1-O-tert-butyl 4-O-methyl 4-[(2E)-2-tert-butylsulfinyliminoethyl]piperidine-1,4-dicarboxylate → Tert-butyl 2-(tert-butylsulfinyl)-1-oxo-3-phenyl-2,8-diazaspiro[4.5]decane-8-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a −78° C. solution of 1-tert-butyl 4-methyl 4-{(2E)-2-[(tert-butylsulfinyl)imino]ethyl}piperidine-1,4-dicarboxylate (358 mg, 0.921 mmol) in ether (10 mL) was added phenyllithium (1.8 M, 1.6 mL, 3.1 mmol). The reaction was warmed to 0° C. After 1 h the reaction was quenched by the addition of saturated aqueous ammonium chloride and extracted with dichloromethane (3×). The combined organic layers were dried over MgSO4, filtered, and concentrated under reduced pressure. The crude product was purified by silica gel chromatography, eluting with a gradient of 2 to 55% ethyl acetate:hexanes to give the title compound (50 mg). MS: m/z=435.2 (M+1).

Provenance & Evidence