Question

In the given compounds, arrow indicate direction of inductive effect. Choose the compound in which direction of inductive effect shown is incorrect.

• A.
• B.
• C.
• D.

Answer 1

The correct option is A

Case (a) has the incorrect direction of I - effect because NO is Electron withdrawing group that means it will withdraw electron pairs towards itself.

Case (b) has the correct direction of I-effect because -CN is electron withdrawing group.

Case (c) has the correct direction of I-effect because -COO is electron withdrawing group.

Case (d) has the correct direction of I-effect because -MgBr is electron donating group. Whether something is electron releasing or electron withdrawing depends on its environment. An alkyl group is slightly electron releasing in some hydrocarbon systems, as when it is attached to a phenyl group. But that does not carry over to all compounds carrying an alkyl group. In carbon–magnesium bond, the carbon atom has a partial negative charge and magnesium has a partial positive charge as metals are always electropositive, that's why here MgBr acts as an electron donating group.