6.18 THE E1 REACTION
- Treating tert-butyl chloride with 80% aqueous ethanol at 25°C gives substitution
products in 83% yield and an elimination product in 17% yield.
H 3 CC Cl
CH 3
CH 3
80% C 2 H 5 OH
20% H 2 O
25 oC
H 3 CC OH OCH 2 CH 3
CH 3
CH 3
+ H 3 CC
CH 3
CH 3
tert-Butyl alcohol tert-Butyl ethyl ether
C
CH 3
CH 3
H 2 C
(83%)
2-Methylpropene(17%)
1) The initial step for reactions is the formation of a tert-butyl cation.
H 3 CC Cl − + Cl −
CH 3
CH 3
H 3 CC
CH 3
CH 3
(solvated) (solvated)
slow +
2) Whether substitution or elimination takes place depends on the next step (the fast
step).
i) The SN1 reaction:
H 3 CC
CH 3
CH 3
HO Sol O
Sol
H
O Sol
HOSol
HOSol
H
+
(Sol = H− or CH 3 CH 2 −)
fast H 3 CC +
CH 3
CH 3
H 3 CC
CH 3
CH 3
+ + reactionSN^1
ii) The E1 reaction:
