Synthèse totale de la (2S,3R,4S)-4-hydroxyisoleucine et de ses analogues : Mise au point d'une déprotection de para-méthoxyamines par voie électrochimique
Bibliographic record
Abstract
Nowadays, the medicinal research takes profit of organic transformations to develop novel synthetic methodologies to afford for example bioactive molecules present in plants. In this manuscript, various facets in organic chemistry have been investigated. The main one was focused on the total synthesis of (2S,3R,4S)-4-Hydroxyisoleucine, a natural product extracted from fenugreek seeds. It is a small amino acid bearing three contiguous stereogenic centers and having some interesting anti-diabetic properties. Two approaches have been designed and successfully validated. The first one is a racemic approach and afforded the (2S,3R,4S)-4-Hydroxyisoleucine and its isomers. It involves a catalytic diastereoselective hydrogenation reaction of an -iminoester precursor. The second strategy aims at developing an industrial scale synthesis of the optically pure natural compound. It is based on the catalytic asymmetric Mannich-Type condensation reaction and the diastereoselective reduction of an N-Protected--keto--aminoester to afford in a four-step synthesis the (2S,3R,4S)-4-Hydroxyisoleucine with a good overall yield and the use of available and cheap starting materials. This synthetic approach also allowed the synthesis of 4-Hydroxyisoleucine’s analogues and their potential anti-diabetic properties are at the moment evaluated in Canada. Besides this project, I studied a regiospecific synthesis of isoxazoles starting from ,-diketonic esters and I examined the use of Rhodium and Ruthenium organometallic complexes in catalytic asymmetric regiospecific hydrogenation of ,-disubstituted-(acetamido)acrylates. I have also worked on the selective deprotection of the para-methoxyphenyl group through anodic oxidation. This electrochemical route can afford primary amine derivatives and constitutes an alternative to the use of classical and environmental unfriendly oxidants such as CAN.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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) | 0.002 | 0.001 |
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 source (direct Gemma or distilled Codex), 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".