m-Chloroperbenzoic acid → Benzyl 7-oxa-3-azabicyclo[4.1.0]heptane-3-carboxylate

Participants

Reaction Steps

A solution of benzyl 5,6-dihydropyridine-1(2H)-carboxylate (9.93 g, 45.76 mmol) in CH2Cl2 (75 mL) was cooled to 0° C. (ice/water bath), Solid m-chloroperoxybenzoic acid (77%, 15.38 g, 1.5 equiv) was added. After 10 min, the reaction mixture was warmed slowly to rt. A white precipitate formed after 1 h. After stirring for another 1 h, LC-MS showed the reaction was complete. The mixture was diluted with ether (300 mL), washed by with 5% aq NaOH (2×40 mL), 25% aq Na2S2O3 solution (3×20 mL) and brine (30 mL), and dried over Na2SO4. After concentration, the residue was purified by flash chromatography (120 g silica gel column, 12%-70% EtOAc in hexanes gradient, 2nd UV peak) to afford benzyl 7-oxa-3-azabicyclo[4.1.0]heptane-3-carboxylate (7.87 g, 74% yield). LC-MS (3 min) tR=1.41 min., m/z 234 (M+1).

Provenance & Evidence