The cyclization of arabinosyladenine-5'-phosphorimidazolide

When arabinosyladenine-5'-phosphorimidazolide is allowed to decompose in aqueous solution at room temperature and pH 7.2, depending on the buffer, 5-24% is converted to the 2',5'-cyclic phosphate (V). Although the extent of cyclization is much greater than for adenosine-5'-phosphorimidazolide, cyclization is less efficient than hydrolysis and so would not substantially decrease the efficiency of condensation reactions in aqueous solution. The significance of this result for prebiotic chemistry is discussed.