Alkyl groups in carbocations

The carbocations that are formed to generate these two products are shown on the left. You will recall that alkyl groups can exert a positive inductive effect (see p. 59), i.e. they can push electrons towards the positively charged carbon atom in the carbocation and so stabilise it. Therefore carbocation A will be more stable than carbocation B because it has two alkyl groups directly attached to the positively charged carbon atom, whereas there is only one alkyl group in carbocation B. 

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