Polymerization of a monomeric guanosine derivative in a hydrogen- bonded aggregate

The adduct IIa, in which glycine is linked to the 3'-amino group of 3'-deoxyguanosine-5'-phosphate, condenses very efficiently in aqueous solution when treated with a water-soluble carbodiimide to give long oligomeric products. The corresponding cytidine derivative IIb yields a complex mixture of very short oligomers. We believe that the efficient condensation reaction occurs in a hydrogen-bonded tetrahelical aggregate of a type that is known to form with many guanosine derivatives.