Synthesis of trichiliasterones A and B 16-Ketosteroids isolated from <i>Trichilia hirta</i> and <i>Trichilia americana</i>
Bibliographic record
Abstract
The syntheses of trichiliasterone A (3β-hydroxypregnan-2,16-dione) and trichiliasterone B (2-hydroxyandrost-1,4-diene-3,16-dione) have been carried out starting from isoandrosterone and testosterone acetate, respectively. In each synthesis the functionality in the D ring was installed prior to working on ring A. In the case of trichiliasterone A, the D ring chemistry involved a Wittig reaction to generate the 17-methylene group, followed by SeO 2 oxidation to give an α,β-unsaturated ketone. Reaction with lithium dimethyl cuprate gave the required 17-ethyl-16-keto functionality. A 2,3-epoxy enol acetate served as the key intermediate for the generation of the 2-keto-3-hydroxy functions in ring A. The transposition of the keto function from C-16 to C-17 in the synthesis of trichiliasterone B was accomplished via oxymercurationdemercuration of the Δ 1617 double bond followed by oxidation. The hydroxyl group at C-2 and the additional ring A unsaturation were introduced by lead tetra-acetate treatment of the 3-keto-4-enone function and subsequent air oxidation.Key words: 16-ketosteroids, plant steroids, Trichilia hirta, trichiliasterones.
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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".