Water → 3-Methylene-piperidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

A 2.5 M hexane solution of n-BuLi (4.86 mL, 12.15 mmol) was added to a suspension of methyltriphenylphosphonium bromide (4.34 g, 12.15 mmol) in Et2O (100 mL) at 0° C. The mixture was stirred at room temperature for 10 min. A solution of tert-butyl 3-oxopiperidine-1-carboxylate (2.2 g, 11.04 mmol) in ether (10 mL) was added dropwise. The resultant mixture was stirred at room temperature for 1 h, at reflux for 30 min, and cooled to room temperature. After the addition of water (30 mL), the two phases were separated. The aqueous phase was extracted with ether (3×60 mL). The combined ether extracts were washed with brine (20 mL), dried (MgSO4) and concentrated. Silica gel chromatography, eluting with 0 to 15% ethyl acetate in hexane, gave a colorless liquid (1.0 g, 46%). 1H NMR (400 MHz, chloroform-d) δ ppm 4.61-4.96 (2H, m), 3.87 (2H, s), 3.25-3.55 (2H, m), 2.09-2.39 (2H, m), 1.54-1.73 (2H, m), 1.46 (9H, s).

Provenance & Evidence