1: 62 percent / iodine / benzene / 4 h / Heating 2: N-bromosuccinimid (NBS), benzoyl peroxide / CCl4 / 1.5 h / Heating 3: 1,5-diazabicyclo<4.3.0>non-5-ene (DBN) / tetrahydrofuran / 48 h / 5 °C 4: 92 percent / NaOMe / tetrahydrofuran; methanol / 0.25 h / 80 °C View Scheme

1: 1.) hydrazine hydrate, 2.) KOH / 1.) triethylene glycol, 110 deg C, 60 min, 2.) 140 deg C, 2 h 2: 66 percent Chromat. / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 5 h / Ambient temperature 3: 62 percent / iodine / benzene / 4 h / Heating 4: N-bromosuccinimid (NBS), benzoyl peroxide / CCl4 / 1.5 h / Heating 5: 1,5-diazabicyclo<4.3.0>non-5-ene (DBN) / tetrahydrofuran / 48 h / 5 °C 6: 92 percent / NaOMe / tetrahydrofuran; methanol / 0.25 h / 80 °C View Scheme

1: 66 percent Chromat. / 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) / benzene / 5 h / Ambient temperature 2: 62 percent / iodine / benzene / 4 h / Heating 3: N-bromosuccinimid (NBS), benzoyl peroxide / CCl4 / 1.5 h / Heating 4: 1,5-diazabicyclo<4.3.0>non-5-ene (DBN) / tetrahydrofuran / 48 h / 5 °C 5: 92 percent / NaOMe / tetrahydrofuran; methanol / 0.25 h / 80 °C View Scheme