Alkynes are hydrocarbons containing a single triple $\text{C} \equiv \text{C}$ bond. As with alkenes, alkynes undergo addition reactions, and this can produce a saturated compound. For instance, ethyne, $\text{H}-\text{C} \equiv \text{C}-\text{H}$, reacts with excess hydrogen to give ethane. Propyne, $\text{C}_3\text{H}_4$, reacts with excess hydrogen bromide by addition in two steps. Markovnikov’s rule is used for the addition of HBr in each step. Which is the main product formed when propyne reacts with excess hydrogen bromide?
- A$\text{CH}_2\text{BrCH}_2\text{CH}_2\text{Br}$
- B$\text{CH}_3\text{CH}_2\text{CHBr}_2$
- C$\text{CH}_3\text{CHBrCH}_2\text{Br}$
- D$\text{CH}_3\text{CBr}_2\text{CH}_3$