Design of a Nonreductive Method for Chemoselective Cleavage of Hydrazines in the Presence of Unsaturations: Application to a Stereoconvergent Three-Component Synthesis of (−)-Methyl Palustramate
Bibliographic record
Abstract
A chemoselective hydrazine (N-N) cleavage methodology that preserves the integrity of alkenes was developed based on a mild acid-promoted fragmentation of tetrasubstituted 1-(trimethylsilylmethyl)-1-benzylhydrazines. This strategy was applied to a concise asymmetric synthesis of (-)-methyl palustramate (4), which featured a convergent stereo- and regioselective sequential three-component aza[4+2]cycloaddition/allylboration/retro-sulfinyl-ene rearrangement between diene 1f, dienophile 2b, and propionaldehyde to afford cis-2-carboxy-6-hydroxyalkylpiperidine 25. The acid-promoted hydrazinolysis of 25 cleanly afforded key intermediate 31, and the latter led to target 4 in four steps after a series of functional group transformations.
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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 | 0.001 | 0.001 |
| 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) | 0.000 | 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".