Vedrenne, Emeline (2006) Towards the total synthesis of Paulitin - New insights into metathesis reactions. PhD thesis DCSO, ENSTA / UCP - Laboratoire de Chime et Procédés, EP/X p.221.
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Alternative Locations: http://www.imprimerie.polytechnique.fr/Theses/Files/Vedrenne.pdf
Abstract
THE AIM OF THIS WORK WAS INITIALLY THE TOTAL SYNTHESIS OF PAULITINE. THE RESULTS OBTAINED LEAD US TO STUDY THE ENYNE-METATHESIS MECHANISM IN MORE DETAIL, IN ORDER TO OBTAIN THE A-B BICYCLE OF THE TARGET MOLECULE. IT WAS THEN HIGHLIGHTED THAT, FOR ENYNES WITH A TERMINAL ALKYNE AND AN OXYGEN ATOM AT THE PROPARGYLIC POSITION, THE RUTHENIUM CARBENE FIRST !
REACTS WITH THE ALKYNE. STERIC HINDRANCE AT THE PROPARGYLIC PO!
SITION S
EEMS TO INFLUENCE STRONGLY THE YIELD OF THE METATHESIS: CYCLIZATION IS MUCH EFFICIENT WHEN IT DECREASED. A DESMETHYL PRECURSOR OF THE TARGET BICYCLE WAS THEN OBTAINED IN SEVEN PERCENTS OVER EIGHT STEPS. ASYMMETRIC SYNTHESIS OF THE BICYCLE AS WELL AS FORMATION OF ALPHA-METHYLENE-GAMMA-BUTYROLACTONES WERE THEN STUDIED.PARALLEL TO THIS WORK, A NEW METHODOLOGY WAS DEVELOPED FOR THE METATHESIS OF ALLYLIC AMINO COMPOUNDS, WHICH ARE GENERALLY POOR METATHESIS-PARTNERS. THE USE OF BORON-BASED LEWIS ACIDS, ALLOWED TO CLEANLY OBTAIN COUPLING PRODUCTS. THIS NEW METHOD GAVE ACCESS TO A WIDE RANGE OF FUNCTIONALIZED OLEFINS, IN GOOD YIELDS, WHEN REACTIONS WERE LED IN REFLUXING TOLUENE FOR TWELVE HOURS, USING FIVE PERCENTS OF HOVEYDA-BLECHERT CATALYST AND ONLY ONE EQUIVALENT OF METATHESIS-PARTNER.
| Item Type: | PhD Thesis (PhD) |
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| Thesis Supervisor: | Laurence, Grimaud |
| Date: | July 2006 |
| Board of examiners: | Cossy, Janine and Kouklovsky, Cyrille and Piva, Olivier and El Kaïm, Laurent |
| Ecole Doctorale: | ED 447 ECOLE DOCTORALE DE L'ECOLE POLYTECHNIQUE |
| Discipline: | DCSO |
| Collection (Fonds): | EP/X ENSTA |
| Institution: | EP/X |
| Department: | ENSTA / UCP - Laboratoire de Chime et Procédés |
| Subjects: | 6. Chemistry, Physical Chemistry and Chemical Engineering |
| Uncontrolled Keywords: | Paulitin, Metathesis, Synthesis, Amino compound, Enyne, Steric hindrance, Paulitine, Métathèse, Synthèse, Composés azotés, Enyne, Encombrement stérique |
| ID Code: | 1926 |
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| Deposited By: | Laurence Vidament |
| Deposited On: | 26 April 2007 |
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