[Gameofketones]

During the electrophilic substitution in phenol at Ortho and para positions, one of the structure in each satisfies octet rule. One of the structure is attached below. Can anyone please explain how it satisfies octet rule ?

[Babcock_Hall]

It is a forum rule (see Red Link above) that you must show your attempt at solving a problem before we can help you.  What would constitute a violation of the octet rule in your judgment?

[Gameofketones]

In the structure 1b Oxygen has a positive charge. So how can it satisfy octet rule when it has lost 1 e- ?

[mjc123]

It hasn't lost an electron. It has shared a pair of electrons with (what I presume is) the carbocation in 1a. Those electrons still count in its valence tally.

[Gameofketones]

So the carbocation doesn't satisfy octet rule because Oxygen is the donor and hence it cannot be counted in carbon's valency?

[Babcock_Hall]

Shared electrons still count.

[mjc123]

The carbocation 1a does not satisfy the octet rule because the +ve carbon has only 6 valence electrons (it has an empty p orbital). In 1b, the oxygen shares one of its lone pairs with the carbon to form a pi bond. This pair therefore counts for both O and C, and both satisfy the octet rule. The formal positive charge sits on O.