RDP Lecture on ether, preparation, Properties and Uses

Introduction
Classification
Nomenclature
Methods of Preparation
Properties
Uses
Assignments

1. Ether Lecture by: Ram Darash Pandey Assistant Professor Amrit Campus, Thamel Kathmandu St. Xavier’s College, Maitighar

2. Ether can be defined as, a monoalkyl derivative of alcohol. a dialkyl derivative of Water. The formula is R — O — R ¢ where R and R ¢ are alkyl or aryl. The general formula is C n H 2n+2 O Introduction

3. Classification Ether can be classified as, Simple or symmetrical ether: R-O-R ( When two R groups are identical).Example: Mixed or unsymmetrical: R-O-R’ ( When two R groups are different). Example: Ether can be classified in other ways as, Aliphatic ether: Aromatic ether: Aryl alkyl ether:

4. Cyclic ether Heterocyclic: Oxygen is part of the ring. Epoxides ( oxiranes ) Oxetanes Furans ( Oxolanes ) Pyrans ( Oxanes ) Dioxanes

5. Crown Ether Complexes Crown ethers can complex metal cations inside the ring. The size of the cation will determine the size of the ring needed. Complexation by crown ethers often allows polar inorganic salts to dissolve in nonpolar organic solvents.

6. Structure and Polarity Oxygen is sp 3 hybridized. Bent molecular geometry. C — O — C angles is 110 °. Polar C—O bonds. Dipole moment of 1.3 D.

7. Nomenclature Common Names of Ethers Name the two alkyl groups attached to the oxygen and add the word ether . Name the groups in alphabetical order Symmetrical: Use dialkyl or just alkyl. C H 3 C H 2 O C H 2 C H 3 C H 3 O C C H 3 C H 3 C H 3 diethyl ether or ethyl ether t -butyl methyl ether or methyl t -butyl ether

8. IUPAC Names The more complex alkyl group is the alkane name. The small group (with the oxygen) becomes an “alkoxy” group. C H 3 O C C H 3 C H 3 C H 3 O C H 3 2-methyl-2-methoxypropane Methoxycyclohexane

9. Isomerism Ethers can show : Chain Isomerism Position Isomerism Functional Isomerism with alcohol Metamerism

10. Methods of Preparation 1. From Alcohol:

11. 2. Williamson’s Synthesis of Ether:

12. Williamson synthesis of ether is a) SN1 reaction b) SN2 reaction c) E2 reaction d) E1 reaction

13. Which of the following has highest boiling point ? n-butyl alcohol b) Diethyl ether c) 1-methoxypropane d) 2-methoxy propane

14. Chemical Properties 1. Action of air ( Oxidation reaction)

15. 2. Formation of oxonium salt:

16. 3. Formation of coordinated complex:

17. 4. Cleavage reactions:

18. 5. Reaction with Cl 2 :

19. Assignment

20. Uses of Ether