4. Addition of water( Hydration):- Acid catalyzed addition of water
CH3 CH CH + H O
2 2
65-70 % H2SO4
CH3 CH CH3 OH
CH3 |
C
CH2
|
H2O / H |
CH 3
CH3
|
C CH
3 OH
|
CH3 |
|
|
|
|
Oxidation:- Combustion:- CO2 + H2O
Hydroboration – oxidation:- Alkanes react with diborane to form trialkyl boranes which on oxidation with alkaline H2O2 give alcohols.
3CH2 = CH2 |
BH3 CH
3
CH
2 3 B
Triethylborane
|
H2O2 / OH- |
3CH3CH2OH Ethyl alcohol |
Oxymercuration – demercuration:-
Hg( OAC) 2
Hg OAC NaBH4
H2C CH2
CH 2 CH 2
CH3CH2OH + Hg THF, H2O OH
OH
Oxidation with potassium permanganate:- 2KMnO 4 + H 2 O 2KOH + 2MnO 2 + 3 [ O ]
3 C C + H2O + O Cold 3 C C
From KMnO4
OH OH
( pink Colour)( Colourless) This reaction is also called Hydroxylation Cis product I. e. cis-diol is obtained.
Noted:- The alkaline potassium permanganate solution is known as Baeyer’ s reagent. It has bright pink colour. It oxidizes alkenes to glycols which is colourless. This reaction is used as a test for the presence of double bond in a molecule. This is also known as Baeyer test.
( i) Alk. KMnO 4 CH 3 CH CH 2 CH COOH + CO
2
+ H O
3 2
( ii) H +