Identify the major final product B of the following reaction sequence.

Step-by-step solution

The reactant is (2S, 3S)-3-deuteriobutan-2-ol . Reaction with SOCl₂ and (CH₃)₃N proceeds via an S_N2 mechanism, causing inversion of configuration at C2 to form (2R, 3S)-2-chloro-3-deuteriobutane (Compound A). Treatment with the strong, bulky base t-BuO^- leads to an E2 elimination, which requires an anti-periplanar arrangement of the leaving group ( Cl ) and the -proton/deuteron. From the most stable conformer of Compound A, anti-elimination of D and Cl yields (E)-2-butene . Alternatively, rotation to a less stabl