Total Synthesis of (6<i>R</i>,10<i>R</i>,13<i>R</i>,14<i>R</i>,16<i>R</i>,17<i>R</i>,19<i>S</i>,20<i>R</i>,21<i>R</i>,24<i>S</i>, 25<i>S</i>,28<i>S</i>,30<i>S</i>,32<i>R</i>,33<i>R</i>,34<i>R</i>,36<i>S</i>,37<i>S</i>,39<i>R</i>)‐Azaspiracid‐3 Reveals Non‐Identity with the Natural Product
Bibliographic record
Abstract
A convergent and stereoselective total synthesis of the previously assigned structure of azaspiracid-3 has been achieved by a late-stage Nozaki-Hiyama-Kishi coupling to form the C21-C22 bond with the C20 configuration unambiguously established from l-(+)-tartaric acid. Postcoupling steps involved oxidation to an ynone, modified Stryker reduction of the alkyne, global deprotection, and oxidation of the resulting C1 primary alcohol to the carboxylic acid. The synthetic product matched naturally occurring azaspiracid-3 by mass spectrometry, but differed both chromatographically and spectroscopically.
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 | 0.009 | 0.005 |
| Meta-epidemiology (narrow) | 0.006 | 0.005 |
| Meta-epidemiology (broad) | 0.006 | 0.004 |
| Bibliometrics | 0.001 | 0.004 |
| Science and technology studies | 0.008 | 0.009 |
| Scholarly communication | 0.004 | 0.012 |
| Open science | 0.015 | 0.008 |
| Research integrity | 0.002 | 0.006 |
| Insufficient payload (model declined to judge) | 0.019 | 0.003 |
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; both teacher heads agree on what is shown here.
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".