Chapter 16: Ethers, Epoxides and Sulfides
Overview of the Reactions of Epoxides
Reaction type: Nucleophilic Substitution
Summary
Epoxides are much more reactive than simple ethers due to
ring strain
.
Nucleophiles attack the electrophilic C of the
C-O
bond causing it to break, resulting in ring opening.
Opening the ring relieves the ring strain.
The products are typically 2-substituted alcohols.
Epoxides can react with a large range of nucleophiles.
Depending on the reactivity of the nucleophile, there are two possible general scenarios:
Stronger nucleophiles (anionic
e.g.
alkoxides, Grignard reagents
etc
.)
Examples of such nucleophilic systems are :
RMgX
,
RLi
,
RC≡CM
,
LiAlH
4
,
NaBH
4
Weaker nucleophiles (neutral
e.g.
water) can be made to react with epoxides in the presence of acid catalysts.
Examples of such nucleophilic systems are :
H
2
O
,
ROH
,
R-NH
2
©
Dr. Ian Hunt
, Department of Chemistry
