Unit - NCERT

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After studying this Unit, you will beable to name alcohols, phenols andethers according to the IUPACsystem of nomenclature; discuss the reactions involved inthe preparation of alcohols fromalkenes, aldehydes, ketones andcarboxylic acids; discuss the reactions involved inthe preparation of phenols fromhaloarenes, benzene sulphonicacids, diazonium salts andcumene; discuss the reactions forpreparation of ethers from(i) alcohols and (ii) alkyl halidesand sodium alkoxides/aryloxides; correlate physical properties ofalcohols, phenols and ethers withtheir structures; discuss chemical reactions of thethree classes of compounds onthe basis of their , phenols and ethers are the basic compounds for theformation of detergents, antiseptics and fragrances, ,,,,, PhenolsPhenolsPhenolsPhenolsPhenolsandan dandandand EEEEEthertherthertherthersssssAlcoholsAl coholsAlcoholsAlcoholsAlcohols,,,,, PhenolsPhenolsPhenolsPhenolsPhenolsandan dandandand EEEEEthertherthertherthersssssYou have learnt that substitution of one or morehydrogen atom(s) from a hydrocarbon by another at

unsymmetrical alkenes, the addition reaction takes place in accordance with Markovnikov’s rule (Unit 13, Class XI). Mechanism The mechanism of the reaction involves the following three steps: Step 1: Protonation of alkene to form carbocation by electrophilic attack of H3O +. H2O + H + +→ H 3O Step 2: Nucleophilic attack of water on carbocation.

  Reactions, Electrophilic