(3S,4R)-1-tert-butyl 3-ethyl 4-hydroxypyrrolidine-1,3-dicarboxylate is a chemical compound characterized by its pyrrolidine ring substituted with tert-butyl, ethyl, and hydroxy moieties at positions 1, 3, and 4, respectively. Commonly known as TBD, this compound possesses distinct structural features that render it valuable in organic synthesis and medicinal chemistry. With its chiral centers and functional groups, TBD serves as a versatile intermediate in the preparation of various pharmaceuticals, agrochemicals, and specialty chemicals, contributing to the synthesis of diverse molecular architectures.