Dimethyl Carbonate → Methyl 6-oxospiro[4.5]decane-7-carboxylate

Participants

Reaction Steps

To a suspension of 60% sodium hydride (4.59 g) and potassium tert-butoxide (1.52 g) in tetrahydrofuran (100 mL) was added dimethyl carbonate (7.89 mL) under argon atmosphere at 85° C. To this mixture was added dropwise a solution of spiro[4.5]decan-6-one (8.74 g) obtained in the same manner as in Step 1 in tetrahydrofuran (70 mL) over 1.5 hours. The reaction mixture was heated under reflux for 3 hours. After ice-cooling, to the reaction mixture were added successively acetic acid (7.3 mL), water (85 mL) and ethyl acetate (175 mL), followed by separation of the organic layer. The organic layer was washed with saturated brine, dried and concentrated. The residue was purified by column chromatography on silica gel (ethyl acetate:hexane (volume ratio)=1:100 to 1:90) to give 6-oxo-spiro[4.5]decane-7-carboxylic acid methyl ester (9.99 g).

Provenance & Evidence