434 CHAPTER 11 Elimination Reactions of Alkyl Halides • Competition Between Substitution and EliminationProblems
- Give the major product obtained when each of the following alkyl halides undergoes an E2 reaction:
- Give the major product obtained when the alkyl halides in Problem 29 undergo an E1 reaction.
- a. Indicate how each of the following factors affects an E1 reaction:
- the structure of the alkyl halide 3. the concentration of the base
- the strength of the base 4. the solvent
b. Indicate how each of the same factors affects an E2 reaction.
- Dr. Don T. Doit wanted to synthesize the anesthetic 2-ethoxy-2-methylpropane. He used ethoxide ion and 2-chloro-2-methyl-
propane for his synthesis and ended up with very little ether. What was the predominant product of his synthesis? What reagents
should he have used? - Which reactant in each of the following pairs will undergo an elimination reaction more rapidly? Explain your choice.
a. b.- For each of the following reactions, give the elimination products; if the products can exist as stereoisomers, indicate which
isomers are obtained.
a.
b.
c.
d.
e.
f. - Indicate which of the compounds in each pair will give a higher substitution/elimination ratio when it reacts with isopropyl
bromide:
a. ethoxide ion or tert-butoxide ion c. or
b. -OCNor d.-SCN CH 3 S-or CH 3 O-
Cl- Br-3-bromo-3-methylpentane+H 2 O3-bromo-3-methylpentane+high concentration of HO-trans-1-chloro-2-methylcyclohexane+CH 3 OHtrans-1-chloro-2-methylcyclohexane+high concentration of CH 3 O-(R)-2-bromohexane+H 2 O(R)-2-bromohexane+high concentration of HO-CH 3CH 3 O−
CH 3 OHCH 3HHH
BrCH 3 O−
CH 3 OHCH 3HHBr
HCH 3(CH 3 ) 3 CClHO−
H 2 O(CH 3 ) 3 CIHO−
H 2 OClCH 3 CHCH 2 CH 3Bra. CH 3 CHCH 2 CH 3d.e.f.g.b.Clc. CH 3 CHCH 2 CH 2 CH 3ClCH 2 ClCH 3ClCH 3ClBRUI11-400_436r3 26-03-2003 10:20 AM Page 434