Ammonium Chloride → tert-butyl 7-hydroxy-6-oxohexahydropyrrolo[1,2-a]pyrazine-2(1H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of the product from Example 207A (0.20 g, 0.832 mmol) in anhydrous tetrahydrofuran (6 mL) at −78° C. under N2 was added a 1 M solution of lithium bis(trimethylsilyl)amide in tetrahydrofuran (1.25 mL, 1.25 mmol). The resulting mixture was stirred at −78° C. for 20 minutes, and then a solution of 3-phenyl-2-(phenylsulfonyl)-1,2-oxaziridine (0.326 g, 1.248 mmol) in anhydrous tetrahydrofuran (3 mL) was added dropwise. The mixture was stirred at −78° C. for 20 minutes and then warmed to −40° C. and stirred for 2 hours. A solution of NH4Cl (10% in water, 2 mL) was added, and the mixture was allowed to warm to room temperature and partitioned between water and ethyl acetate (5×). The combined organic layers were dried over Na2SO4. The drying agent was removed by filtration, and the filtrate was concentrated in vacuo. The crude product was purified by column chromatography on silica gel using a solvent gradient of 0-10% CH3OH in CH2Cl2 to give the title compound (89 mg, 42%).

Provenance & Evidence