Polycyclic oxonium ylides — Use of cyclic acetals as convenient scaffolds in the construction of fused bicyclic compounds containing a medium ring
Bibliographic record
Abstract
Cyclic mixed acetals with pendant diazoketone side chains undergo efficient rearrangement to ether-bridged cyclooctanoid and cycloheptanoid systems upon treatment with Cu(hfacac) 2 . Stevens [1,2]-shift of an oxonium ylide furnishes the major product, in some cases accompanied by minor amounts of a product resulting from [1,2]-shift of a sulfonium ylide. These results demonstrate that hetero-substituted carbons are suitable migrating groups for the Stevens [1,2]-shift of oxonium ylides. In cases employing a mixed thioacetal, the resulting sulfide served as a trigger for cleavage of the bridging ether through one of two complementary strategies. In the hydrazulene series, the desired bicyclo[5.3.0]heptene was accompanied by the product of novel transannular S N 2′ attack on the resulting allylic ketal.Key words: [1,2]-shift, diazo, medium-sized ring, oxonium ylide, ring expansion.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 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) | 0.000 | 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 teacher head, 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".