Dimetalation of pyrazines. a one-pot synthesis of multisubstituted pyrazine C-nucleosides.
J Org Chem
; 66(14): 4783-6, 2001 Jul 13.
Article
en En
| MEDLINE
| ID: mdl-11442404
ABSTRACT
As a part of our efforts to pursue direct, convergent, and concise methodologies for the synthesis of pyrazine C-nucleosides, we have successfully established a sequential dilithiation-addition method, which allows one to introduce two different functional groups to a pyrazine ring in a one-pot fashion. 2,6-Dichloropyrazine was dilithiated at -100 degrees C and then allowed to react with an electrophile, such as bromine, iodine, or disulfides, followed by a reaction with a protected ribonolactone to afford C-nucleosides. After reduction and deprotection, tetrasubstituted pyrazine C-nucleosides, including 2,6-dichloro-3-iodo-5-(beta-D-ribofuranosyl)pyrazine and 2-bromo-3,5-dichloro-6-(beta-D-ribofuranosyl)pyrazine, were obtained. A tandem reaction sequence occurred when disulfides were used, resulting in the formation of 5,6-bis-methylthio-2-chloro-3-(beta-D-ribofuranosyl)pyrazine and 6-(beta-D-ribofuranosyl)-2,3,5-tris-phenylthiopyrazine.
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Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Pirazinas
/
Nucleósidos de Pirimidina
Idioma:
En
Revista:
J Org Chem
Año:
2001
Tipo del documento:
Article
País de afiliación:
Estados Unidos