1 Which of the following SN2 reactions is the slowest B CH3C

1. Which of the following SN2 reactions is the slowest? B) CH3C1l2CH2C1+ HO- CH3C1 12C11201 1 + Cl- C) CH3CH2CH2HO - CH3CH2CH2OH +I 2. In each of the pairs below, which is the best nucleophile in alcoholic solvents? CHsS or CH:o iii (CH3)2NH or (CH3)3N iv) SCN or OCN ii) C or F i. CH3S-, F, (CH3)2NH, SCN- ii. CHsS-, F-, (CH3)2NH, SCN- iii. CH3S-, F, (CH3)2NH, OCN- D) CH3S-, Cl-, (CH3)2NH, SCN E) CH3S, F, (CH3)3N, SCN-

Solution

1. Option D, since F is not good leaving group. Hence slowest reaction.

2. I. CH3S-, since Sulfur is less electronegative than oxygen

II. Cl-, same reason.

III. (CH3)3N

IV. SCN-