Oligoribonucleotide synthesis. XI. Improved preparation of 2′-O-tetrahydropyranyl derivatives of guanosine and adenosine necessary for insertion in phosphotriester synthesis

Abstract

Treatment of N2-benzoyl-2′,3′,5′-O-triacetylguanosine and 2′,3′,5′-O-triacetyladenosine with buffered hydrazine gave equilibrium mixtures of N2-benzoyl-2′(3′),5′-diacetylguanosine and 2′(3′),5′-diacetyladenosine, greatly enriched in the desired 3′-acetates. Fractional crystallization effected recovery of pure 3′,5′-diacetates in 60% yields. From these were prepared the 2′-O-tetrahydropyranyl derivatives required for guanosine and adenosine insertion in phosphotriester oligonucleotide synthesis.