Question

17. Which of the following compounds will undergo an SN2 reaction most readily? (CH3)3CBr, (CH3)2CHI, (CH3)2CHCH2CH2CH2Cl, (CH3)2CHCH2CH-CH21 メー 1 E2 18. Provide the structure of the major organic product which results when (S)-2-iodopent treated with NaCN in DMSO.

please explain why

Answer 1

As SN^2 reaction is given more readily by the methyl and primary reactants, then secondary reactants and tertiary reactant do not undergo SN^2 reaction, As in the given, problem, does not participate in reaction after that as primary subtracts reacts more readily than primary, so, the rate at which reaction proceeds is more in (CH_3)_2 CH CH_2 CH_2 CH_2 Cl and (CH_3)_2 CH CH_2 CH_2 CH_2 I than the (CH_3)_2 CH I. Now, among the (CH_3)_2 CH CH_2 CH_2 CH_2 Cl and (CH_3)_2 CH CH_2 CH_2 CH_2 I which reacts more readily {as both are primary} depends on the leaving tendency of leaving group. Group that can easily leave undergo SN^2 reaction more readily. As in this leaving tendency of 'I' is more than the 'Cl', So, (CH_3)_2 CH CH_2 CH_2 CH_2 I readily gives a SN^2 reaction. {because primary & good leaving group} So, answer is (CH_3)_2 CH CH_2 CH_2 CH_2 I. \r\n As we have to react [s]-2