Prebiotic chemistry : Extension of an RNA primer can produce 2′‐5′ and 2′‐5′ phosphodiesters. In situ monitoring by NMR spectroscopy provides an unbiased view of the regioselectivity of this reaction and demonstrates how strongly template and leaving group favor the natural isomer.
ro-2-methyl imidazolides on standard oligonucleotide templates has been studied extensively. Here, we describe experiments with templates in which inosinicacid (I) is substituted for guanylicacid, or 2,6-diaminopurine nucleotide (D) for adenylicacid. We find that the substitution of I for G in a template is strongly inhibitory and prevents any incorporation of C into internal positions in the oligomeric