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Síntesis total de tioalcaloides de nufar oxidado de manera no simétrica mediante ensamblaje de tiolano catalizado por

Jacob J Lacharity¹, Jeremy Fournier¹, Ping Lu¹

¹Department of Chemistry and Biochemistry, University of California , Santa Barbara, California 93106, United States.

Journal of the American Chemical Society

|September 16, 2017

Resumen

Este estudio presenta la primera síntesis total asimétrica de dos sesquiterpenos diméricos, (+) -6-hidroxiobinofaridina y (-) -6-hidroxionioflutina, de lirios amarillos. Se empleó una nueva estrategia de reordenamiento de Stevens para construir el núcleo único de tiaspirano.

Área de la Ciencia:

Química orgánica
Síntesis de productos naturales
Química medicinal

Sus antecedentes:

Los lirios de agua amarillos (género Nuphar) producen sesquiterpenos diméricos con estructuras hemiaminadas.
Estos alcaloides, que incluyen 6-hidroxiobinofaridina y 6-hidroxionioflutina, poseen núcleos complejos de bi-spirocíclicos tetrahidrotiofeno.
Las rutas sintéticas anteriores y las propuestas se basan en la dimerización simétrica de monómeros.

Objetivo del estudio:

Para lograr la primera síntesis total asimétrica de (+) -6-hidroxiobinofaridina y (-) -6-hidroxionioflutina.
Desarrollar una nueva estrategia sintética para construir el núcleo de tiaspirano.
Para acceder a los sesquiterpenos diméricos asimétricamente oxidados.

Principales métodos:

La síntesis total asimétrica.
Stevens reorganización de un yélido de sulfonio.
Generación in situ de un ylide de sulfonio mediante el acoplamiento cobre-carbeno y tietano espirocíclico.
Acoplamiento de monómeros no simétricos.

Principales resultados:

Síntesis asimétrica total exitosa de la (+) -6-hidroxiobinofaridina y la (-) -6-hidroxionioflutina.
Construcción del anillo central bis-espirocíclico de tetrahidrotiofeno utilizando un nuevo reordenamiento de Stevens.
Síntesis por primera vez del producto oxidado asimétricamente (-) -6-hidroxionioflutina.
Demostración de una estrategia sintética distinta de la dimerización de monómeros simétricos.

Conclusiones:

La estrategia sintética desarrollada proporciona un acceso eficiente a los sesquiterpenos diméricos complejos.
Este enfoque ofrece una nueva vía para los productos naturales sustituidos de manera asimétrica.
La síntesis destaca la versatilidad del reordenamiento de Stevens en la construcción de arquitecturas moleculares desafiantes.

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