Intra‐ and Intermolecular Glycosylation of <scp>d</scp> ‐Idopyranosyl and 6‐Deoxy‐ <scp>d</scp> ‐ <i>ido</i> ‐heptopyranosyl Donors: Toward the Repeating Unit of <i>Campylobacter jejuni</i> HS:4c Capsular Polysaccharide
Bibliographic record
Abstract
The synthesis of disaccharide mimics of Campylobacter jejuni HS:4c capsular polysaccharide, a major pathogen associated with campylobacteriosis, is challenged by the presence of a 1,2‐ cis ‐β‐linked 6‐deoxy‐ d ‐ ido ‐heptopyranoside. Herein, the development of a synthetic route to orthogonally protected d ‐ ido ‐hexo‐ and 6‐deoxy‐ d ‐ ido ‐heptopyranosyl donors is reported bearing diverse anomeric leaving groups, which represents, to the best of knowledge, the second direct access to 6‐deoxy‐ d ‐ ido ‐heptopyranosides from ido ‐configured precursors. These donors were evaluated in intramolecular aglycon delivery (IAD) and intermolecular glycosylation protocols. While IAD enabled complete β‐stereoselectivity with hexosyl donors, it failed with the heptosyl analog. Intermolecular glycosylation provided mixtures of anomers, but the use of a 7‐ O ‐acetyl‐protected heptosyl donor allowed access to the disaccharide in good yield, with chromatographic separation of the α‐ and β‐anomers. Structural analysis revealed unexpected conformational behavior, with the α‐disaccharide adopting the 1 C 4 chair conformation. This work establishes a foundation for the synthesis of C. jejuni HS:4c disaccharides and represents a step toward well‐defined sugar‐based vaccines candidates against campylobacteriosis.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".