Preparation of Alcohols Catalytic hydration and grignard reagents reaction

 Preparation of Alcohol 

1. By Catalytic Hydration 

• Alkenes react with water in the presence of acid as a catalyst to form alcohol. 
• In case of unsymmetrical the addition of OH and H is takes by Markovnikov rule. 

Reaction Mechanism 

2. By Hydroboration Oxidation

When alkenes react with diborane to give trialkyl boranes as addition production which further oxidise by Catalyst to give alcohol.   

• The addition of diborane on alkene is takes place by antimarkovnikov rule. 
• In this reaction excellent amount of alcohol is produced. 

2. From Carbonyl Compounds  

   i)  By Reduction of Aldehyde and Ketones  

By reduction of Aldehyde and Ketones, Aldehyde convert into primary alcohol and ketone convert into secondary alcohol. 

ii) Reduction by Sodium Borohydride  

iii) Reduction by Lithium Aluminium Hydride

 

iv) Reduction of Carboxylic Acid and Esters 

Reduction of Carboxylic Acid by strong reducing agent like LiAlH4 to form alcohol 1° alcohol. 

 

Aldehyde can also be prepared by forming ester which on further reduction by Catalytic hydrogenation method gives alcohol. 

3. From Grignard Reagent  

Aldehyde can Ketones are prepared by reaction of Aldehyde and Ketones with grignard reagent. 

We obtain primary alcohol when methanal is treated with grignard reagent and 2° alcohol when all other Aldehydes are treated with Grignard Reagent. 

We obtain 3° Alcohol when ketones are treated with Grignard Reagent. 

Mechanism