Organic Synthesis

• Alkene to Alkane:

  • H2/Nickel catalyst
  • 423K

  Mechanism

  • Hydrogenation/Electrophilic Addition
• Alkene to haloalkane:

  • Hydrogen halide e.g. HBr, HCl

  Mechanism

  • Electrophilic Addition
• Alkene to dihaloalkane:

  • X2 (halide) e.g. Cl2, Br2, I2
  • room temperature

  Mechanism

  • electrophilic Addition
• Alkene to alcohol:

  • H2O (steam)
  • High Temperature & Pressure
  • H3PO4 Catalyst

  Mechanism/Process

  • Hydrolysis
  • Electrophilic Addition
• Alkane to haloalkane:

  • Halogen e.g. Br
  • UV Light

  Mechanism/Process

  • Electrophilic Substitution
  • Free Radical Substitution
• What is the free radical substitution mechanism for CH4 + Cl2 -> CH3Cl + HCl


  Initiation:

  Cl2 --UV--> 2Cl•

  Propagation:

  CH4 + Cl• -> HCl + •CH3

  •CH3 + Cl2 -> CH3Cl + Cl•

  Termination:

  •CH3 + Cl• ->CH3Cl

  •CH3 + •CH3 -> CH3CH3
• Haloalkane to alcohol:

  • NaOH(aq) (in aqueous solution)

  Mechanism/Process

  • Nucleophilic Substitution
  • Hydrolysis
• Haloalkane to nitrile:

  • CN-/Ethanol (ethanolic cyanide)
  • Heated under reflux

  Mechanism/Process

  • Nucleophilic Substitution
• Haloalkane to Primary Amine:

  • NH3/Ethanol

  Mechanism/Process

  • Nucleophilic Substitution
• Nitrile to Primary Amine:

  • NaBH4 or LiAlH4
  • H2/Nickel catalyst

  Mechanism/Process

  • Reduction (nitriles reduced to primary amines)
• Nitrile to Carboxylic Acid:

  • H2O/HCl, heat

  Mechanism/Process

  • Acid Hydrolysis

  Mechanism

  RCN --(H2O)(H+)--> RCOOH
• Hydroxynitrile to Carboxylic Acid:

  • H2O/HCl, heat
  • Reflux

  Mechanism

  CH2(OH)CN + 2H2O + HCl --(Reflux)--> CH2(OH)COOH + NH4Cl
• Hydroxynitrile to Amine:

  • H2/Nickel catalyst
  • Use NaBH4 or LiAlH4 and dilute acid - dilute H2SO4

  Mechanism: CH2(OH)CN + 4[H] --(LiAlH4 and dilute H2SO4)--> CH2(OH)CH2NH2
• Alcohol to haloalkane:

  • Sodium Halide e.g. NaCl
  • H2SO4 catalyst

  Mechanism/Process

  • Substitution

  Catalyst and sodium halide: $NaCl +$$H2SO4->NaHSO4+$$HCl$

  Mechanism using ethanol : $CH3CH2OH+$$HCl -> CH3CH2Cl+$$H2O$
• Secondary Alcohol to Ketone:

  • K2Cr2O7/H2SO4
  • Reflux

  Mechanism/Process

  • Oxidation

  Mechanism using propan-2-ol to make propanone = CH3CH(OH)CH3 + [O] -> CH3C=OCH3 + H2O

  Colour changes from orange to green in presence of a secondary alcohol
• Alcohol to alkene

  Reagents & conditions

  • H3PO4 or H2SO4 catalyst
  • heat

  Mechanism

  CH3CH2CH2OH->CH2=CHCH3+H2O

  Secondary and Tertiary Alcohols give more than one product