Advices For Studying Organic Chemistry

3) PCC and PDC are cancer suspect agents and must be dealt with care.

4. One reason for the success of oxidation with PCC is that the oxidation can be
   carried out in a solvent such as CH 2 Cl 2 , in which PCC is soluble.

1. Aldehydes themselves are not nearly so easily oxidized as are the aldehyde
   hydrates, RCH(OH) 2 , that form when aldehydes are dissolved in water, the usual
   medium for oxidation by PCC.
   RCHO + H 2 O RCH(OH) 2

12.4B OXIDATION OF PRIMARY ALCOHOLS TO CARBOXYLIC ACIDS:

RCH 2 OH → RCO 2 H

1. 1° alcohols can be oxidized to carboxylic acids by potassium permanganate.
   
   
   1. The reaction is usually carried out in basic aqueous solution from which MnO 2
      precipitates as the oxidation takes place.
   
   
   2. After the oxidation is complete, filtration allows removal of the MnO 2 and
      acidification of the filtrate gives the carboxylic acid.
   
   
   
   

R CH 2 OH

H 3 O+

CO 2 H

+ KMnO OH−

4 R K+ +

heat

H CO^2 −^

2 O

MnO 2

R

12.4C OXIDATION OF SECONDARY ALCOHOLS TO KETONES

1. 2° alcohols can be oxidized to ketones.
   
   
   1. The reaction usually stop at the ketone stage because further oxidation requires
      the breaking of a C–C bond.
   
   
   
   

R CH

OH

R C

O
R' [O] R'
2° Alcohol Ketone