(S)-trans-4-Phenyl-3-buten-2-ol is a chiral allylic alcohol with the molecular formula C10H12O. It is characterized by a trans-configured double bond conjugated with a phenyl ring and a secondary alcohol group at the benzylic position. This compound is a versatile chiral building block in organic synthesis, particularly valued for its stereodefined structure. Its primary application is as a key intermediate in the synthesis of various biologically active molecules and natural products. The chiral center and the reactive olefin moiety make it a useful precursor for asymmetric transformations, including Sharpless asymmetric epoxidation and other stereoselective reactions to construct more complex chiral frameworks. It serves as a starting material or intermediate in the preparation of pharmaceuticals, fragrances, and fine chemicals. The compound is typically handled under inert atmosphere due to the potential sensitivity of the allylic alcohol system. It is used in research and development settings where high enantiomeric purity is required for the synthesis of target molecules with specific stereochemistry.