Synthesis
In the first step, 9.8 kg (100 mol) of epoxycyclohexane was dissolved in 50 L of N-methylpyrrolidone (NMP). Under continuous stirring, 2.88 kg (120 mol) of magnesium powder was slowly added and the temperature of the reaction system was controlled between -15 °C and -5 °C. Subsequently, 19.5 kg (180 mol) of trimethylchlorosilane (TMSCl) was added dropwise while carbon dioxide gas was vented. The reaction was carried out for 10 h to ensure that the reaction was complete, keeping the temperature below 0 °C. The reaction mixture was filtered and the filtrate was slowly added to a 1 N hydrochloric acid solution. The pH of the mixture was adjusted to 3-4 and extracted with 80 L of ethyl acetate in two portions. The organic phase was washed with a half-saturated aqueous salt solution and concentrated by distillation to give 13.8 kg (95.8 mol) of 2-hydroxycyclohexanecarboxylic acid in 95.8% yield with a cis-trans isomer ratio of 2.3:7.7.
