Stereochemistry of Cuprate-Mediated Conjugate Additions of a 17-Iodoandrost-16-ene to E- and Z-6-Methylhept-2-en-4-one
Bibliographic record
Abstract
(3 S ,15 R )-15-(Benzyloxy)-3-[( tert -butyldimethylsilyl)oxy]-17-iodoandrosta-5,16-diene ( 3 ) was prepared from the corresponding 17-hydrazone 9 with iodine in the presence of tetramethylguanidine. The vinyl iodide 3 was converted into the corresponding organocuprate and conjugate additions of the latter were performed with both ( E )- and ( Z )-6-methylhept-2-en-4-one ( 4a and 4b , respectively). In each case, the resulting adduct 5a was obtained exclusively with the unnatural 20 S configuration. (3 S ,15 R )-15-(Benzyloxy)-3-[( tert -butyldimethylsilyl)oxy]androsta-5,16-diene ( 13 ) and the corresponding 17,17' homocoupling product 14 were obtained as byproducts. When the addition to the E -enone was repeated in the presence of chloro(trimethyl)silane, the yield of the conjugate addition product improved, but the stereochemistry at C-20 remained the same.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.003 |
| 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 | 0.001 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.002 | 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".