Final answer:
The oxymercuration-demercuration reaction is a regioselective and stereoselective process that typically follows Markovnikov's rule for regioselectivity, and leads to an anti-addition in stereoselectivity.
Step-by-step explanation:
The oxymercuration-demarcuration reaction is both stereoselective and regioselective. When it comes to regioselectivity, oxymercuration-demarcuration typically follows Markovnikov's rule, where the more substituted carbon atom in the double bond of an alkene is the one that gets the hydroxyl group. This occurs through the intermediacy of a mercurinium ion, a stabilized carbocation that dictates the more favorable site for nucleophilic attack. As for stereoselectivity, the addition of water in the demercuration step is not stereospecific; however, the reaction overall is anti-stereoselective, meaning that the hydroxyl group and the hydrogen will be added on opposite sides of the double bond. In the literature, these concepts of stereoselectivity and regioselectivity are also applied to other electrophilic additions and reactions involving the opening of epoxide rings, as seen in the synthesis of various compounds. Chemical manipulations often rely on the principles of regioselective and stereoselective reactions, such as aromatic substitutions, alcohol protections/deprotections, and the formation/removal of various protecting groups.