Chloromethyl Methyl Ether → Diethyl 4-(methoxymethoxy)cyclohexane-1,1-dicarboxylate

12.3 g of diethyl 4-hydroxycyclohexane-1,1-dicarboxylate was dissolved in 160 ml of dichloromethane and 26.3 ml of diisopropylethylamine was added thereto followed by ice-cooling. Next, 9.6 ml of chloromethyl methyl ether was added thereto and the reaction mixture was stirred at room temperature for 15 hours. Then the reaction mixture was concentrated and the residue was purified by silica gel column chromatography (eluted with n-hexane/ethyl acetate) to thereby give 11.10 g of the title compound as a colorless oily substance.