Tetrahydropyran is widely used as a solvent and reaction intermediate in organic synthesis. Its stability and polarity make it suitable for various chemical transformations, especially in pharmaceutical and fine chemical manufacturing. It serves as a protective group for alcohols in the form of tetrahydropyranyl (THP) ethers, allowing selective reactions at other functional sites in complex molecules. This protecting group is easily introduced and removed under mild acidic conditions, making it valuable in multi-step synthesis. Additionally, tetrahydropyran rings are structural motifs in numerous bioactive compounds and natural products, contributing to their use in drug design and development.