tert-butyl 5-oxohexanoate

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 5-oxohexanoic acid (25 g, 192 mmol) in t-butyl acetate (600 mL) was added perchloric acid (500 μL, 8.31 mmol) and the resulting pale yellow solution was allowed to stir at room temp, with a drying tube in place, for 65 h. The reaction was diluted with ethyl acetate (400 mL) and then quenched with a mixture of sodium bicarbonate (50 g, 595 mmol) and water (100 mL). The organic layer was extracted with saturated aqueous sodium bicarbonate (5×150 mL), water (1×100 mL), brine (1×75 mL), dried over sodium sulfate, and filtered. The solvent was removed in vacuo to give the title compound (30.55 g, 85%) as a light oil. 1H NMR (500 MHz, chloroform-d) δ 2.50 (t, J=7.2 Hz, 2H), 2.25 (t, J=7.3 Hz, 2H), 2.16 (s, 3H), 1.89-1.83 (m, 2H), 1.46 (s, 9H). The organic layer was extracted with saturated aqueous sodium bicarbonate (5×150 mL), water (1×100 mL), brine (1×75 mL) dried over sodium sulfate filtered The solvent was removed in vacuo