Table 1.

Self-condensation of ketones in the presence of solid acid/base catalysts

EntryKetone (1)CatalystT, °CTime, hConv.1, %Yields of condensates, %*
CnR1R22 (C2n)3 (C3n)4 (C3n)5
1C4MeHMgAlO170310009504
2C5‒C7Et/nPr/ nBuHMgAlO1503100095‒9800
3C6nPrHMgAlO15039909700
4C8‒C15nPentyl‒ ndodecylHMgAlO18012100096‒9900
5C5EtHNb2O518069918730
6C7nBuHNb2O518069828780
7C7EtEtNb2O5180208673000
8C9nBuEtNb2O5180207969000
9C11nBunBuNb2O5180206154000
  • Ketone (1, 2 mmol), catalyst (200 mg), and toluene (3 mL) was heated in a sealed Q-tube reactor. Conv.1, Conversion of compound 1.

  • * Mixture of positional and stereoisomers.

  • Catalyst MgAlO represents calcined Mg/Al-hydrotalcite (Mg/Al = 3:1) and Nb2O5 represents calcined niobic acid.

  • Cyclohexane (3 mL) was used as solvent.