Inverse electron-demand Diels–Alder (IEDDA) reactions have gained a wide popularity as synthetic tool for the assembly of complex carbocyclic and heterocyclic products, as well as natural products, and drug-like scaffolds. Electron-deficient heterocyclic azadienes have proven to be useful reagents for IEDDA reactions with electron-rich dienophiles, providing a rapid access to a wide range of highly substituted heterocyclic systems. Reactions of azadienes with classical enamines, enol esters, and thioenol esters, as well as with amidines and guanidines have been reported. 1,2-Diazines, 1,2,4-triazines, and 1,2,4,5-triazines can be regarded as masked azadienes. Their reactions with dienophiles generally involve the formation of a bridged intermediate and subsequent extrusion of nitrogen (N2). In case of 1,3,5-triazines, elimination of a nitrile is observed. For example, CF3-containing electronpoor heterocyclic azadienes, such as 3,6-bis(trifluoromethyl)-1,2,4,5-tetrazine and 3,6-bis(trifluoromethyl)-1,2,4-triazine, were recently explored for the assembly of heterocyclic and carbocyclic frameworks. We have reported the synthesis of annulated 2,6-bis(trifluoromethyl)pyrimidines and the corresponding nucleosides of purine isosteres by the IEDDA reaction of 2,4,6-tris(trifluoromethyl)-1,3,5-triazine with electron-excessive heteroaromatic amines, anilines, and enamines. Based on these results, and on our experience related to the chemistry of 1,3-bis(trimethylsilyloxy)-1,3-butadienes, we decided to study the reaction of the latter with 2,4,6-tris(trifluoromethyl)-1,3,5-triazine (2). We considered that this reaction may produce a novel synthetic access to 2(2,6-bis(trifluoromethyl)pyrimidin-4-yl)acetate derivatives 3, which to date have only scarcely been reported in the literature. In analogy to the known transformations of enol esters and silyl enol ethers, it was expected that the reaction of 2,4,6-tris(trifluoromethyl)-1,3,5-triazine (2) with 1,3-bis(trimethylsilyloxy)-1,3-butadiene 1a would deliver pyrimidine 3. To our surprise, the reaction followed an unusual pathway and led to the formation of g-pyridone 4a as the major product in 78% yield (Table 1). The reaction was carried