Methyl iodide → Ethyl 8-methyl-1,4-dioxaspiro[4.5]decane-8-carboxylate

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Reaction Conditions

Reaction Steps

Ethyl 1,4-dioxaspiro[4.5]decane-8-carboxylate (Int-18a, 2.14 g, 10 mmol) was dissolved in dry THF (20 mL) and the solution was cooled to −78° C. LDA (1.8 M in THF, 6.6 mL) was added to the mixture dropwise and the mixture was stirred for 15 min. Then CH3I (1.87 mL, 30 mmol) was added to the mixture at −78° C. and the reaction was allowed to warm up to room temperature. The reaction was stirred overnight. NH4Cl (aq.) was added to quench the reaction which was extracted with ethyl acetate (50 mL×3). The combined organics was washed with water and brine and dried over Na2SO4. After concentration, the residue was purified by column chromatography (0-50% ethyl acetate in hexane) which gave ethyl 8-methyl-1,4-dioxaspiro[4.5]decane-8-carboxylate (Int-18b) (2.09 g) as an oil. HPLC-MS tR=1.68 min (UV254 nm); mass calculated for formula C12H20O4 228.1, observed LCMS m/z 229.1 (M+H).

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