Question

1. Arrange the following alkyl halide electrophiles with respect to Sn2 reactivity (least reactive → most reactive). Explain D-ci +ci ~ Α 2. Which compound in each of the following pairs will react faster in an SN2 reaction with HO-. Briefly provide your reasoning to support your answer a) CH3Br or CH31 b) CH3CH2l in ethanol or dimethyl sulfoxide c) (CH3)3CCI or CH3CI 3. Each of the following molecules contain two halogens of different kinds. In each case, determine which of the two halogens will be the more reactive in the Sn2 reaction. Explain Br xBr cmBr

Answer 1

7 Aneyl halides reactivity order of sN? is 10 > 207 30 so ooder cal reactivity is- tea Deky na (B) (A) 1) (0) shows high primary alkyl halide réactivity of sn? (10) - cyclopropyl is ce and e. > (20) planas so, due to mechanism is less angle stron SN2. supported by it.

reactive textiary or 30 allegt halide is least towards s.² (ta). Instead it IN mechanimn. Chy Bro or Cty I groups. so it c-thologen In S.? Nudeophile displaces the . bond is weaken then its reactivity towards SN² will be more Thus II has longer and weaker bord thon c-ce. Hence SN? reactivity is more for CH₂ I. cthcthy I in ethanol or crez che I in DM SO thath I in DMSo is more reactive Became SN? substitution is more forourable in polar aprotic solwent. since DMSO is a protic so ctzcth I in Omso has higher reactivity for SNP. or.ct-ce G 3 Che Who Primarry or 10 allyl halides are mare reactive tow arde s2 than 30 alleyl halides.

Primary celagt halide is more recutive in SN? so circled part of ally) halide. is more reactive. Actually 30 alkyt halides haver alkyl group which are electron releasing groups so they in u rnoreone electron density on the carbon bonded with halogen when nucleophile attacks the carbon it finde difficulty in displacing the halogen or any leaving grocep thad's why, seactivity is of order- 10> 207 30 ce m ari Bond length of c-Bi > Gel so c-Br can be brouen easily than.coce so, Br is a good leaving group than ce. Hence. S is more reactive towards c-Br. Reauftulty order - C-17 C-Bryolu