Alkanes, Alkenes, Alkynes, Alkyl Halides, Alicyclic Hydrocarbons, Alcohols, Ethers and Epoxides, Aldehydes and Ketones, Carboxylic Acids and their Functional Derivatives

1. Epoxides
By Priyanka

2. Epoxides
• Epoxides are the cylclic ethers in
which ethereal oxygen is linked
with two adjacent carbon to
form three membered ring. i.e.
oxiran (oxirane) ring. Epoxy
compound contain oxirane ring.
Oxiran compounds are also
referred to as cyclic ethers or
alkene oxides.Epoxy ethane or
ethylene oxide (oxiran) is the
most important member of this
group.

3. Method of preparation epoxide
• Epoxides may, in general, be
prepared by epoxidation of
alkenes with peroxy acids.
Perbenzoic acid C6H5COO2H,
monoperphthalic acid,
HOOCC6H4COO2H and P-nitro
benzoic acid have been used.

4. Method of preparation epoxide
• Ethylene oxide may be
obtained:
i) By Reaction of
Chlorohydrin with base:
• By oxidation of ethylene
with oxygen in the
presence of silver catalyst.

5. Method of preparation epoxide
• First, an alkene is converted to a chlorohydrin, and second, the
chlorohydrin is treated with a base to eliminate hydrochloric acid,
giving the epoxide; this is the method used to make propylene oxide.

6. Properties of epoxides
Ethylene oxide is toxic, flammable gas having b.p
10.7oC.generally epoxides are reactive
compound, this is because to release their strain
they have the tendency to open their ring. These
oxygen atoms combine with the reactive
hydrogen atom of various compounds to form
hydroxylgroup.

7. Reaction with Grignard Reagent
• Ethylene oxide reacts with Grignard Reagent to give addition product
which on hydrolysis yield primary alcohol.

8. Epoxides are oxidized with dimethyl sulphoxide to
α-hydroxy ketones.

9. Properties of epoxides
• Epoxides are easily opened,
under acidic or basic conditions,
to give a variety of products with
useful functional groups. For
example, the acid- or base-
catalyzed hydrolysis of propylene
oxide gives propylene glycol.

10. Uses of Epoxides
• Epoxides can be used to assemble polymers known as epoxies, which
are excellent adhesives and useful surface coatings. The most
common epoxy resin is formed from the reaction of epichlorohydrin
with bisphenol A.