(Z)-Benzaldehyde oxime → tert-Butyl 3-phenyl-1-oxa-2,7-diazaspiro[4.5]dec-2-ene-7-carboxylate

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Reaction Steps

A 10% aqueous sodium hypochlorite solution (2.88 mL, 4.66 mmol) was added dropwise to a solution of tert-butyl 3-methylenepiperidine-1-carboxylate (230 mg, 1.166 mmol) and benzaldehyde oxime (282 mg, 2.332 mmol) in CH2Cl2 (5 mL) at 0° C. After 2 h at 0° C., the mixture was diluted CH2Cl2 (50 mL) and washed with water (10 mL). The aqueous phase was extracted with CH2Cl2 (3×20 mL). The combined organic extracts were washed with brine (10 mL), dried (MgSO4) and concentrated. Silica gel chromatography, eluting with 0 to 15% ethyl acetate in hexanes, gave the expected product as a colorless oil (270 mg, 73% yield). LCMS: (M+Na)+=339.12. 1H NMR (400 MHz, chloroform-d) δ ppm 7.55-7.79 (2H, m), 7.31-7.47 (3H, m), 3.57-3.93 (2H, m), 2.90-3.29 (4H, m), 1.78-2.04 (2H, m), 1.51-1.65 (2H, m), 1.46 (9H, s).

Provenance & Evidence