Regioselective intramolecular asymmetric cyclization of symmetrical open chain triketone

The title reactions performed with (S)-α-amino acids or their derivatives as chiral sources were found to regioselectively give enantiomeric pairs of optically active 4-acetyl-3, 4-dimethyl-2-cyclohexenone (R)(+)- and (S)(−)- 4 ), 16–25% e.e., and those of optically active 6-acetyl-3,6-dimethyl-2-cyclohexenone((R)(+)- and (S)(−)- 5 , 54–59% e.e., from the open chain triketone( 3 ).