Nonracemic Bicyclic Lactam Lactones via Regio- and <i>cis</i>-Diastereocontrolled C−H Insertion. Asymmetric Synthesis of (8<i>S</i>,8a<i>S</i>)-Octahydroindolizidin-8-ol and (1<i>S</i>,8a<i>S</i>)-Octahydroindolizidin-1-ol
Why this work is in the frame
A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.
Bibliographic record
Abstract
The Rh(2)(MPPIM)(4)-catalyzed intramolecular C-H insertion reaction of (S)- and (R)-1-benzyl-5-(alpha-diazoacetoxy)piperidin-2-one and (S)-1-benzyl-4-(alpha-diazoacetoxy)pyrrolidin-2-one proceeds with high regioselectivity and cis-diastereoselectivity to give good yields of chiral nonracemic bicyclic lactam lactones (BLLs). For (S)- and (R)-1-benzyl-5-(alpha-diazoacetoxy)piperidin-2-one, the regioselectivity of the C-H insertion is catalyst-dependent; for example, (S)-1-benzyl-5-(alpha-diazoacetoxy)piperidin-2-one undergoes C-H insertion at C-6 preferentially when Rh(2)(5S-MPPIM)(4) is used, but with Rh(2)(5R-MPPIM)(4), C-H insertion occurs preferentially at C-4. This effect is not observed in the reaction of (S)-1-benzyl-4-(alpha-diazoacetoxy)pyrrolidin-2-one. The utility of the BLLs as chiral building blocks in alkaloid synthesis is exemplified by the synthesis of (8S,8aS)-octahydroindolizidin-8-ol and (1S,8aS)-octahydroindolizidin-1-ol.
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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) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.001 | 0.002 |
| 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 it