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| Author(s): |
Isac George Rosset
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Carlos. |
| Institution: | Universidade de São Paulo (USP). Instituto de Química de São Carlos (IQSC/BT) |
| Defense date: | 2015-03-13 |
| Examining board members: |
Antonio Carlos Bender Burtoloso;
Kleber Thiago de Oliveira;
Cristiano Raminelli;
Luiz Fernando da Silva Junior
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| Advisor: | Antonio Carlos Bender Burtoloso |
| Abstract | |
The first part of this work describes the preparation of a new HWE olefination reagent to prepare diazoketones α, β-unsaturated with Z geometry and its application in the synthesis of functionalized piperidine cores. After the optimization of the HWE reaction using benzaldehyde as a standard it was possible to prepare the desired Z isomer in 92% (Z:E 9:1). The key reaction for formation of the piperidine cores, N-H metal-catalyzed insertion performed to give a yield of up to 70%. The versatility of the methodology was demonstrated by an application to the synthesis of the natural product (±)-3,4,5-triidroxypiperidine and studies in the synthesis of (-)-1-deoxy-altronojirimicine. The chemistry of α, β-unsaturated diazoketones was also employed in the synthesis of another natural product, the alkaloid (±)-preussine. The employed route showed high stereoselectivity in the key-reaction (Stevens Rearrangement) as well as in the subsequent reduction of the formed ketone with a reducing agent (L-Selectride) giving an overall yield of 40%. We also tried to extend the methodology to prepare trisubstituted α, β-unsaturated diazoketones from the reaction with the olefination reagent and ketones. However, after several attempts no fruitful results were abtained. (AU) | |
| FAPESP's process: | 10/18801-1 - DIVERGENT SYNTHESIS OF PYRROLIDINE ALKALOIDS FROM ALFA,BETAUNSATURATED DIAZOKETONES AS BIFUNCTIONAL REAGENTS. APPLICATION IN THE TOTAL SYNTHESIS OF (±)-PREUSSIN |
| Grantee: | Isac George Rosset |
| Support Opportunities: | Scholarships in Brazil - Doctorate |