tert-butyl N-(2-oxospiro[3.3]heptan-6-yl)carbamate

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

Procedure: To a solution of tert-butyl (6-oxospiro[3.3]heptan-2-yl)carbamate (800 mg, 3.55 mmol) in anhydrous THF (15 mL) was added a solution of methyl lithium in THF (2.36 mL, 3 mol/L, 7.50 mmol) at −78° C. under nitrogen. The resulting mixture was stirred at room temperature for 2 h. The reaction mixture was quenched with saturated aqueous ammonium chloride and the mixture was extracted with ethyl acetate. The combined organic layers were washed with brine, dried over anhydrous sodium sulfate, and concentrated under vacuum to afford the title compound (760 mg, crude) as a brown solid, which was which was used to next step without further purification. MS (ESI) m/z 242.2 [M+H]+. The reaction mixture was quenched with saturated aqueous ammonium chloride the mixture was extracted with ethyl acetate The combined organic layers were washed with brine dried over anhydrous sodium sulfate concentrated under vacuum

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

Procedure: To a solution of tert-butyl (6-hydroxyspiro[3.3]heptan-2-yl)carbamate (1.00 g, 4.40 mmol) in DCM (10 mL) was added Dess-Martin periodinane (2.80 g, 6.60 mmol) at ˜0° C. to 10° C. The resulting reaction mixture was stirred at room temperature for 1.5 h. The reaction mixture was treated with aqueous sodium bicarbonate and extracted with DCM. The combined organic layers were washed with brine, dried over anhydrous sodium sulfate and filtered. Concentration under vacuum gave the crude product, which was purified by silica gel column chromatography (22% ethyl acetate in petroleum ether) to afford the title compound (800 mg, 3.55 mmol, 80% yield) as a pale yellow solid. MS (ESI) m/z 226.1 [M+H]+. The resulting reaction mixture extracted with DCM The combined organic layers were washed with brine dried over anhydrous sodium sulfate filtered Concentration under vacuum gave the crude product, which was purified by silica gel column chromatography (22% ethyl acetate in petroleum ether)