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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Ciclización de Nazarov iniciada por la oxidación del peracido: la síntesis total de (+/-) -rocaglamida
John A Malona1, Kevin Cariou, Alison J Frontier
1Department of Chemistry, University of Rochester, Rochester, New York 14627, USA.
Journal of the American Chemical Society
|May 19, 2009
Resumen
Los investigadores lograron la síntesis total de aglafolina, ácido rocaglóico y rocaglamida. Este nuevo enfoque utiliza la ciclización de Nazarov y un intermediario de iones de oxicarbenio para una síntesis eficiente y diastereoselectiva.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Química sintética de la química sintética.
Sus antecedentes:
- La rocalamida y sus análogos son productos naturales con actividades biológicas significativas.
- Las rutas sintéticas anteriores a la rocaglamida y compuestos relacionados tienen limitaciones en eficiencia y estereoselectividad.
Objetivo del estudio:
- Desarrollar una nueva y eficiente síntesis total de aglafolina, ácido rocaglóico y rocaglamida.
- Explorar la utilidad de la ciclización de Nazarov en la construcción de la estructura central de estos productos naturales.
Principales métodos:
- Síntesis total empleando la ciclización de Nazarov.
- Generación de un intermediario de catión oxyallyl a través de la oxidación peracida de un éter de allenol.
- Formación de una especie inusual de iones de oxicarbenio.
Principales resultados:
- Se lograron síntesis totales exitosas y eficientes de aglafolina, ácido rocaglóico y rocaglamida.
- La vía sintética es altamente diastereoselectiva, controlando la estereoquímica de los productos finales.
- Se estableció una nueva estrategia distinta de las anteriores síntesis de rocaglamida.
Conclusiones:
- La estrategia sintética descrita proporciona una nueva y efectiva ruta hacia la rocaglamida y los productos naturales relacionados.
- El uso de la ciclización de Nazarov y el intermediario de iones de oxicarbenio generado representa un avance significativo en la metodología sintética.
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