1: 1,4-dioxaspiro[4.5]dec-6-yl-methanol With sodium hydride in tetrahydrofuran T=0°C; 0.5 h; 2: benzyl bromide in tetrahydrofuran T=0 - 20°C; 3 h;

oxalic acid; silica gel in dichloromethane Ambient temperature;

1: Et3N / diethyl ether / 2 h / Ambient temperature 2: NaBH4 / ethanol / 2 h / Heating 3: BF3*Et2O / acetone / 2 h / Heating 4: 1.) n-BuLi / 1.) THF, hexane, 0 deg C, 1 h, 2.) a) -78 deg C, 2 h, b) 0 deg C, 1 h 5: TsOH*H2O / benzene; H2O / 3 h / Heating 6: 1.) m-chloroperbenzoic acid, 2.) Et2NH / 1.) THF, -20 deg C, 20 min, 2.) CCl4, reflux, 10 min View Scheme

Multi-step reaction with 2 steps 1.1: sodium hydroxide / H2O / 3 h / 35 °C1.2: 47 percent / hydroquinone / H2O / 0.5 h / 35 °C2.1: 82 percent / pyridinium para-toluenesulfonate (PPTS) / benzene / 1 h / Heating