3-Oxo-1,3-oxathiolanes-synthesis and stereochemistry.
Magn Reson Chem
; 46(3): 244-9, 2008 Mar.
Article
en En
| MEDLINE
| ID: mdl-18236438
The compound 3-oxo-1,3-oxathiolane (6) and its cis - and trans - 2-methyl (7,8), 4-methyl (9,10), 5-methyl (11,12) and 2-p-nitrophenyl (13,14) derivatives were prepared by oxidizing the corresponding 1,3-oxathiolanes (1-5) with NaIO4 in water. The oxides were purified and their isomers separated using thin layer chromatography. The structural characterization was carried out with 1H NMR spectroscopy and molecular modeling. Compounds 8-10, 12, and 14 attain the half-chair type conformation with O1 above and C5 below the plane (HC1), but 6, 7, 11, and 13 are, for steric reasons, the mixtures with the alternative half-chair (HC2), where O1 is below and C5 above this plane. Accordingly, 6 appears based on the values of experimental coupling constants as an 81:19, 7 as a 37:63, 11 as a 33:67 and 13 as a 54:46 mixture of HC1 and HC2, respectively. The relative energies of these conformations, the values of the vicinal H,H-coupling constants and 1H chemical shifts were estimated for compounds 6-12 also by computational methods and they support nicely the conclusions based on experimental data.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Óxidos
/
Compuestos de Sulfhidrilo
/
Simulación por Computador
/
Espectroscopía de Resonancia Magnética
Tipo de estudio:
Prognostic_studies
Idioma:
En
Revista:
Magn Reson Chem
Asunto de la revista:
QUIMICA
Año:
2008
Tipo del documento:
Article
País de afiliación:
Finlandia
Pais de publicación:
Reino Unido