C 6​ H 5​ MgBr+CH 3​ CH 2​ CH 2​ C≡CH→

The reaction you've written is a Grignard reaction. The Grignard reagent (C6H5MgBr) reacts with the alkyne (CH3CH2CH2C≡CH) to form a new carbon-carbon bond. Here's the step-by-step process:

1. Formation of Grignard Reagent: The Grignard reagent is formed by the reaction of an alkyl or aryl halide with magnesium metal in dry ether. In your case, the Grignard reagent is already provided (C6H5MgBr).

2. Nucleophilic Addition: The Grignard reagent acts as a strong nucleophile and attacks the electrophilic carbon in the triple bond of the alkyne. This forms a new carbon-carbon bond and generates a magnesium bromide salt.

3. Protonation: The final step is the protonation of the negatively charged carbon (from the magnesium bromide salt) by a proton source, usually a dilute acid, to form the final product.

The exact product of your reaction would depend on the specific conditions (like the presence of any other reagents, temperature, etc.). But generally, a Grignard reaction with an alkyne would result in the formation of a new carbon-carbon bond.