1: 88 percent / DBU / toluene / 3 h / 100 °C 2: 58 percent / CH3COOH / acetone; H2O / 0.17 h / Ambient temperature View Scheme

With  1,8-diazabicyclo[5.4.0]undec-7-ene in  toluene T=100°C; 3 h;