Outline all steps in the synthesis of propyne from acetylene using any needed organic or inorganic reagents.

Acetylene is an alkyne with the molecular formula C2H2. Its structure is H-C≡C-H. Propyne, on the other hand, is an alkyne with the molecular formula C3H4. Its structure is CH3-C≡C-H. Our goal is to synthesize propyne from acetylene, which involves adding a methyl (CH3) group to one of the carbon atoms in acetylene.

To add a methyl group to acetylene, we will use a two-step process involving formation of an organolithium compound followed by a reaction with a methyl electrophile. 1. Formation of the organolithium compound: Treat acetylene with n-butyllithium (n-BuLi) in an ether solvent such as diethyl ether. This deprotonates acetylene, resulting in the formation of the lithium acetylide ion (H-C≡C-Li+). \( \text{Acetylene} + \text{n-BuLi} \rightarrow \text{H-C} \equiv \text{C-Li}^+ + \text{n-BuH} \) 2. Reaction with methyl electrophile: Introduce a solution of iodomethane (CH3I) to the lithium acetylide ion. The acetylide ion acts as a nucleophile and attacks the methyl group to form propyne and a lithium iodide side product. \( \text{H-C} \equiv \text{C-Li}^+ + \text{CH}_3\text{I} \rightarrow \text{Propyne} + \text{LiI} \)

To synthesize propyne from acetylene, follow these steps: 1. Treat acetylene with n-butyllithium in an ether solvent to form the lithium acetylide ion. 2. Add iodomethane to the lithium acetylide ion solution, which results in the formation of propyne and lithium iodide as a side product.