Ring-opening of hindered cyclic epoxides with potassium carboxylates in the presence of conjugate acids
Bibliographic record
Abstract
During attempts to ring-open a highly hindered epoxide, traditional methods were found to be ineffective. An alternative strategy for opening epoxides was implemented that employed a potassium carboxylate in the presence of its conjugate acid in a solvent mixture containing polar and potassium-sequestering components. A systematic analysis of the components of the reaction mixture indicated that the addition of the conjugate acid was the most important feature for providing good conversion. This reaction appears to be general for most classes of carboxylic acids including cinnamic, aromatic, and highly hindered carboxylic acids (30%–79% yield) and only fails with weak carboxylate nucleophiles. Three highly substituted and hindered cyclohexene oxide derivatives were examined for reactivity and the reaction conditions appear to tolerate a variety of functional groups to provide the ring-opened species. This pH-moderate system proved useful for hindered cyclic epoxides when all other techniques failed and should prove general to a wide spectrum of epoxide and carboxylic acid partners in those cases where the use of a strong Lewis or protic acid catalyst, or a strong basic nucleophile, is inappropriate.
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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) | 0.000 | 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 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".