Oligoribonucleotide Synthesis. VI. Selective Deblocking of the 5-O-Triphenylmethoxyacetyl Grouping in Protected Dinucleotides

Synthesis and 5′-deblocking of the triphenylmethoxyacetyl grouping in N-benzamido-dinucleotide derivatives, UpA, UpC, GpG, GpC, ApU, ApC, CpA, UpAp, and ApUp, are described. Alkaline cleavage behavior of the majority correlated well with the data found for similarly protected parent nucleosides. Those containing adenine residues adjacent to cytosine showed slow de-O-esterification and accelerated de-N-benzoylation, while those containing 3′-monophosphates showed enhanced de-O-esterification.