Synthesis of Functionalized 1-Azaspirocyclic Cyclopentanones Using Bronsted Acid or <i>N-</i>Bromosuccinimide Promoted Ring Expansions
Bibliographic record
Abstract
Azaspirocyclic ring systems are present in a variety of alkaloids. Functionalized 1-azaspirocyclopentanones (6, 7, 11, 12) can be efficiently constructed through semipinacol ring expansion reactions of 2-(1-hydroxycyclobutyl)-p-toluenesulfonylenamides (4) promoted by either a Bronsted acid ((S)-(+)-10-camphorsulfonic acid or HCl) or N-bromosuccinimide, an electrophilic bromine source. Reactions promoted by N-bromosuccinimide tend to proceed in higher yields (80-95%) and with greater diastereoselectivity (3:1-1:0) compared to those reactions promoted by a Bronsted acid. In addition, N-bromosuccinimide promoted reactions can produce a complementary stereochemical outcome compared to the reactions using Bronsted acid.
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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) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.005 | 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".