Chapter 2

• For kinetic enolate use:

  • Low temperature
  • Strong hindered base (LDA, Ph3CLi)
  • Excess of base
  • Small cation (Li)
  • Addition of ketone to the base
• For thermodynamic enolate use:

  • Higher temperature
  • Unhindered base
  • Excess of ketone
  • Large cation (K)
  • Base to ketone
• Aldehyde enolate alkylation:

  Not possible, auto-condensation

  
• Ketone enolate alkylation:

  Possible but polyalkylation OR low selectivity
• Ester enolate alkylation:

  Possible but

  • Fragmentation to ketene with high temperature
  • Possible auto-condensation (prevent with low temperature and t-Bu ester)
• Acid enolate alkylation:

  Very reactive but low solubility
• Amide enolate alkylation:

  Very reactive and stable but hard hydrolysis
• Stereoselectivity of enolate:

  For ketones: Z

  For esters: E

  For amides: Z

  
• E enolate is kinetic, gives anti aldol

  Z enolate is thermodynamic, gives syn aldol