RESUMEN
We report a new asymmetric synthetic method for (-)-swainsonine utilizing a chiral oxazoline precursor. The key features in this strategy are the diastereoselective oxazoline formation reaction catalyzed by palladium(0), diasteroselective dihydroxylation, and the stereocontrolled allylation reaction with TiCl(4).
Asunto(s)
Swainsonina/síntesis química , Antineoplásicos Fitogénicos/síntesis química , Antineoplásicos Fitogénicos/química , Oxazoles/química , Estereoisomerismo , Especificidad por Sustrato , Swainsonina/químicaRESUMEN
A concise, stereocontrolled synthesis of (+)-polyoxamic acid was achieved. Starting from trans-oxazoline as a chiral building block, the key step involves diastereoselective oxazine formation catalyzed by palladium(0).
Asunto(s)
Aminoácidos/síntesis química , Oxazinas/síntesis química , Azúcares Ácidos/síntesis química , Aminoácidos/química , Conformación Molecular , Oxazinas/química , Estereoisomerismo , Azúcares Ácidos/químicaRESUMEN
The enantioselective total synthesis of (-)-anisomycin, a potent antibiotic agent, has been achieved. The key steps are a Pd(0)-catalyzed stereoselective intramolecular oxazine formation from d-tyrosine and pyrrolidine formation by catalytic hydrogenation of the oxazine.
Asunto(s)
Anisomicina/síntesis química , Antibacterianos/síntesis química , Oxazinas/síntesis química , Paladio/química , Anisomicina/química , Antibacterianos/química , Catálisis , Estructura Molecular , Oxazinas/química , Pirrolidinas/química , Tirosina/químicaRESUMEN
In this study, we explored a convenient and concise route for synthesis of D-erythro-sphingosine 1 from commercially available and cheap L-serine. The key steps are simple preparation of amino ketone 5 from Weinreb amide 3 and high diastereoselective reduction of amino ketone 5 to give the natural erythro-(anti-) isomer.
Asunto(s)
Proteína Quinasa C/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/síntesis química , Esfingosina/análogos & derivados , Tecnología Farmacéutica/métodos , Amidas/síntesis química , Química Farmacéutica , Cetonas/síntesis química , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Estructura Molecular , Oxidación-Reducción , Inhibidores de Proteínas Quinasas/farmacología , Serina/química , Espectroscopía Infrarroja por Transformada de Fourier , Esfingosina/síntesis química , Esfingosina/farmacología , EstereoisomerismoRESUMEN
In this study, we explored a convenient and concise route for synthesis of L-threo-sphingosine, D-threo-sphingosine, L-threo-sphinganine and D-threo-sphinganine from commercially available L- or D-serine. The key steps are the simple preparation of trans-oxazoline and intermolecular olefin cross metathesis.