Question

26 multiple answer 2 points which of the following mechanisms (s_n1, s_n2, e1, e2) feature(s) a carbocation intermediate? e1 s_n1 e2 s_n2 previous

Explanation:

• For \( S_N1 \):
• The \( S_N1 \) (nucleophilic substitution unimolecular) mechanism has two - step. In the first step, the leaving group departs, forming a carbocation intermediate. Then the nucleophile attacks the carbocation.
• For E1:
• The E1 (elimination unimolecular) mechanism also has two - step. First, the leaving group leaves to generate a carbocation intermediate. Then a base abstracts a proton from an adjacent carbon, and the electrons form a double bond.
• For \( S_N2 \):
• The \( S_N2 \) (nucleophilic substitution bimolecular) mechanism is a concerted process. The nucleophile attacks and the leaving group departs simultaneously. There is no carbocation intermediate.
• For E2:
• The E2 (elimination bimolecular) mechanism is a concerted process. The base abstracts a proton, and the leaving group departs simultaneously. There is no carbocation intermediate.

Answer:

A. E1, B. \( S_N1 \)