What is the process of adding hydroxyl groups to both aliphatic and aromatic compounds generally called?

The process of adding hydroxyl groups to both aliphatic and aromatic compounds is known as hydroxylation. Hydroxylation involves introducing one or more hydroxyl (-OH) groups into a molecule, which can dramatically alter its chemical properties and reactivity. This process is crucial in various chemical reactions and biochemical pathways, as hydroxyl groups can significantly enhance the solubility and reactivity of organic compounds.

Hydroxylation can occur through different mechanisms, including enzyme-catalyzed reactions in biological systems, leading to the formation of products that may have different biological activities or toxicities. This addition is essential in metabolic processes, such as the drug metabolism in the liver, where hydroxylation can facilitate the excretion of foreign compounds from the body.

The other options represent different types of chemical reactions: deacetylation involves the removal of an acetyl group, alkylation refers to the addition of alkyl groups to a molecule, and oxidation generally pertains to the increase in the oxidation state of an atom or molecule, often involving the addition of oxygen rather than hydroxyl groups. Hence, hydroxylation is specifically characterized by the incorporation of hydroxyl groups, making it the appropriate term for the described process.