Synthesis of Bacterial Cell Envelope Components

Ishiwata, Akihiro; Ito, Yukishige

doi:10.1002/9781119006435.ch14

Cited by 6 publications

(8 citation statements)

References 299 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The problem arises because of the location of typical glycosylation reactions at the interface between S N 1 and S N 2 reactions where minor changes in structure and conditions cause major shifts in mechanism, 17–19 is compounded by the iterative nature of oligosaccharide synthesis, and is particularly significant in the preparation of the microbial glycans with their great structural diversity and complexity. 20–24 Indeed, notwithstanding the several spectacular syntheses published in recent years, 25–35 the surface of the microbial glycan problem has barely been scratched leaving many challenges for the ingenuity of the organic chemist.…”

Section: Introductionmentioning

confidence: 99%

“…In spite of the many advances in chemical and enzymatic glycosidation, whether automated or classical, in recent years, − the stereocontrolled synthesis of many classes of glycosidic bond continues to be a significant challenge that retards the preparation of saccharides, oligosaccharides, and their conjugates for biomedical research. The problem arises because of the location of typical glycosylation reactions at the interface between S N 1 and S N 2 reactions where minor changes in structure and conditions cause major shifts in mechanism, − is compounded by the iterative nature of oligosaccharide synthesis, and is particularly significant in the preparation of the microbial glycans with their great structural diversity and complexity. − Indeed, notwithstanding the several spectacular syntheses published in recent years, − the surface of the microbial glycan problem has barely been scratched leaving many challenges for the ingenuity of the organic chemist.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Synthesis and Stereocontrolled Equatorially Selective Glycosylation Reactions of a Pseudaminic Acid Donor: Importance of the Side-Chain Conformation and Regioselective Reduction of Azide Protecting Groups

Dhakal

Crich

2018

J. Am. Chem. Soc.

View full text Add to dashboard Cite

Pseudaminic acid is an amino deoxy sialic acid whose glycosides are essential components of many pathogenic Gram-negative bacterial cell walls including those from Pseudomonas aeruginosa, Vibrio cholerae, Campylobacter jejuni, Campylobacter coli, Vibrio vulnificus, and Pseudoalteromonas distincta. The study of pseudaminic acid glycosides is however hampered by poor availability from nature, the paucity of good synthetic methods, and limited to no understanding of the factors controlling stereoselectivity. Conformational analysis of the side chains of various stereoisomeric sialic acids suggested that the side chain of pseudaminic acid would take up the most electron-withdrawing trans,gauche-conformation, as opposed to the gauche,gauche conformation of N-acetyl neuraminic acid and the gauche,trans-conformtion of 7-epi N-acetyl neuraminic acid, leading to the prediction of high equatorial selectivity. This prediction is borne out by the synthesis of a suitably protected pseudaminic acid donor from N-acetyl neuraminic acid in 20 steps and 5% overall yield, and by the exquisite equatorial selectivity it displays in coupling reactions with typical glycosyl acceptors. The selectivity of the glycosylation reactions is further buttressed by the development and implementation of conditions for the regioselective release of the two amines from the corresponding azides, such as required for the preparation of the lipopolysaccharides. These findings open the way to the synthesis and study of pseudaminic acid-based bacterial lipopolysaccharides and, importantly in the broader context of glycosylation reactions in general, underline the significant role played by side chain conformation in the control of reactivity and selectivity.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Synthesis and Stereocontrolled Equatorially Selective Glycosylation Reactions of a Pseudaminic Acid Donor: Importance of the Side-Chain Conformation and Regioselective Reduction of Azide Protecting Groups

Dhakal

Crich

2018

J. Am. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…323 Initially investigated for the synthesis of β -mannosides, α -glucosides, and β -arabinofuranosides, 323 this approach was extended to the synthesis of β -rhamnosides 324 and other challenging targets. 315,325–331…”

Section: Traditional Manual Synthesis Of Oligosaccharidesmentioning

confidence: 99%

“…The treatment of a mixture of donor 9 and acceptor 10 with 2,3-dichloro-5,6-dicyano- p -benzoquinone (DDQ) produces a mixed acetal that can be directly glycosidated in the presence of MeOTf and 2,6-di- tert -butyl-4-methylpyridine (DTBMP) followed by acetylation to give disaccharide 11 in an excellent yield of 90% and complete β-selectivity . Initially investigated for the synthesis of β-mannosides, α-glucosides, and β-arabinofuranosides, this approach was extended to the synthesis of β-rhamnosides and other challenging targets. ,− …”

Section: Traditional Manual Synthesis Of Oligosaccharidesmentioning

confidence: 99%

Automated Chemical Oligosaccharide Synthesis: Novel Approach to Traditional Challenges

et al. 2018

View full text Add to dashboard Cite

Advances in carbohydrate chemistry have certainly made common oligosaccharides much more accessible. However, many current methods still rely heavily upon specialized knowledge of carbohydrate chemistry. The application of automated technologies to chemical and life science applications such as genomics and proteomics represents a vibrant field. These automated technologies also present opportunities for their application to organic synthesis, including that of the synthesis of oligosaccharides. However, application of automated methods to the synthesis of carbohydrates is an underdeveloped area as compared to other classes of biomolecules. The overarching goal of this review article is to present the advances that have been made at the interface of carbohydrate chemistry and automated technology.

show abstract

“…Without further purification, the latter mixture can be glycosylated in the presence of MeOTf and DTBMP followed by acetylation to give disaccharide 77 in an excellent yield of 90% and complete β-selectivity [ 100 ]. Initially investigated for the synthesis of β-mannosides, α-glucosides, and β-arabinofuranosides [ 100 ], this approach was extended to the synthesis of β-rhamnosides [ 101 ] and many other challenging linkages and targets [ 41 , 102 – 108 ].…”

Section: Reviewmentioning

confidence: 99%

Intramolecular glycosylation

Jia¹,

Demchenko²

2017

Beilstein J. Org. Chem.

View full text Add to dashboard Cite

Carbohydrate oligomers remain challenging targets for chemists due to the requirement for elaborate protecting and leaving group manipulations, functionalization, tedious purification, and sophisticated characterization. Achieving high stereocontrol in glycosylation reactions is arguably the major hurdle that chemists experience. This review article overviews methods for intramolecular glycosylation reactions wherein the facial stereoselectivity is achieved by tethering of the glycosyl donor and acceptor counterparts.

show abstract

Synthesis of Bacterial Cell Envelope Components

Cited by 6 publications

References 299 publications

Synthesis and Stereocontrolled Equatorially Selective Glycosylation Reactions of a Pseudaminic Acid Donor: Importance of the Side-Chain Conformation and Regioselective Reduction of Azide Protecting Groups

Synthesis and Stereocontrolled Equatorially Selective Glycosylation Reactions of a Pseudaminic Acid Donor: Importance of the Side-Chain Conformation and Regioselective Reduction of Azide Protecting Groups

Automated Chemical Oligosaccharide Synthesis: Novel Approach to Traditional Challenges

Intramolecular glycosylation

Contact Info

Product

Resources

About