Selectivity in C-alkylation of dianions of protected 6-methyluridine

• Ngoc Hoa Nguyen,
• Christophe Len,
• Anne-Sophie Castanet and
• Jacques Mortier

Beilstein J. Org. Chem. 2011, 7, 1228–1233, doi:10.3762/bjoc.7.143

• , Transformations intégrées de la matière renouvelable, EA 4297 UTC/ESCOM, 1 allée du réseau Jean-Marie Buckmaster, 60200 Compiègne, France 10.3762/bjoc.7.143 Abstract A regioselective synthesis of 6-ω-alkenyluridines 3, precursors of potent antiviral and antitumor cyclonucleosides 5, is described. While ω-alkenyl

• 3-bromocamphor was used as an electrophile. The corresponding C5-alkylated uridine derivative was obtained as the only recovered product, in low yield (23%), besides the unreacted substrate. Having these precedents in mind, we decided to investigate the preparation of 6-ω-alkenyluridines 3 by

• performed with fully TBDMS-protected ribofuranose nucleosides to allow better regiochemical control and to prevent nucleophilic attack of the base on the sugar moiety [48]. Conclusion In summary, a straightforward approach to 6-ω-alkenyluridines 3 from readily available protected uridine 1 is proposed