Ethyl L-(-)-O-Tosyllactate is primarily used in organic synthesis as a chiral building block. It is particularly valuable in the preparation of optically active compounds, such as pharmaceuticals and agrochemicals, where stereochemistry plays a critical role in biological activity. The compound serves as an intermediate in the synthesis of complex molecules, enabling the introduction of specific chiral centers. Additionally, it is utilized in the development of peptides and other biologically active molecules, where its tosyl group can act as a protective group during synthetic processes. Its application extends to asymmetric synthesis, where it aids in creating enantiomerically pure substances, essential for high-precision chemical reactions.