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Síntesis total de la (+/-) -didehidrostemofolina (asparagamina A) y de la (+/-) -isodehidrostemofolina, también
Markus Brüggemann1, Andrew I McDonald, Larry E Overman
1Department of Chemistry, 516 Rowland Hall, University of California, Irvine, CA 92697-2025, USA.
Journal of the American Chemical Society
|December 11, 2003
Resumen
Se lograron las primeras síntesis totales de didehidrostemofolina e isodehidrostemofolina. Los pasos clave involucraron una reacción Diels-Alder y una reacción Aza-Cope-Mannich para construir el complejo marco molecular.
Área de la Ciencia:
- Química orgánica es la química orgánica.
- Química sintética de la química sintética.
- Química medicinal Química medicinal es el campo de la química medicinal.
Sus antecedentes:
- La stemofolina es un alcaloide complejo con actividades biológicas potenciales.
- Las rutas sintéticas eficientes hacia los análogos de la stemofolina son cruciales para la investigación posterior.
Objetivo del estudio:
- Informar las primeras síntesis totales de (+/-) didehidrostemofolina y (+/-) isodehidrostemofolina.
- Para establecer una vía sintética confiable para estos objetivos moleculares desafiantes.
Principales métodos:
- La síntesis comenzó con una reacción de Diels-Alder entre pirrolo y etil (E) -3-nitroacrilato.
- Los intermediarios clave, incluidos el 7-azabiciclo[2.2.1]heptanol y el 1-azatriciclo[5.3.0.04.10]decano, se formaron a través de la hidrogenación y las reacciones Aza-Cope-Mannich.
- Una secuencia posterior de 15 pasos completó la síntesis de las moléculas objetivo.
Principales resultados:
- Se lograron síntesis totales exitosas y por primera vez de (+/-) -didehidrostemofolina (1) y (+/-) -isodidehidrostemofolina (3).
- La estrategia sintética construyó de manera eficiente las intrincadas estructuras del núcleo policíclico de los alcaloides objetivo.
- Las reacciones Diels-Alder y Aza-Cope-Mannich demostraron ser fundamentales en el ensamblaje del marco molecular.
Conclusiones:
- La ruta sintética desarrollada proporciona acceso a la didehidrostemofolina y a la isodehidrostemofolina.
- Este trabajo sienta las bases para explorar las propiedades biológicas y desarrollar análogos de los alcaloides de stemofolina.
- Las síntesis reportadas demuestran el poder de las reacciones estratégicas de cicloadición y reordenamiento en la construcción de moléculas complejas.
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