Diastereoselective spiroannulation of phenolic derivatives: Effect of steric hindrance on the diastereoselectivity.
Bibliographic record
Abstract
The objective of this study was to determine the effect, if any, that steric factors have on the oxidative spiroannulation of simple phenols bearing substituents that are increasing in size. Specifically, we wanted to determine whether or not the diastereoselectivity of the reaction would improve. To do so, the synthesis of five phenols was carried out from which four of the five spiroether targets were synthesized. Based on the [superscript]1H-NMR of these four compounds, it was found that the diastereoselectivity in these reactions did not improve it actually decreased. The fact that the diastereomeric ratios did not improve with increasing steric factors provides evidence that the spiroannulation is not affected by the size of the group attached to the 3-position. Instead, it gives supporting evidence that the stereoelectronic effect and location of the substituent has greater effect to the overall outcome of the reaction. --P.ii.
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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) | 0.001 | 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".