Methodology for natural product synthesis : sordarin, himandrine and lepadiformine
Bibliographic record
Abstract
Fungal infection, of small concern in healthy individuals, can become problematic in immunosuppressed patients with illnesses such as AIDS, and the search for substances that exert antifungal action by new mechanisms continues. A noteworthy group of potent antimycotic natural products known as the sordarins meet this criterion. In order to investigate the effect of various functional and skeletal changes to sordarin on anti-pathogenic activity, we have devised practical, expeditious, and efficient routes to analogs of the natural product. The bioactivity of the new compounds against various pathogenic fungi was evaluated. This research constitutes the first half of my doctoral dissertation. The second half of my work centers on the development of a practical method for the oxidative amidation of phenols. This reaction achieves the conversion of phenols into spirocyclic (sulfon)amido-dienones. The new methodology forms the centerpiece of envisioned syntheses of (±)-himandrine and (-)-lepadiformines. Himandrine, isolated from the bark of Galbulimima belgraveana, displays anticholinergic activity and is thus of potential interest for the treatment of a number of human ailments. Our himandrine skeleton synthesis centered on a tandem oxidative amidation and Diels-Alder reaction, using three different approaches. The alkaloid (-)-lepadiformines displays potency as a potassium channel blocker. Our synthetic study towards this substance utilizes the oxidative cyclization of a phenolic sulfonamide as the key step. The resulting dienone is then desymmetrized through a stereoselective Michael addition leading to an enantiopure tricyclic intermediate, to which hydrocarbon side chain was appended in high yield. Further elaboration will lead to the natural product.
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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 | 0.000 |
| 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".