From Haloalkanes:-

When HaloAlkanes (alkyl halides) are heated with aqueous sodium or Potassium Hydroxide, they forms alcohols

Haloalkanes

From Alkenes:-

Alcohols can be produced from Alkenes by their Hydration, by passing alkenes through concentrated H2SO4 and then hydrolysis with boiling water gives alcohols.

Mechanism: – it involves following steps

(i) Electrophilic attack by hydroxyl union on alkenes gives a carbocation intermediate :-

Electrophilic attack by hydroxyl

 

(ii) Nucleophilic attack by water on 20 carbocation

Nucleophilic attack by water

 

(iii) Deprotonation or loss of proton to form alcohol
Deprotonation or loss of proton to form alcohol

 

From Hydroboration – oxidation :- B2H6 (Diborane) if C- deficient molecule it acts as an electrophilic and react with alkenes to form trialkylborates  which on subsequent oxidation with alkaline H2O2 gives alcohols
preparation of Alcohols from Hydroboration oxidation

From Carbonyl Compounds:-

  • By reduction of aldehyde and ketones.

R – CHO reacting with H2/Ni or Na/ C2H5OH giving R – CH2 OH.

Aldehyde or LiAlH4 or NaBH4  1o alcohol

By reduction of aldehyde and ketones

  • By reduction of Carboxylic acids and esters:-

By reduction of Carboxylic acids and esters

 

From Oxy-Mercuration DeMercuration of alkene:-

By simple addition of water to alkene reagent used in this process is mercuric acetate

From Oxy-Mercuration DeMercuration of alkene

 

Form Grignard Reagents:-

Regents are alkyl or aryl magnesium halides (R – MgX)

Process:-

From Oxy-Mercuration DeMercuration of alkene

 

Basic magnesium halide

 

Example : From aldehyde gives alcohol

Basic magnesium halide

 

Hydrolysis of ester

Hydrolysis of ester

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Class 12 Chem Alcohols, Phenols and Ethers All Topics Notes Class 12 Chemistry All Chapter Notes

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