2(1H)-Pyrimidinone, tetrahydro-1,3-dimethyl- → Dimethyl bicyclo[3.3.1]nonane-1,5-dicarboxylate

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Reaction Conditions

Reaction Steps

To a pre-cooled (−78° C.) solution of lithium diisopropylamide (86 mL, 172 mmol) in tetrahydrofuran (400 mL) was added DMPU (70.4 g, 550 mol) dropwise, followed by an addition of dimethyl 1-(3-chloropropyl)cyclohexane-1,3-dicarboxylate (30 g, 114.5 mmol) in anhydrous THF (50 mL) within 20 min. After stirring at −78° C. for 30 min, the reaction was allowed to warm up to room temperature over a period of 1.5 h, and then quenched with saturated NH4Cl (100 mL). The mixture was concentrated under reduced pressure and then diluted with water (300 mL). The resulting aqueous mixture was extracted with DCM (4×100 mL) and the combined organic layer was washed with water (100 mL) and brine (100 mL), dried over Na2SO4 and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, petroleum ether/ethyl acetate=30/1) to afford 15.5 g (60%) of the title compound, dimethyl bicyclo[3.3.1]nonane-1,5-dicarboxylate as a light yellow oil. ESI-MS m/z: 227 (M+H)+.

Provenance & Evidence