When 2−bromo−3,3−dimethylbutane is treated with K⁺ −OC(CH₃)₃, a single product T having molecular formula C₆H₁₂. When 3,3−dimethyl−2−butanol is treated with H₂SO₄, the major product U has the same molecular formula. Given the following ¹H NMR data, what are the structures of T and U?