An expeditious synthesis of (±)-decahydro-5<i>H</i>-dipyrrolo [1,2-<i>a</i>:1',2'-<i>c</i>]pyrimidine-5-carbonitrile: a formal synthesis of (±)-tetraponerines-1, -2, -5, and -6
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Bibliographic record
Abstract
A short and practical synthesis of (±)-decahydro-5H-dipyrrolo[1,2-a:1',2'-c]pyrimidine-5-carbonitrile (17), a pivotal intermediate in the synthesis of (±)-tetraponerines-1 (5), -2 (6), -5 (7), and -6 (8), in three steps and 24% overall yield, from simple and inexpensive starting materials, is reported. The key step of our synthesis is a one pot stereoselective multistep process, whereupon two molecules of Δ 1 -pyrroline (9) react with diethyl malonate (10) to afford the tricyclic lactam ester 13, possessing the tetraponerine skeleton. Hydrolysis of the carboethoxy group of 13 followed by decarboxylation yields lactam 15, which is converted into α-aminonitrile 17. Our fruitless efforts to transform lactam 15 into the tetraponerines through reductive alkylation are also discussed.Key words: alkaloids, tetraponerines, stereoselective synthesis, Robinson-Schöpf reaction, lactams, ants.
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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 | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 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