Substitution Reactions — Prelims Questions

Which of the following alkyl halides would be most reactive towards an S$_N$1 reaction?

Which of the following conditions would favor an S$_N$2 reaction for a secondary alkyl halide?

When (R)-2-bromobutane reacts with sodium hydroxide in acetone, what is the major product and its stereochemistry?

Which of the following haloarenes would be most reactive towards nucleophilic aromatic substitution (S$_N$Ar)?

Which of the following is the best leaving group in a nucleophilic substitution reaction?

Which of the following solvents would be most suitable for an S$_N$2 reaction?