The present invention provides nucleosides of formula (1) and oligonucleotides comprising at least on nucleoside of formula (2): Another aspect of the invention relates to a method of inhibiting the expression of a gene in cell, the method comprising (a) contacting and oligonucleotide of the invention with the cell; and (b) maintaining the cell from step (a) for a time sufficient to obtain degradation of the mRNA of the target gene.
