AbstractPhotochemical cycloaddition of 6‐azauracil derivatives to enol acetates yields hydrolytically labile bicyclic azetidines which decompose in good to excellent yield to 5‐substituted‐5,6‐dihydro‐6‐azauracils. These compounds can in turn be oxidized by bromine to the 5‐substituted‐6‐azauracil. This reaction sequence has also been applied to 2′,3′,5′‐tri‐o‐benzoyl‐6‐azauridine resulting in a 60% overall yield of the functionalized nucleoside derivative. The three‐step procedure reported here affords a simple method for carboncarbon bond formation at the 5‐position of 6‐azauracil and