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Síntesis Total de Diepoxi-ent-Diterpenoides de Kaurano Habilitados por una Cicloadición Intramolecular Iniciada por

Yin Li¹, Qilin Xue¹, Xiangbo Zhao¹

¹State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Lu, Shanghai 200032, China.

Journal of the American Chemical Society

|December 27, 2024

Resumen

Este estudio detalla las primeras síntesis totales enantioselectivas de cuatro diterpenoides de diepoxi-ent-kaurano. Una nueva estrategia utilizando un intermediario de enona de cabeza de puente [3.2.1] permitió la construcción de arquitecturas moleculares complejas.

Área de la Ciencia:

Química orgánica
Síntesis de productos naturales
Química de los diterpenoides

Sus antecedentes:

Los diterpenoides diépoxi-ent-kaurano son productos naturales complejos con un interés biológico significativo.
Las rutas sintéticas anteriores a estos compuestos fueron limitadas, lo que obstaculizó una mayor investigación.

Objetivo del estudio:

Para lograr las primeras síntesis totales enantioselectivas de cuatro diterpenoides específicos de diepoxi-ent-kaurano.
Desarrollar una nueva estrategia sintética para la construcción de diterpenoides policíclicos complejos.

Principales métodos:

Diseño estratégico de una captura regioselectiva y estereospecífica de un enón intermedio de cabeza de puente [3.2.1].
Reacción intramolecular de Diels-Alder atada y cascada de radicales catalizados por Ti (III).
Manipulaciones del estado de oxidación y formación de puente hemiketal en etapa tardía.

Principales resultados:

Síntesis totales enantioselectivas exitosas de (-) -Macrocalina B, (-) -Acetil-macrocalina B, (-) -Isoadenolina A y revisada (-) -Fillostacina I.
Elucidación de un mecanismo diradical por etapas para el paso clave de la cicloadición.
Demostración de una cascada de radicales de anillo abierto y anulación catalizada por el ciclobutano Ti (III).

Conclusiones:

La estrategia sintética desarrollada agiliza la síntesis de los diterpenoides diépoxi-ent-kaurano.
Este enfoque allana el camino para las síntesis modulares y la mayor exploración de estos productos naturales.
Destaca la utilidad de los intermediarios de enona de cabeza de puente [3.2.1] en la construcción de moléculas complejas.

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