Notes: CL-C2 Acetyl Migration on Methylation of the Anomeric 1,3,4,6-Tetra-O-acetyl-D-glucopyranoses

Bonner, W. Hallam

doi:10.1021/jo01091a639

Cited by 66 publications

(19 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Results and Discussion The facile migrations of acyl groups in partially acylated polyhydroxylic compounds first noted by Fischer (2), have been observed under neutral, basic, and acidic conditions, and have been reported to originate at all positions except C-6 in the hexose series (3,4). As a consequence, the number of reactions that may be carried out in the partially acetylated sugars without affecting the acetylated positions is severely limited.…”

Section: Introductionmentioning

confidence: 93%

“…With the exception of the methylation of acidic hydroxyls by diazomethane, all the procedures currently used in carbohydrate chemistry for methylation involve basic conditions (5) which could lead to hydrolysis or migration of the acetyl groups (4,6). Indeed, the migration of acetyl groups during methylation has been used advantageously in some syntheses (7).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Enzymic deacylation of esterified mono- and disaccharides. 3. The location of acetylated positions in partially acetylated sugars

Fink¹,

Hay²

1969

Can. J. Chem.

View full text Add to dashboard Cite

The nitrate ester, formed by reaction with fuming nitric acid in acetic anhydride at 0 'C, was suitable to block free hydroxyl groups in partially acetylated sugars without acetyl migration. This allowed the acetylated positions in partially acetylated mono-and disaccharides to be located by the reaction sequence: nitration, deacetylation, methylation, de-nitration, disaccharide hydrolysis and methyl glycosylation (initial product identification by paper partition chromatography), acetylation, and analysis of the products by gas-liquid partition chromatography. D-Glucose, penta-0-acetyl-D-glucopyranose, and 2,3-di-0-acetyl-P-D-glucopyranose were used as test con~pounds in the evaluation of this scheme.

show abstract

Section: Introductionmentioning

confidence: 93%

Section: Introductionmentioning

confidence: 99%

Enzymic deacylation of esterified mono- and disaccharides. 3. The location of acetylated positions in partially acetylated sugars

Fink¹,

Hay²

1969

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…The facile migration of acyl groups in partially acylated sugars under mildly alkaline conditions is well known and has been the subject of numerous reports in the literature. 25,26 Apparently, migration of the anomeric acetate and anomerization occurred during the process of trichloroacetimidation as outlined in Scheme 3. Similar 1,2-Osilyl group migration 27,28 has been noticed by Schmidt and co-workers.…”

Section: Introductionmentioning

confidence: 99%

Regio- and stereoselective anomeric esterification of glucopyranose 1,2-diols and a facile preparation of 2-O-acetylated glucopyranosyl trichloroacetimidates from the corresponding 1,2-diols

Zhang

Liang

Wang

et al. 2007

Carbohydrate Research

View full text Add to dashboard Cite

Abstract-A highly regio-and stereoselective anomeric esterification of 3-O-allyl (or benzyl, or benzoyl)-4,6-O-isopropylidene-a,b-D D-glucopyranose with acetyl chloride, or allyl chloroformate, or ethyl chloroformate gave the corresponding 2-OH, 1-b-acetates or -carbonates in excellent yields. The 2-OH, 1-b-acetates were readily converted to the corresponding 2-O-acetylated glucopyranosyl trichloroacetimidates by reaction with trichloroacetonitrile via base promoted acetyl migration, while the 2-OH, 1-b-carbonates were good glycosyl acceptors for the synthesis of (1!2)-linked oligosaccharides.

show abstract

“…Acetyl group migration is an intramolecular transesterification reaction and proceeds by nucleophilic acyl substitution. A hydroxyl group adjacent to the acetyl ester serves as the attacking nucleophile, and a cyclic ortho ‐acid ester intermediate is produced (Bonner 1959). Elimination happens in both directions, so the acetyl ester either remains in its initial position on the sugar or is transferred to the attacking hydroxyl group.…”

mentioning

confidence: 99%

Feruloylated Wheat Bran Arabinoxylans: Isolation and Characterization of Acetylated and O–2‐Monosubstituted Structures

et al. 2016

View full text Add to dashboard Cite

1Arabinoxylan structures vary based on the degree and pattern of substitution of the 2 β-(1→4)-linked D-xylopyranose backbone with α-L-arabinofuranose units, acetyl groups, 3 uronic acids, and feruloylated side chains. Substitution differences affect arabinoxylans' 4 physicochemical and physiological characteristics. Wheat bran arabinoxylans were 5 hydrolyzed with GH10 and GH11 endo-1,4-β-xylanases, and feruloylated oligosaccharides 6 were isolated and purified (Amberlite XAD-2, Sephadex LH-20, and preparative RP-HPLC). 7 The pure, isolated compounds were structurally characterized via LC-ESI-MS and 1D-and 8 2D-NMR analyses. In addition to the well-known products of endo-xylanase hydrolysis 9 (xylotriose and xylobiose O-3-substituted with a 5-O-trans-feruloyl-α-arabinofuranosyl unit 10 on the middle and non-reducing xylose residue, respectively), novel structural features, 11 including O-2-monosubstitution of xylose adjacent to a xylose carrying feruloylated 12 arabinose, were observed. Additionally, a simultaneously acetylated and feruloylated 13 oligosaccharide has been isolated and tentatively characterized. Oligosaccharides esterified 14with caffeic acid were also isolated, but these were proven to result, at least in part, as 15 artefacts of the enzymatic hydrolysis.

show abstract

Notes: CL-C2 Acetyl Migration on Methylation of the Anomeric 1,3,4,6-Tetra-O-acetyl-D-glucopyranoses

Cited by 66 publications

References 2 publications

Enzymic deacylation of esterified mono- and disaccharides. 3. The location of acetylated positions in partially acetylated sugars

Enzymic deacylation of esterified mono- and disaccharides. 3. The location of acetylated positions in partially acetylated sugars

Regio- and stereoselective anomeric esterification of glucopyranose 1,2-diols and a facile preparation of 2-O-acetylated glucopyranosyl trichloroacetimidates from the corresponding 1,2-diols

Feruloylated Wheat Bran Arabinoxylans: Isolation and Characterization of Acetylated and O–2‐Monosubstituted Structures

Contact Info

Product

Resources

About