CHEM 140A Lecture Notes - Lecture 19: Williamson Ether Synthesis, Alcohol, Methanesulfonyl Chloride
6 Apr 2018
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Key point, mechanisms are different depending on primary vs secondary/tertiary, any secondary/tertiary alcohol is protonated and leaves as water. From mscl, py or tscl, py: how to make ether, alkoxide: or- Sn2 primary (table 7-4: but just treating a primary alcohol with acid can create ethers: williamson ether. Synthesis: takes high temps: show , either or if no additional information, but high temp favors alkene, also works for secondary. If carbon chains on either ends of ether (unsymmetrical ether), then don"t use alcohol, use alkoxide: exception: t-butanol. In order to use lialh4 on alcohols to create ethers, need to disguise the alcohol part with t-butanol to prevent it from reacting with alcohol. Special case with neopentyl: ring-strained ether, h2o and h+ (acidic, more substituted carbon in ring is more positively charged (even though more hindered). So shaded o attacks that carbon with the me.
