Nu:− + C OH+ H SN^2 Nu C OH
Protonated alcohol
+ H
2) Alcohols are nucleophiles ⇒ they can react with protonated alcohols to afford
ethers.
+ C HO+ H SN^2 O C OH
Protonated alcohol
R O + H
H
R
H
+
Protonatedether
3) At a high enough temperature, and in the absence of a good nucleophile,
protonated alcohols are capable of undergoing E1 or E2 reactions.
11.9 ALCOHOLS AS ACIDS
- Alcohols have acidities similar to that of water.
- Methanol is a slightly stronger acid than water but most alcohols are somewhat
weaker acids.
Table 11.3 pKa Values for Some Weak Acids
Acid pKa
CH 3 OH 15.5
H 2 O 15.74
CH 3 CH 2 OH 15.9
(CH 3 ) 3 COH 18.0
2) The lesser acidity of sterically hindered alcohols such as tert-butyl alcohol arises
from solvation effects.
i) With unhindered alcohols, water molecules are able to surround and solvate the
