1: triethyl phosphite / ethanol / 70 - 78 °C 2: thionyl chloride / toluene / 3 h / Reflux View Scheme

triethyl phosphite in ethanol T=70 - 78°C;

thionyl chloride; N,N-dimethyl-formamide 3 h; Heating;

1: 90 percent / sulfuric acid / 1.5 h / Heating 2: 50 percent / dimethylformamide 3: 86 percent / N-bromosuccinimide; benzoyl peroxide / CCl4 / 5 h / Heating 4: 80 percent / t-BuOK / methanol / 1 h / 0 °C 5: 93 percent / sodium hydroxide / methanol; H2O / 0.17 h / Heating View Scheme