Potassium Carbonate → tert-Butyl 3-ethynylpiperidine-1-carboxylate

Participants

Reaction Steps

To solution of Example 1C (2 g, 9.38 mmol) in methanol (20 mL) was added potassium carbonate (3.89 g, 28.1 mmol) and the mixture was stirred for 30 minutes. Dimethyl 1-diazo-2-oxopropylphosphonate (3.60 g, 18.76 mmol) was added and the mixture was stirred for 12 hours. The mixture was filtered through diatomaceous earth and concentrated to afford crude material which was purified by column chromatography (silica gel, 15% ethyl acetate in hexane) to afford the title compound. 1H NMR (300 MHz, CDCl3): δ 1.41 (s, 9H), 1.55-1.59 (m, 1H), 1.67-1.69 (m, 2H), 1.96-1.99 (m, 1H), 2.06-2.07 (m, 1H), 2.43-2.44 (m, 1H), 2.93-3.02 (m, 2H), 3.69-3.75 (m, 1H), 3.9-4.0 (m, 1H).

Provenance & Evidence