A New Alkylation-Elimination Method for Synthesis of Antiviral Fluoromethylenecyclopropane Analogues of Nucleosides.
Tetrahedron
; 61(30): 7112-7116, 2005 Jul 25.
Article
em En
| MEDLINE
| ID: mdl-16801980
ABSTRACT
A new method for the synthesis of fluoromethylenecyclopropane nucleosides by alkylation-elimination procedure is described. Fluorination of methylenecyclopropane carboxylate 6 gave fluoroester 7. Treatment of 7 with phenylselenenyl bromide afforded the desired ethyl (E)-2-bromomethyl-1-fluoro-2-phenylselenenylcyclopropane-1-carboxylate 11 in 85% yield. DIBALH reduction of 11 gave 13, which after acetylation to 14 was reacted with 2-amino-6-chloropurine to give the 9-alkylated product 15 in 87% yield. Se-oxydation of 15 with hydrogen peroxide afforded 16, which underwent smooth elimination in a mixture of THF-DMF at 60 degrees C giving rise to a Z,E mixture of protected nucleosides 17. Deacetylation gave Z-1a and E-1a which were separated on a silica gel column. Both Z-1a and E-1a were converted into the respective guanine analogues Z-1b and E-1b.
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1
Coleções:
01-internacional
Base de dados:
MEDLINE
Idioma:
En
Revista:
Tetrahedron
Ano de publicação:
2005
Tipo de documento:
Article