Enantioselective access to tricyclic tetrahydropyran derivatives by a remote hydrogen bonding mediated intramolecular IEDHDA reaction
Bibliographic record
Abstract
Inverse-electron-demand-hetero-Diels-Alder reactions of alkenes with α,β-unsaturated keto compounds allow rapid access to the tetrahydropyran ring found in numerous natural products and bioactive molecules. Despite its synthetic interest, catalytic asymmetric versions of this process remain underdeveloped, especially regarding the use of non-activated alkenes reacting with α,β-unsaturated ketone or aldehyde, for which no report can be found in the literature. Herein, we describe the catalytic inverse-electron-demand-hetero-Diels-Alder reactions between neutral alkenes and an α,β-unsaturated ketones or aldehydes to produce a variety of trans-fused [5,6,8] tricyclic structures containing a central, chiral tetrahydropyran ring. This complex transformation, which is achieved using a chiral phosphoric acid, allows for the formation of four stereogenic centers in a single step with high regio-, diastereo- and enantioselectivity (up to 99% ee). Such level of stereocontrol could be achieved by a key remote double hydrogen atom bonding interaction between the linear substrate and the catalyst.
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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 | 0.003 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.003 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.001 |
| 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".