Artículo
Stereospecific Synthesis of Pyrrolidines with Varied Configurations via 1,3-Dipolar Cycloadditions to Sugar-Derived Enones
Fecha de publicación:
05/2014
Editorial:
American Chemical Society
Revista:
Journal Of Organic Chemistry
ISSN:
0022-3263
Idioma:
Inglés
Tipo de recurso:
Artículo publicado
Clasificación temática:
Resumen
Enantiomerically pure pyrrolidines have been obtained by 1,3-dipolar cycloaddition of stabilized azomethine ylides and sugar enones (dihydropyranones) derived from pentoses. Thus, the S-enone (menthyl 3,4-dideoxy-(1S)-pent-3-enopyranosid-2-ulose) was prepared from d-xylose, while the R analogue was obtained from l-arabinose. The dipoles were generated in situ from α-arylimino esters of common amino acids (glycine, alanine, or phenylalanine) and aromatic aldehydes (benzaldehyde, 3-formylpyridine and 4-methoxybenzaldehyde). Under optimized conditions, the cycloaddition reactions were highly diastereo- and regioselective to yield, in most of the cases, a very major adduct of the 16 theoretically possible. The diastereoselectivity relies on the strict stereocontrol exerted by the stereogenic center of the pyranone. Thus, the (S)-enone, derived from d-xylose, gave tetrasubstituted pyrrolidines having a defined stereochemistry for the four stereocenters of the ring, while they had the opposite configuration when starting from the (R)-dihydropyranone. Furthermore, some endo-cycloadducts underwent isomerization of the carbons vicinal to the nitrogen atom to afford pyrrolidines with a rather unusual stereochemistry for the direct dipolar cycloadditions.
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Articulos(CIHIDECAR)
Articulos de CENTRO DE INVESTIGACIONES EN HIDRATOS DE CARBONO
Articulos de CENTRO DE INVESTIGACIONES EN HIDRATOS DE CARBONO
Citación
Oliveira Udry, Guillermo Alejandro; Repetto, Evangelina; Varela, Oscar Jose; Stereospecific Synthesis of Pyrrolidines with Varied Configurations via 1,3-Dipolar Cycloadditions to Sugar-Derived Enones; American Chemical Society; Journal Of Organic Chemistry; 79; 11; 5-2014; 4992-5006
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