Methanol → tert-Butyl 4-ethynylpiperidine-1-carboxylate

Participants

Reaction Steps

To a stirred suspension of tert-butyl 4-formylpiperidine-1-carboxylate (0.427 g, 2.00 mmol), K2CO3 (0.553 g, 4.00 mmol), and MeOH (25 mL) was added all at once the Bestman-Ohira reagent, dimethyl 2-oxo-1-diazo-propylphosphonate (0.461 g, 2.40 mmol, see Synthesis 2004, 1, 59-62). Stirring was continued for 20 hours under nitrogen. The reaction was diluted with Et2O (50 mL), washed with a 2:1 mixture of water and aqueous saturated NaHCO3 (20 mL), dried (Na2SO4), filtered, and concentrated in vacuo. Yield: 253 mg (55%). 1H NMR (400 MHz, CDCl3) δ 3.72 (m, 2H), 3.19 (m, 2H), 2.58 (m, 1H), 2.10 (d, J=2 Hz, 1H), 1.77 (m, 2H), 1.61 (m, 2H), 1.46 (s, 9H).

Provenance & Evidence