Compound $\text{A}$ of molecular formula ${\text{C}}_{\text{4}}{\text{H}}_{\text{10}}\text{O}$ on treatment with Lucas reagent at room temperature gives compound $\text{B}\text{.}$ When compound $\text{B}$ is heated with alcoholic $\text{KOH,}$ it gives isobutene. Compound $\text{A}$ and $\text{B}$ are respectively