Alcohol Phenols And Ethers

Identify $[\mathrm{X}]$ used in the given reaction.

$[\mathrm{X}]+$ Copper $/ 573 \mathrm{~K} \rightarrow[\mathrm{Y}]$

$[\mathrm{Y}] \xrightarrow[\text { (ii) } \mathrm{H}_2 \mathrm{O} / \mathrm{H}^{+}]{\text {(i) } \mathrm{CH}_3 \mathrm{MgBr}}$ Tert.butyl alcohol. (major product)