Alcohol Phenols And Ethers

An alcohol $X\left(\mathrm{C}_4 \mathrm{H}_{10} \mathrm{O}\right)$ on dehydration gave alkene $\left(\mathrm{C}_4 \mathrm{H}_8\right)$ as major product, which on bromination followed by treatment with $Y$ gave alkyne $\mathrm{C}_4 \mathrm{H}_6$. Alkyne $\mathrm{C}_4 \mathrm{H}_6$, does not react with sodium metal. What are $X$ and $Y$ ?