The number of hyperconjugation structures involved to stabilize carbocation formed in the reaction of 2-methylcyclohexan-1-ol with HBr is _______

When 2-methylcyclohexan-1-ol reacts with HBr, the OH group is first protonated to form a good leaving group ($$H_2O$$), which departs to give a secondary carbocation at C1.

Now, this secondary carbocation at C1 undergoes a 1,2-hydride shift from C2 to form a more stable tertiary carbocation at C2 (the carbon bearing the methyl group).

We have the tertiary carbocation at C2 bonded to:

- C1 (which now has 2 hydrogen atoms since OH left as water)

- C3 (which has 2 hydrogen atoms)

- $$CH_3$$ group (which has 3 hydrogen atoms)

Each $$\alpha$$-hydrogen can participate in hyperconjugation with the empty p-orbital of the carbocation.

So, total number of hyperconjugating hydrogens = 2 + 2 + 3 = 7.

Hence, the number of hyperconjugation structures is $$7$$.