Question

which of the following rearrangements would you not expect the cation below to undergo to any significant extent? h3c ch ch3 ? a) h3c c ch3 h b) ch3 ch2 ch2 c) ch3 ch3 d) none of the above would occur to a significant extent. e) all of the above would be significant.

Answer 1

The student's question is about the expected rearrangement of a secondary carbocation; the least likely rearrangement is to a primary carbocation (option b), as it leads to a less stable carbocation compared to the starting material.

Step-by-step explanation:

The student's question pertains to the expected rearrangements of a carbocation. Carbocations are susceptible to rearrangements to form more stable carbocations.

The stability of carbocations increases in this order: primary (RCH₂) < secondary (R₂CH) < tertiary (R₂C).

Given the cation in question is a secondary carbocation (H3C-CH-CH3), option (a) represents a shift to a tertiary carbocation (H3C-C(CH3)-H), which is more stable and thus likely to occur.

Option (b), on the other hand, represents a shift to a primary carbocation (CH3-CH2-CH2), which is less stable and would not be expected to occur to any significant extent.

Option (c) does not represent a valid carbocation as it has a neutral charge (CH3-CH3). Therefore, the rearrangement described in option (b) would not be expected to occur to any significant extent, making it the correct answer.