Dichloromethane → Ethyl 1-oxa-6-azaspiro[2,5]octane-6-carboxylate

Participants

Reaction Steps

A solution of 47% sodium hydroxide (15 ml), ethyl 4-oxopiperidine-1-carboxylate (4.53 ml, 30 mmol), trimethylsulphonium methanesulphonate (7.36 g, 39 mmol) (Syn. Comm., 1985, 15, 749) and dichloromethane (30 ml) was heated to 50° C. for 16 h, cooled, diluted with water (30 ml), and extracted with dichloromethane. The combined extracts were dried over sodium sulphate and evaporated. The residue was purified by flash column chromatography on silica, eluting with 2% methanol/dichloromethane to give the product as a mobile yellow oil (4.0 g), MS (+EI)m /z 185; 1H NMR (360 MHz) (CDCl3) 4.15 (2H, q, J7.1 Hz), 3.78 (2H, brs), 3.46 (1H, ddd, J3.7, 9.6, 13.3 Hz), 2.71 (2H, s), 1.87-1.79 (2H, m), 1.49-1.43 (2H, m), 1.28 (3H, t, J7.1 Hz).

Provenance & Evidence