2(1H)-Pyrimidinone, tetrahydro-1,3-dimethyl- → 1-(Carboethoxy)-1-(4-methoxybenzylthio)cyclohexane

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Cool lithium hexamethyldisilazane (8.4 mL of a 1.0M solution in tetrahydrofuran, 8.4 mmol) to -78° C. Add , by cannula transfer, a solution of 1-(carboethoxy)-1-(4-methoxybenzylthio)methane (2.0 g, 8.3 mmol) in tetrahydrofuran (8 mL). Stir for 45 minutes then add a solution of 1-iodo-5-chloropentane (1.94 g, 8.32 mmol) in tetrahydrofuran (8 mL). Stir for 1 hour and add 1,3-dimethyl-3,4,5, 6-tetrahydro -2(1H)-pyrimidinone (DMPU) (1.21 mL, 10.0 mmol). Stir at 0° C. for 4 hours and at room temperature for 6 hours. Cool to -78° C., add lithium hexamethyldisilazane (8.4 mL, 8.4mmol) and stir at room temperature overnight. Quench with saturated ammonium chloride (5 mL) and partition between ethyl acetate (50 mL) and water (50 mL). Separate the organic phase, dry (Na2SO4) and evaporate the solvent in vacuo. Purify by chromatography (6:1 hexane/ethyl acetate) to give 1-(carboethoxy)-1-(4-methoxybenzylthio)cyclohexane as an colorless oil (1.45 g, 56%).

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