Deepoxidation

Deepoxidation is a chemical transformation that converts epoxide rings into other functionalities by opening the oxirane ring, thereby removing the epoxide functionality from a molecule. The term is not universally standardized and is encountered in polymer chemistry and biomass processing to describe extensive opening or reduction of epoxide groups.

The primary routes are: acid-catalyzed ring-opening by water or alcohols to form vicinal diols or beta-hydroxy ethers; and reductive opening using hydride donors or hydrogenation to yield alcohols or more reduced products. In acidic hydrolysis, attack occurs at the more substituted carbon, leading to trans-1,2-diols for simple epoxides. In basic or nucleophilic conditions, other products may form. Reductive deepoxidation aims to remove oxygen as water or alcohols, yielding saturated products.

In polymers and materials, deepoxidation can convert epoxy-functional sites to polyols, affecting crosslink density, flexibility, and processing. In biomass and vegetable oil chemistry, deepoxidation or subsequent opening of epoxidized oils produces polyols useful for polyurethanes and lubricants.

Practical considerations include selectivity, compatibility of functional groups, and potential side reactions. Safety concerns center on the reactivity of epoxides and acids or reducing agents used.