Which one of the following carbocations is NOT expected to rearrange?

Question

Vimal Swarnkar · Accepted Answer

(d) 1-Methylcyclohexyl cation. Rearrangement happens only if a more stable cation can form. (a) 1° cyclohexylmethyl → shifts/ring-expands. (b) 2° next to a 3° C–H → hydride shift to 3°. (c) allylic, delocalised. (d) 1-methylcyclohexyl is tertiary; no shift gives a more stable ion → does not rearrange → (d).

Answer

(a) Cyclohexylmethyl cation

Answer

(b) 2-Methylcyclohexyl cation

Answer

(c) 2-Methylenecyclohexyl (allylic) cation

Geo-Scientist Prelims 2020 Chemistry Q86: Which one of the following carbocations is NOT expected to rearrange?

QuestionOrganic / carbocation rearrangement