Mechanism

Mechanism However, when one of the alkyl group is a tertiary group, the halide formed is a tertiary halide. CH +HI C H OH +CH I O It is because in step of the reaction, the departure of leaving group (HO–CH ) creates a more stable carbocation [(CH ) C + ], and the reaction follows S N mechanism. In case of anisole, methylphenyl oxonium ion, is formed by protonation of ether. The bond between O–CH is weaker than the bond between O–C H because the carbon of phenyl group is sp hybridised and there is a partial double bond character. O H + slow + + CH OH fast + + I – I Therefore the attack by I – ion breaks O–CH bond to form CH I. Phenols do not react further to give halides because the sp hybridised carbon of phenol cannot undergo nucleophilic substitution reaction needed for conversion to the halide. Give the major products that are formed by heating each of the following ethers with HI.