Topics: Alcohol, Redox, Oxygen Pages: 5 (575 words) Published: September 14, 2011
Hydroxyl compounds
A. Classification:
1. alkanol: primary alcohol (1( alkanol)butan-1-ol

secondary alcohol (2( alkanol) butan-2-ol

tertiary alcohol (3( alkanol)2-methylbutan-2-ol

2. phenol

Classify by number of hydoxyl groups per molecule:
1. monohydric alkanol ethanol

2. polyhydric alkanolethane-1,2-diol

B. IUPAC name:
pent-4-en-2-ol3-bromocyclohexanol but-3-yn-1-ol
hex-2-ene-1,6-diol 2-methylphenol1,4-dihydroxybenzene o-methylphenol p-dihydroxybenzene

C. Preparation:
Industrial process:
1. Fermentation of carbohydrates:
2. Hydration of alkene:
3. Formation of methanol:
Laboratory method:
1. Nucleophilic substitution:
2. Reduction of carbonyl compounds
a. By lithium tetrahydrioaluminate LiAlH4:
Li AlH4 in ether is a strong reducing agent which can reduce acid, ester, carbonyl group (containing O atom) but not alkene and alkyne. [pic]
b. By hydrogenation:
Hydrogenation can also be used to convert alkene and alkyne to alkane. [pic]
3. Oxidation of alkenes:
Oxidize alkene by strong oxidizing agent, acidified potassium permanganate. [pic]
1. Sulphonation
2. Diazo salt
3. Physical properties of alkanol:
a. Intermolecular H-bond
b. High boiling point, melting point and solubility in water

4. Chemical properties of alkanol:
Principle of reaction:

Breakage of C(O bond to form C+ ion Breakage of O(H bond to form R(O( ion Favour stable carbonium ion favor 1((alkanol or R with electron withdrawing group

a. Intramolecular dehydration (Elimination, alkene formation) By dehrating agent:
Condition: high temperature 180(C, Conc. sulphuric acid, mole ratio of alkanol:acid = 1:1 [pic]
By catalyst:
Condition: Aluminium oxide as catalyst, 350(C
b. Intermolecular dehydration
Condition: high temperature 140(C, Conc. sulphuric acid, mole ratio of alkanol:acid = 2:1 [pic]
c. Halogenation
Lucas Test:
Reagent: zinc chloride + Conc. HCl
Procedure: Mix the Lucas reagent with alkanol; observe the rate of the appearance of the turbidity. (Chloroalkane oil droplets are insoluble in aqueous phase.) Result: Turbidity forms immediately.3( alkanol Turbidity forms slowly (5 minutes).2( alkanol Turbidity does not form.1( alkanol

Other reagents for halogenation:
PX3, PX5, SOCl2
white fumes
d. React with sodium
sodium methoxide, a strong organic alkali Application of sodium alkoxide:
Formation of ether:
Formation of alkene:
e. Esterification (Condensation)
ethyl ethanoate
f. Oxidation
Oxidizing agents: KMnO4/H+/neutral/OH(
Mild oxidizing agent: CuO
Strong oxidizing agent: KMnO4/H+
Different alkanols are refluxed with acidified potassium permanganate: Primary alkanol:
Continue Reading

Please join StudyMode to read the full document

Become a StudyMode Member

Sign Up - It's Free