Hexamethyldisilazane → (3S)-3-[(1R)-1-(t-butyldimethylsilyloxy)ethyl]azetidin-2-one

Participants

Reaction Conditions

Reaction Steps

A mixture of ethyl (2S,3R)-2-aminomethyl-3-(t-butyldimethylsilyloxy)butanoate (1.38 g) and 1,1,1,3,3,3-hexamethyldisilazane (1.58 ml) was stirred at 70° C. for 15 hours, and then concentrated under reduced pressure. The residue was dissolved in 50 ml of tetrahydrofuran and 1.1N t-butylmagnesium chloride in tetrahydrofuran (15 ml) was added dropwise thereto at room temperature. After stirring for 30 minutes, the reaction mixture was quenched with water (10 ml), and diluted with ethyl acetate (50 ml) and 1N hydrochloric acid in water (20 ml). The aqueous layer was separated and extracted twice with ethyl acetate (25 ml×2) and the combined organic layers were washed in turn with 1N hydrochloric acid in water (20 ml), saturated sodium bicarbonate (20 ml), water (20 ml) and brine (20 ml), dried over magnesium sulfate and evaporated under reduced pressure. The residue was column-chromatographed on silica gel (hexane-ethyl acetate=3:1) to give (3S)-3-[ (1R)-1-(t-butyldimethylsilyloxy)ethyl]-azetidin-2-one (0.841 g).

Provenance & Evidence