Question #44625

Consider the enantiomerically pure alkyl halide, (S)-2-bromo-3-methylbutane (\textbf{A}). It undergoes three distinct parallel reaction sequences:

Reaction I: \textbf{A} is treated with $\ce{NaCN}$ in anhydrous DMSO to yield major product \textbf{D}.

Reaction II: \textbf{A} is treated with potassium tert-butoxide ($\ce{t-BuOK}$) in tert-butanol at $70^\circ\text{C}$ to yield major product \textbf{B}. \textbf{B} is then subjected to hydroboration-oxidation ($\ce{B2H6/THF}$ followed by $\ce{H2O2/NaOH}$) to yield \textbf{E}.

Reaction III: \textbf{A} is treated with sodium ethoxide ($\ce{NaOEt}$) in ethanol at $70^\circ\text{C}$ to yield major product \textbf{C}. \textbf{C} is then subjected to oxymercuration-demercuration ($\ce{Hg(OAc)2/H2O}$ followed by $\ce{NaBH4}$) to yield \textbf{F}.

Identify the correct IUPAC names and stereochemistry for \textbf{D}, \textbf{E}, and \textbf{F}.