Advices For Studying Organic Chemistry

10.11D ANTIOXIDANTS

1. Autoxidation is inhibited by antioxidants.
   
   
   1. Antioxidants can rapidly “trap” peroxyl radicals by reacting with them to give
      stabilized radicals that do not continue the chain.
   
   
   
   


2. Vitamin E (α-tocopherol) is capable of acting as a radical trap which may inhibit
   radical reactions that could cause cell damage.


3. Vitamin C is also an antioxidant (supplements over 500 mg per day may have
   prooxidant effect).


4. BHT is added to foods to prevent autoxidation.

H 3 C O

HO

CH 3

CH 3

CH 3

Vitamin E (α-tocophero)

(CH 3 ) 3 C

OH

C(CH 3 ) 3

CH 3

O

HO OH

O CH CH 2 OH

OH

BHT Vitamin C

(butylated hydroxytoluene)

10.11E OZONE DEPLETION AND CHLOROFLUOROCARBONS (CFCs):

1. In the stratosphere at altitudes of about 25 km, very high energy UV light converts
   diatomic oxygen (O 2 ) into ozone (O 3 ).

Step 1 O 2 + hν O + O