Regioselective synthesis of long-chain ethers and their sulfates derived from methyl beta-D-galactopyranoside and derivatives via dibutylstannylene acetal intermediates.
Carbohydr Res
; 340(14): 2245-50, 2005 Oct 17.
Article
en En
| MEDLINE
| ID: mdl-16084504
ABSTRACT
A number of different conditions were investigated for the alkylation of the dibutylstannylene acetals of methyl beta-d-galactopyranoside with long-chain primary alkyl bromides, decyl, dodecyl, and tetradecyl bromide. The best yields of the major products, the 3-O-alkyl ethers, were obtained by reaction of the alkyl bromide with the monodibutylstannylene acetal in DMF in the presence of cesium fluoride for extended periods of time at moderate temperatures (65 degrees C). These products were always accompanied by minor amounts of the 3,6-di-O-alkyl derivative. Performing the reaction with excess alkyl halide on the bis(dibutylstannylene) acetal resulted in more of the 3,6-di-O-alkyl derivative, particularly for the shorter alkyl bromides, but this product was never predominant. Sulfation of the dibutylstannylene acetal of methyl 3-O-tetradecyl-beta-D-galactopyranoside resulted in the 6-sulfate in 96% yield.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Ésteres del Ácido Sulfúrico
/
Éteres
/
Metilgalactósidos
Idioma:
En
Revista:
Carbohydr Res
Año:
2005
Tipo del documento:
Article