7.636(10), b = 9.004(8) and c = 14.807(5) Å. The sugar ring takes a 4C1 conformation and the amide linkage exists in Z-anti conformation in both crystals. The torsion angle O5-C1-N1-C1′ is -93.9(5) for 1 and -111.5(3)° for 2. The conformational preference of Cl and N1 in 1 and 2 is found to be between anti and gauche. The molecular assembly in both 1 and 2 is stabilized by a finite chain of hydrogen bonds starting from N1H and ending at O1′, whereas a ten membered hydrogen-bonded ring involving O4H and O5 is observed in 1.

Journal of Carbohydrate Chemistry

Crystal Structures of β-1-N-Chloroacetamido Derivatives of D-Glucose and D-Galactose

Chemical Reviews

Recent Development and Application of Chiral Phase-Transfer Catalysts

Journal of the American Chemical Society

Efficient Stereoselective Synthesis of γ-N-Glycosyl Asparagines by N-Glycosylation of Primary Amide Groups

Glycobiology

Protein glycosylation: nature, distribution, enzymatic formation, and disease implications of glycopeptide bonds

Synthesis

A Simple Method for the Synthesis of Nβ-Glycosylated-Asparagine and -Glutamine Derivatives

A novel strategy toward the synthesis of N-(β-glycosyl)asparagines based on the alkylation of ethyl nitroacetate using N-(β-glycosyl) iodoacetamides

Journal	Tetrahedron Letters
ISSN	00404039
Open Access	No