Used as a key reagent in organic synthesis, particularly in the Horner-Wadsworth-Emmons (HWE) reaction, to produce α,β-unsaturated esters and olefins with high selectivity. Its phosphonate group stabilizes carbanions, enabling efficient carbon-carbon bond formation under mild conditions. Commonly applied in the synthesis of pharmaceuticals, agrochemicals, and fine chemicals where precise control over double bond geometry is required. Also serves as a building block in the preparation of complex molecules such as natural products and functionalized polymers. Its liquid form and good reactivity make it suitable for large-scale industrial processes.