3′,5′-Cyclic dinucleoside phosphates: undesirable intermediates in the phosphotriester approach to oligonucleotide synthesis

Abstract

Mild alkaline hydrolysis of (4a) gives the 3′,5′-cyclic dinucleoside phosphate (5a); more drastic alkaline hydrolysis of phosphotriester intermediates with free vicinal 5′- or 3′-hydroxy functions [(4a) and (7b), or (6a) and (8b)] leads to products with, respectively, 5′→ 5′- or 3′→ 3′-in addition to 3′→ 5′-internucleotide linkages.