Reactant (R). A substance that undergoes change in a chemical reaction. Reagent (A). A substance added to cause or accelerate a reaction Propose the Structure of the Starting Reactant [R1-S1]: With the initial step culminating in a cyclic pentane intermediate, deduce the structure of the initial reagent responsible for this transformation. (1 mark) Identify the Reagent [A1-S2] for Nitrile Reduction and Deduce the Product [R1-S2]: The second stage encompasses the reduction of a nitrile functional group. Identify the reagent responsible and, based on its reactivity, infer the structure of the resultant intermediate. (1 mark for reagent, 1 mark for structure) Determine the Structure of the Alkylating Derivative [R1-531