Introduction
Within the realm of organic chemistry, halohydrins represent a distinct functional group characterized by the bonding of a halogen atom and a hydroxyl group to two neighboring carbon atoms, which are otherwise linked to hydrogen or alkyl groups. This classification is strictly reserved for saturated structures. The family of halohydrins is further divided into subcategories based on the specific halogen involved, namely chlorohydrins, bromohydrins, fluorohydrins, and iodohydrins.
The synthesis of halohydrins typically involves the electrophilic addition of a halogen to an alkene in an aqueous environment. This reaction mechanism, akin to halogen addition, is characterized by the anti addition of the halogen and hydroxyl groups, resulting in a trans configuration between the newly incorporated X and OH groups. The process exemplifies a fundamental reaction type within organic synthesis, showcasing the versatility of halohydrins as intermediates.
Reaction
Regioselectivity: Markovnikov
Stereospecificity: anti
Intermediate: carbocation
The same also works if an alcohol is used instead of water, as shown below:
Mechanisms
Mechanism with water:
Mechanism with alcohol:
