1. Ethers and Thioethers 2

2. Bond angles at oxygen are sensitive to steric effectsH H
CH3 H
105°
108.5° O
(CH3)3C O
C(CH3)3
CH3
CH3
112°
132° 9

3. Functional Class IUPAC Names of Ethers
name the groups attached to oxygen in alphabetical order as separate words; "ether" is last word
CH3OCH2 CH3
ethyl methyl ether
CH3CH2OCH2CH2CH2Cl
3-chloropropyl ethyl ether
CH3CH2OCH2 CH3
diethyl ether 3

4. Substitutive IUPAC Names of Ethers
name as alkoxy derivatives of alkanes
CH3OCH2 CH3
methoxyethane
CH3CH2OCH2CH2CH2Cl
1-chloro-3-ethoxypropane
CH3CH2OCH2 CH3
ethoxyethane 3

5. An oxygen atom affects geometry in much the same way as a CH2 group
most stable conformation of diethyl ether resembles pentane 10

6. An oxygen atom affects geometry in much the same way as a CH2 group
most stable conformation of tetrahydropyran resembles cyclohexane 10

7. PREPARATION CH3CH2CH2CH2ONa + CH3CH2I CH3CH2CH2CH2OCH2CH3 + NaI (71%)25

8. Ethers resemble alkanes more than alcohols with respect to boiling point
Intermolecular hydrogen bonding possible in alcohols; not possible in alkanes or ethers.
36°C
35°C O
117°C OH 12

9. solubility in water (g/100 mL)
Ethers resemble alcohols more than alkanes with respect to solubility in water
solubility in water (g/100 mL)
very small
7.5
Hydrogen bonding to water possible for ethers and alcohols; not possible for alkanes. O 9 OH 12

10. Summary of reactions of ethers
. Ethers are relatively unreactive.
Their low level of reactivity is one reason why ethers are often used as solvents in chemical reactions.
Ethers oxidize in air to form explosive hydroperoxides and peroxides. 27

11. REACTIONS HBr CH3CHCH2CH3 CH3Br + heat OCH3 Br (81%) CH3OCH3 CH3O+CH3
HHH H+
CH3O+CH3
CH3OCH3 H 31

12. Substitutive IUPAC Names of Sulfides
name as alkylthio derivatives of alkanes
CH3SCH2 CH3
methylthioethane
SCH3
(methylthio)cyclopentane
CH3CH2SCH2 CH3
ethylthioethane 3

13. Functional Class IUPAC Names of Sulfides
analogous to ethers, but replace “ether” as last word in the name by “sulfide.”
CH3SCH2 CH3
ethyl methyl sulfide
SCH3
cyclopentyl methyl sulfide
CH3CH2SCH2 CH3
diethyl sulfide 3

14. prepared by nucleophilic substitution (SN2)
Preparation of RSR'
prepared by nucleophilic substitution (SN2) – ••
• • •• R S R' R S + R' X
NaSCH3
CH3CHCH
CH2 Cl
CH3CHCH
CH2
SCH3
methanol

15. Oxidation of RSR' •• R S R' O
• • – + O
• • •• – ++ •• R S R' R S R' O
• • •• –
sulfide
sulfoxide
sulfone
either the sulfoxide or the sulfone can be isolated depending on the oxidizing agent and reaction conditions

16. Sulfides can act as nucleophiles+ •• •• R S +
R" X R S
R" X–
• • R' R'
product is a sulfonium salt