Hydrochloric Acid → 4-Hydroxy-4-[5-(methoxymethyl)-2-pyridinyl]cyclohexanone

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Reaction Steps

A solution of 2-bromo-5-(methoxymethyl)pyridine (2.61 g, 12.9 mmoles) was dissolved in dry THF (40 mL) under nitrogen and cooled to −78° C. n-Butyllithium (6.20 mL, 15.5 mmoles, 2.5 M in hexane) was added dropwise over 10 minutes to form a black solution. After 15 minutes, a solution of 1,4-dioxa-spiro[4.5]decan-8-one (2.21 g, 14.1 mmoles) in THF was added dropwise over 2 minutes and the mixture was gradually warmed to room temperature over 3 hours. TLC (50% ethyl acetate/hexane) and LC/MS indicated complete conversion. Aqueous HCl (14 mL, 6.0 M) was added and the mixture was stirred for 3 hours at room temperature and then neutralized with NaHCO3/H2O. The mixture was extracted 3 times with ethyl acetate and the combined extracts were adsorbed onto silica gel and chromatographed. The column was eluted with a gradient of hexane to 40% ethyl acetate/hexane. Pure fractions were combined and concentrated to provide the title compound as a pale yellow solid, 1.00 g (33%). LC/MS (positive ion) m/z=236.1 (M+H)+.

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