The one‐pot preparation of azanucleotide analogues from proline derivatives has been achieved by a sequential radical decarboxylation/phosphorylation process. The process proceeded under mild conditions, giving high yields of the nucleotide analogues. Remarkably, the stereoselectivity of the reaction can be controlled by using different oxygen and nitrogen substituents at C‐4 to give preferentially either the 2,4‐cis or 2,4‐trans products. In this way, the diastereomeric cis/trans ratio can be shifted from 98:2 to 15:85.