1559.ch11.199-21911/5/0500:51Page213 EQA Solutions o Problems213 50.The of 2-bromopropane 51. CH H H 、CH CHH HH 、CH CH;CH2 CHzCH 2R.3R 25.3R CHS H CH.CH The others would be similar. 52.Referring to problem numbers in Chapter 7: (22b)CH.CH-C(CH3)2>CH2-C(CH.)CH-CH (22e)Comparable amounts These are the only elimination product mixtures in these problems. y substituted alkene isomers form .山d 女凶50. The energy of the E2 transition state for 1-bromopropane is similar to that for 2-bromopropane, because the products are the same (propene). So the E2 rate constants for these two compounds will be similar. However, 1-bromopropane, being primary, will have a faster competing SN2 reaction than will the secondary 2-bromopropane. Overall, it is reasonable to estimate that the actual E2 rate for 1-bromopropane will be intermediate between the rates for bromoethane and 2-bromopropane. 51. These are probably not the most stable conformations because all contain three gauche interactions between alkyl groups or bromine. For the R,R isomer, a better conformation would probably be The others would be similar. 52. Referring to problem numbers in Chapter 7: (22b) CH3CHPC(CH3)2
CH2PC(CH3)CH2CH3 (22c) Comparable amounts (22d) These are the only elimination product mixtures in these problems. 53. Major products are labeled for (a) through (f). Generally, more highly substituted alkene isomers form in highest yields. (g) (h) ~~
~~ ~~ ~~ ~~
C(CH3)3
CH2 CH3 CH3 (CH3)2C
CH2 C(CH3) CH3 CH3 CH2CH3 H Br H 2R,3S CH3 CH3CH2 CH3 H H Br 2S,3R CH3 CH3 CH2CH3 H H Br 2R,3R CH3 CH3 CH2CH3 H H Br 2S,3S CH3 CH3CH2 CH3 H H Br Solutions to Problems • 213 1559T_ch11_199-219 11/5/05 00:51 Page 213