Alcohols, Phenols and Ethers Func�onal Group- OH Suffix to be used - ol Homologous series- Methanol (CH3OH) Ethanol (C2H5OH) Propanol (C3H7OH) Butanol (C4H9OH) Pentanol (C5H11OH) and so on Markownikoff addi�on 1. Boiling Point- * Higher than other organic compounds having equal molecular masses * The boiling point decreases with an increase in branching in alipha�c carbon chains The rela�ve ease of dehydra�on of alcohols follows the following order: Ter�ary > Secondary > Primary * Methanol is a colourless liquid and boils at 337 K * It is highly poisonous in nature * Ethanol is a colourless liquid with boiling point 351 K * It is used as a solvent in paint industry and in the prepara�on of a number of carbon compounds 2. Solubility- * The hydroxyl group in alcohol is involved in the forma�on of intermolecular hydrogen bonding * The solubility of alcohol in water decreases with the increase in the size of the alkyl group Preparatory Methods Physical Proper�es R-OH Chemical Proper�es Reac�ons involving cleavage of O-H bond Some Commercially Important Alcohols Methanol Ethanol Reac�on with Metals Reac�on with phosphorus trihalides Dehydra�on Acidity of Alcohols Acidity of Alcohols Esterifica�on Oxida�on Dehydrogena�on Reac�on with hydrogen halides Alcohols: Weaker acids than water Esterifica�on Reac�ons involving cleavage of C–O bond R-CH=CH2 H2O/H⁺ H2O2 B2H6 H2O2/H2O N2/H2 Na + C2H5OH H2/Pd LiAlH4 i) LiAlH4 ii) H2O i) RMgX ii) H2O/H⁺ An� markownikoff addi�on R-CH=CH2 R-C-Cl RCHO R-COOH R-COO-R’ For the prepara�on of - 10 alcohol – HCHO 20 alcohol – RCHO 30 alcohol – Structure Methanol Cyclohexanol 2-Methylcyclopentanol Dihydric alcohols Monohydric alcohols C2H5OH Part - 1 CH2OH CH2OH Compounds containing C sp 3 -OH bond Compounds containing C sp 2 -OH bond Nomenclature Classifica�on * Primary, secondary and ter�ary alcohols * Allylic alcohols * Benzylic alcohols * Vinylic alcohol Trihydric alcohols CH2OH CHOH CH2OH Alcohol O R-C-R O Prepara�on Proper�es Prepara�on Proper�es H H 142 pm 96 pm 108.9 0 C :O: H H OH OH CH3 CH3 - CH2 - CH2 - O: : H H H H H O O O H H 2R-O-H + 2Na 2R-O-Na+H2 Sodium alkoxide 6 CH3-C-OH + 2Al 2 CH3-C-O Al+3H2 Aluminium tert-butoxide tert-Butyl alcohol CH3 CH3 CH3 CH3 ( ) 3 Secondary Primary Ter�ary R CH2OH > CHOH >> R C- OH R R R R R-O: + H-O:-H R-O-H + :OH : : : : : : Acid Conjugate acid Conjugate base Base R-C-OH + H-O-R R-C-O-R’ + H-O-H Acid Alcohol Ester O O H⁺ ⥮ ROH + HX → R-X + H2O RCH2OH RCHO Cu 573K R-CH-R’ R-C-R’ Cu 573K OH O R-C-OH CH3-C=CH2 Cu 573K CH3 CH3 CH3 RCH2OH R-C=O R-C=O Oxida�on Aldehyde RCH2OH RCHO CrO3 CH3-CH=CH-CH2OH CH3-CH=CH-CHO PCC H OH Carboxylic acid R-CH-R’ R-C-R’ CrO3 OH Sec- alcohol Ketone O 3CH3-CH2-CH2-OH + PCl3 → 3CH3-CH2-CH2-Cl + H3PO3 C2H5OH CH2=CH2+H2O 443K H2SO4 CH3CHCH3 CH3-CH=CH2+H2O 440K 85%H3PO4 OH CH3 CH3 CH3-C-OH CH3-C-CH3+H2O 358K 20%H3PO4 CH2 CO + 2H2 CH3OH 200-300 atm 573-673 K ZnO-Cr2O3 C12H22O11 + H2O C6H12O6 + C6H12O6 Invertase C6H12O6 2C2H5OH + 2CO2 Zymase Glucose Fructose Compound CH3-OH Common name IUPAC name Methyl alcohol Methanol CH3-CH2-CH2-OH CH3-CH2-CH2-CH2-OH HO-H2C-CH2-OH CH3-CH2-CH2-CH2-OH n-Propyl alcohol Propan-1-ol Isopropyl alcohol Propan-2-ol n-Butyl alcohol Butan-1-ol sec-Butyl alcohol Butan-2-ol Isobutyl alcohol 2-Methylpropan-1-ol tert-Butyl alcohol 2-Methylpropan-2-ol CH3-CH-CH3 OH CH2-CH-CH2 OH OH OH CH3-CH-CH2-OH CH3 Ethylene glycol Glycerol Ethane-1,2-diol Propane -1,2,3-triol CH3-C-OH CH3 CH3