The reaction of converting an alcohol to an alkyl halide using thionyl chloride (SOCl₂) is known as the "Darzens-Hantzsch method" or "Hunsdiecker reaction."
This reaction is commonly used for the conversion of alcohols, particularly primary and secondary alcohols, into alkyl chlorides. The reaction typically proceeds with inversion of configuration at the carbon bearing the hydroxyl group, but it's important to note that the stereochemical outcome can be influenced by the reaction conditions and the specific structure of the alcohol.
The use of pyridine as a base is commonly indicated in the reaction to facilitate the elimination step and ensure the reaction proceeds smoothly.