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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Morita-Baylis-Hillman em síntese orgânica. 1) Estudos para a síntese de alcalóides das Amaryllidaceae. 2) Síntese diastereosseletiva de beta-hidróxi-alfa-aminoésteres / Morita-Baylis-Hillman in organic synthesis. 1) Studies for the synthesis of Amaryllidaceae alkaloids. 2) Diastereoselective synthesis of beta-hydroxy-alfa-aminesters

Ullah, Hamid, 1982- 26 August 2018 (has links)
Orientador: Fernando Antonio Santos Coelho / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-26T02:39:26Z (GMT). No. of bitstreams: 1 Ullah_Hamid_D.pdf: 4284540 bytes, checksum: 3371acfc6c696bf069405b0e69378616 (MD5) Previous issue date: 2014 / Resumo: Esse trabalho de doutorado visou explorar o potencial sintetico da reacao de Morita-Baylis- Hillman (MBH) na preparacao de intermediarios sinteticos, que possam ser utilizados na sintese total de produtos naturais. Na primeira parte deste trabalho, realizamos estudos para a sintese total do alcaloide (})-Plicamina e de outros alcaloides, isolados de plantas da familia das Amaryllidaceae, estruturalmente semelhantes. Desenvolvemos uma nova abordagem sintetica para esse trabalho, que culminou com o estabelecimento de uma nova metodologia para a preparacao de ¿À-hidroxi-¿¿-amino esteres. A ozonolise, oximacao e subsequente reducao do aduto de Morita-Baylis-Hillman sililado, proveniente do bromopiperonal, forneceu um ¿À-hidroxi-¿¿-aminoester, com estereoquimica relativa anti, e elevada diastereosseletividade. Esse foi transformado em um intermediario avancado (¿À-hidroxi-¿¿-aminoester N-alquilado) para a sintese do alcaloide, ja que possui todos os grupos funcionais necessarios para atingir o alvo final. Na segunda parte desse trabalho, avaliamos o escopo da nova metodologia de sintese de ¿À-hidroxi-¿¿-aminoesteres. Essa metodologia, simples e direta, permitiu a preparacao de diferentes ¿À-hidroxi-¿¿-aminoesteres, com elevada diastereosseletividade em 4 etapas e bons rendimento globais. Esse e o primeiro exemplo de sintese ¿À-hidroxi-¿¿-aminoesteres, a partir de adutos de Morita-Baylis- Hillman (MBH) / Abstract: This work of doctorate explored the synthetic potential of Morita-Baylis-Hillman (MBH) reaction in the preparation of synthetic intermediates that could be utilized in the synthesis of natural products. In the first part of this work we performed studies towards the total synthesis of (±)-Plicamin and the other structurally related alkaloids, isolated from the plants of the Amaryllidaceae family. We developed a new synthetic approach, which culminated with the establishment of the new methodology for the preparation of â-hydroxy-á-amino esters. The ozonolysis, oxymation and subsequent reduction of the silylated Morita-Baylis-Hillman adduct, obtained from bromopiperonal, furnished a â-hydroxy-á-aminoester, with a relative stereochemistry anti, in high diastereoselectivity. This was transformed further to an intermediate (N-alkylated â-hydroxy-á-aminoester), which has almost all the necessary functional groups to allow the synthesis of the target alkaloid. In the second part of this work we evaluated the scope of the new methodology of the synthesis of â-hydroxy-á-aminoester. This simple and direct methodology allowed us the preparation of different â-hydroxy-á-aminoesters, with high diastereoselectivities, in four steps with good global yield. Additionally, this work demonstrates a first example the synthesis of â-hydroxy-á-aminoesters from the Morita-Baylis- Hillman (MBH) adducts / Doutorado / Quimica Organica / Doutor em Ciências

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