1: 98 percent / methanol / 72 h / Ambient temperature 2: 48 percent / 85percent aq. KOH, hydrazine hydrate / ethane-1,2-diol; H2O / a) 130-140 deg C, 2 h, b) 210 deg C, 6 h View Scheme

1: 40 percent / SeO2 / tetrahydrofuran / 15 h / Heating 2: 60 percent / Et3N / benzene / 12 h / Heating View Scheme