Oxa‐Michael–Michael Reaction of MBH Alcohol and 2‐Arylidene‐1,3‐indanedione: Regioselective Formal [4+2] Cycloaddition towards Tetrahydrospiropyran Scaffolds
Bibliographic record
Abstract
A regioselective formal [4+2] cycloaddition reaction of nitrostyrene derived MBH alcohol and 2‐arylidene‐1,3‐indanedione resulted in functionalized tetrahydrospiropyran derivatives with excellent chemical yields (up to 93 %). The reaction tolerated various electron rich and electron deficient substituents on the aryl group of 2‐arylidene‐1,3‐indanedione as well as MBH alcohol. The utility of MBH alcohol as an ambident substrate, which is performing the dual role of nucleophile and electrophile with 2‐arylidene‐1,3‐indanediones was successfully demonstrated for 20 derivatives. A single isomer was obtained exclusively in all the products via cascade process which followed an oxa‐Michael–Michael addition sequence using cesium carbonate as base. Control experiments were carried out to understand the mechanistic details of the reaction. These experiments prove that the reaction undergoes a stepwise pathway rather than a concerted mechanism.
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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) | 0.001 | 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 | 0.001 |
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".