Two Unexpected Effects Found with 2,3,4,6-Tetra-O-methyl-D-Gluco- and Mannopyranosyl Oxacarbenium Ions
Bibliographic record
Abstract
Analysis of two of the stable conformations (B0 and B1) of a number of differently configured glycopyranosyl oxacarbenium ions by Density Functional Theory (DFT)calculations found two unexpected phenomena. Firstly, a marked preference for O-2 to be pseudo-equatorial that most dramatically leads to the B1 conformation of D- gluco configured cations taking a 5S1 conformation. The second phenomenon is that the H-2-C-2-O-2-CH 3 torsion angle is found to prefer syn conformations over anti conformations by more than 10 kJ mol-1. Preliminary analysis of these two effects by examining the geometric consequences, the LUMO's and by Natural Bond Order (NBO) analysis are presented.
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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) | 0.002 | 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".