Meldrum’s Acid 5-13C is a carbon-13 labeled derivative of Meldrum’s acid (2,2-dimethyl-1,3-dioxane-4,6-dione), where the 13C isotope is incorporated at the 5-position. This isotopically labeled compound is widely used as a versatile building block in organic synthesis, particularly in the preparation of labeled intermediates for pharmaceuticals, agrochemicals, and materials science. The 13C labeling enables precise tracking in mechanistic studies, NMR spectroscopy, and metabolic research. Its high isotopic purity ensures reliable results in tracer experiments. The compound retains the reactivity of Meldrum’s acid, facilitating condensations, cyclizations, and other transformations while providing the analytical advantages of isotopic labeling. Suitable for researchers requiring stable isotope incorporation in synthetic pathways.