Question

Chap 8 - Addition Reactions to Alkenes A reaction is regioselective when two or more constitutional isomers might be expected to reasonably form as products, but one of them predominates. tert-butyl chloride 100 iso-butyl chloride There are degrees of regioselectivity ranging from no regioselectivity to completely regioselective. The top example is a completely regioselective reaction. (reason: 3° carbocation vs 1° carbocation). The greater the differences in the AG" value between two different carbocation pathways, the more regioselective the reaction will be. Example: Which alkene will lead to a more regioselective reaction with HCI? VS.

Answer 1

Reaction 1 # Carê secondary carbocation Reaction 2 + HCl, el , Tertiary carbocation In case of alkene in reaction 1, it forms a 2 secondary carbocation while in reaction 2, the alkene produces a tertiary carbocation which is more stable than secondary carbocation. Therefore, Alkene B will be more regioselective