Synthesis and Restricted Conformation of 3′,5′-O-(Di-t-butylsilanediyl)ribonucleosides

The reaction of ribonucleosides with di-t-butylsilyl diester such as dinitrate, diperchlorate and ditriflate in DMF gave selectively 3′,5′-O-(di-t-butylsilanediyl)ribonucleosides in high yield. The conformation analysis by 1H NMR spectroscopy and X-ray crystallography showed that the product has a restricted conformation analogous to that observable in 3′,5′-cyclic nucleotides.