The reactions of diethyl 2‐(dicyanomethylene)malonate, an electron‐deficient alkene, with donor‐activated and unactivated alkynes have been investigated. Moderately electron‐rich and unactivated alkynes undergo efficient formal [3+2] cycloaddition–rearrangement cascades to provide the corresponding penta‐2,4‐dien‐1‐one adducts in yields of up to 84 %. The structures of the solid dienone products were confirmed by X‐ray diffraction analysis. The buta‐1,3‐diene moieties in the dienones do not adopt planar s‐trans conformations but rather nonplanar geometries in which the two olefinic bonds are nearly orthogonal to each other. This transformation proceeds with excellent regioselectivity and with a wide range of alkynes without the need for a catalyst. Under the optimized reaction conditions, no competition with the [2+2] cycloaddition–retroelectrocyclization reaction (CA–RE) was observed.