(S)-(-)-Propylene oxide is a chiral epoxide serving as a key intermediate in asymmetric synthesis, particularly in the pharmaceutical industry for producing enantiomerically pure drugs and chiral building blocks. It is used in the manufacture of optically active compounds such as (S)-1,2-propanediol and various beta-blockers, antidepressants, and agrochemicals where stereochemistry is critical. Its high enantiomeric purity enables precise control in reactions like epoxide ring-opening, facilitating the creation of single-enantiomer products essential for efficacy and safety in medications. Additionally, it finds niche applications in the synthesis of chiral polymers, surfactants, and additives for specialty coatings and adhesives in fine chemicals.