A practical procedure for the preparation of chiral 2-S-substituted-2H- pyran-3(6H)-ones is described. According to the reaction conditions, 1,5-anhydro-2,3,4-tri-O-acetyl-d-threo-pent-1-enitol (1) reacted with thiophenol under Lewis acid catalysis to afford the polysubstitution product 1,5-anhydro-2,3,4-tri-S-phenyl-2,3,4-trithio-d,l-threo-pent-1-enitol (2) or phenyl 2,4-di-O-acetyl-3-deoxy-1-thio-α- and β-d-glycero-pent-2- enopyranoside (3 and 4, respectively). The iodine-promoted addition of thiophenol or α-toluenethiol to 1 gave (2S)-2-phenylthio-2H-pyran-3(6H)- one (5) or its 2-benzylthio analogue 6, but these products showed low enantiomeric excesses (ee ∼40-60%). However, dihydropyranone 5 with high optical purity (ee >94%) was successfully obtained by treatment of 4 with iodine in acetonitrile. On the other hand, it was established that the benzylthio group of 5 exerts high stereocontrol in reduction and cycloaddition reactions performed on the α,β-unsaturated carbonyl system. © 2005 Elsevier Ltd. All rights reserved.
Documento: | Artículo |
Título: | Sugar-derived 2-S-substituted-2H-pyran-3(6H)-ones: Synthesis and reactivity |
Autor: | Capaccio, C.A.I.; Varela, O. |
Filiación: | CIHIDECAR-CONICET, Departamento de Química Orgánica, Pabellón II, 1428, Buenos Aires, Argentina |
Palabras clave: | Dihydropyranone; Glycosylations; Iodine; Lewis acids; Thiols; Catalysis; Iodine; Reduction; Substitution reactions; Synthesis (chemical); Dihydropyranone; Glycosylations; Lewis acids; Polysubstitution; Thiols; Sugar (sucrose); 1,5 anhydro 2,3,4 tri o acetyl dextro threo pent 1 enitol; 1,5 anhydro 2,3,4 tri s phenyl 2,3,4 trithio dextro,levo threo pent 1 enitol; 2 benzylthio 2h pyran 3(6h) one; 2 phenylthio 2h pyran pyran 3(6h) one; acetonitrile; alcohol derivative; carbonyl derivative; iodine; Lewis acid; phenyl 2,4 di o acetyl 3 deoxy 1 thio alpha dextro glyceropent 2 enopyranoside; phenyl 2,4 di o acetyl 3 deoxy 1 thio beta dextro glyceropent 2 enopyranoside; pyran derivative; pyranoside; sugar; thiol derivative; thiophenol; unclassified drug; article; catalysis; chirality; cycloaddition; enantiomer; priority journal; stereochemistry; synthesis; Pentoses; Phenols; Pyrans; Stereoisomerism; Sulfhydryl Compounds |
Año: | 2005 |
Volumen: | 340 |
Número: | 13 |
Página de inicio: | 2104 |
Página de fin: | 2110 |
DOI: | http://dx.doi.org/10.1016/j.carres.2005.05.024 |
Título revista: | Carbohydrate Research |
Título revista abreviado: | Carbohydr. Res. |
ISSN: | 00086215 |
CODEN: | CRBRA |
CAS: | acetonitrile, 75-05-8; iodine, 7553-56-2; thiol derivative, 13940-21-1; thiophenol, 108-98-5; Pentoses; Phenols; Pyrans; Sulfhydryl Compounds; thiophenol, 108-98-5 |
Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00086215_v340_n13_p2104_Capaccio |