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Síntesis total asimétrica del esteroide reorganizado Phomarol habilitado por una ciclización biomimética S_N2'

Xudong Wang¹, Ganlin Huang¹, Yun Wang¹

¹CAS Key Laboratory of Synthetic Chemistry of Natural Substances, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Lingling Road, Shanghai 200032, China.

Journal of the American Chemical Society

|April 12, 2023

Resumen

Los investigadores sintetizaron el Phomarol, un producto natural complejo, utilizando un enfoque convergente de 13 pasos. Esta síntesis presenta transformaciones clave como la aliboración y la electrociclado, ofreciendo información sobre la química de los esteroides.

Área de la Ciencia:

Química orgánica
Síntesis de productos naturales
Síntesis estereoselectiva

Sus antecedentes:

Phomarol es un bioesteroide estructuralmente único.
Posee un ciclohepteno-1,3-diol pseudo-simétrico, un anillo B aromático y un anillo tetrahidropirano funcionalizado.

Objetivo del estudio:

Para reportar una síntesis concisa y eficiente del producto natural Phomarol.
Para explorar las transformaciones químicas clave para la construcción de esqueletos complejos de esteroides.

Principales métodos:

Enfoque de acoplamiento de fragmentos convergentes.
La síntesis en 13 pasos comienza con la sitolactona.
Reacciones clave: aliboración diastereoselectiva, eliminación descarboxilada, hidroxilación C-H, ciclización biomimética S_N2', electrociclado 6π.

Principales resultados:

Síntesis exitosa de Phomarol en 13 pasos.
Demostración de una nueva cascada de ciclización de la migración silílica/intramolecular S_N2' para la formación de anillos tetrahidropiranos.
Elucidación del mecanismo para el paso clave de ciclización.

Conclusiones:

La vía sintética desarrollada proporciona un acceso eficiente al Phomarol.
Los estudios mecánicos revelan una vía única para construir el anillo de tetrahidropirano en la síntesis de Phomarol.

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