A new method for deprotecting acetyl groups of blocked purine nucleosides has been established by using tri-n-butyltin hydride (n-Bu3SnH) in the presence of α, α′-azobisisobutyronitrile (AIBN) without affecting OTs group.
SchwartzA.L., and LernerL. M., J. Org. Chem., 1975, 40, 24.
5.
IshidoY., NakazakiN., and SakairiN., J. Chem. Soc. Perkin I, 1979, 2088.
6.
WatanabeK.A., ReichmanU., ChuC. K., HollenbergD. H., and FoxJ. J., J. Med. Chem., 1980, 23, 1088.
7.
A similar cleavage of benzoates by tin hydride has been reported. See: KellyD.R., MahdiJ. G., Tetrahedron Lett., 2002, 43, 511.
8.
UenoY., TanakaC., and OkawaraM., Chem. Lett., 1983, 795.
9.
For entry 4: After refluxing at 75°C for 4h, 2′-OTs-3′,5′-di-O-acetyl-2-amino-6-chloropurine nucleoside was converted into 2′-OTs-3′,5′-di-O-acetyl-2-aminopurine nucleoside.
