Identify the most suitable reagent for the following conversion:

Step-by-step solution

From the given reaction, we can observe that the - OH group is replaced by a - Cl atom with retention of configuration (both the - CH ₃ and the incoming - Cl are on solid wedges, meaning they are cis to each other, just like in the reactant). Let us analyze the given reagents: 1. SOCl ₂ : In the absence of a base like pyridine, the reaction of an alcohol with thionyl chloride proceeds via the S_N i (internal nucleophilic substitution) mechanism. This mechanism involves the formation of a chlorosulfite ester interme