Alcohols, Phenols and Ethers: PREPARATION OF ALCOHOLS:Hydrolysis of alkyl halides;Hydrolysis of alkyl halides in presence of a base like KOH or NaOH gives alcohols. This reaction is a nucleophilic substitution reaction. Hydration of alkenes:Alkenes upon hydration in presence of dilute H2SO4 gives alcohols. In primary alcohols only ethyl alcohol can be prepared by this method. Since this method generally gives 20 and 30 alcohols. This is an acid catalysed hydration. In case of unsymmetrical alkenes addition of H-OH takes place according to Markovnikov's rule. Mechanism : Involves 3 steps. Step –1 is protonation of alkene to form carbocation by the attack of H3O+ electrophile Step –2 is Nucleophilic attack of water on carbocation Step– 3 is de protonation to form an alcohol.

Hydroboration oxidation of alkenes : Diborane B2H6 react with alkene to form trialkyl borane as an addition product no carbo cation intermeadiate which on oxidation with hydrogen peroxide in presence of Na OH aq gives alcohol. The alcohol formed looks like the addition of water to alkene according to anti-Markovnikov’s rule.

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