(3S,4S)-4-Aminotetrahydrofuran-3-ol is a chiral, non-natural aminocyclitol derivative. It features a tetrahydrofuran ring substituted with both an amino group and a hydroxyl group, making it a versatile and valuable chiral building block in organic synthesis. This compound is primarily utilized as a key intermediate in the synthesis of nucleoside analogues and other bioactive molecules. Its structural motif is particularly important in the development of antiviral and anticancer agents, where it serves as a sugar or pseudosugar mimic to modify the properties of nucleoside drugs. The defined stereochemistry at the 3- and 4-positions is crucial for its biological activity and interaction with target enzymes. As a specialized chiral synthon, it is not a common, general-purpose reagent. Its synthesis and application are predominantly focused on medicinal chemistry research and the production of high-value pharmaceutical intermediates.