Studies directed toward introduction of N6-isopentenyladenosine and its 2-methylthio analogue into oligoribonucleotides.

A new efficient route of i6A and ms2i6A synthesis, especially useful for the preparation of i6A-containing oligoribonucleotides eg. Api6A has been proposed. The method is based on aminolysis of a 6-methylsulfonylpurine system formed by oxidation of its 6-methylthio precursor.