Ring closure is a chemical reaction that forms a cyclic structure from a linear molecule. This process often occurs in organic chemistry, where specific conditions, such as the presence of catalysts or heat, facilitate the formation of a ring. The resulting cyclic compound can exhibit unique properties compared to its linear counterpart. In many cases, ring closure is essential in the synthesis of complex molecules, including natural products and pharmaceuticals. For example, the formation of cyclohexane from hexene involves the closing of a carbon chain into a stable ring structure, which can significantly influence the compound's reactivity and stability.