Tetrahydrothiopyran-4-one → HCID 21878144, compound

Participants

Reaction Conditions

Reaction Steps

A solution of 2-methylpropyl 4-bromophenylcarbamate (Step 1, 10.0 g, 36.7 mmol) in anhydrous tetrahydrofuran (184 mL) at −78° C. under N2 is treated n-butyllithium (1.6M in hexanes, 48.2 mL, 77.1 mmol) dropwise over 20 mins, and the mixture is stirred at −78° C. for 45 mins. The resulting slurry is then treated with a solution of tetrahydro-2H-thiopyran-4-one (4.48 g, 38.5 mmol) in anhydrous tetrahydrofuran (38 mL) dropwise over 5 mins to give an opaque mixture which is allowed to slowly warm to 0° C. with stirring over approximately 2.5 h. The mixture is then quenched by the slow addition of saturated aqueous ammonium chloride (75 mL), water (75 mL) is added, and the layers are separated. The organic phase is washed with water (50 mL) and saline (50 mL), dried over anhydrous magnesium sulfate and concentrated under reduced pressure, and the crude product is recrystallized from EtOAc/hexanes to give the title compound, mp 150-151° C.; MS (ESI−) for C16H23NO3S m/z 308 (M−H)−.

Provenance & Evidence