Hydrochloric Acid → HCID 9950554, compound

Participants

Reaction Steps

To a solution of 1-trimethylsilyloxy-6-(S)-methoxy-1-cyclohexene (800 mg, 4 mmol) in tetrahydrofuran (5 ml), a tetrahydrofuran solution containing 1 mol/liter of ethylmagnesium bromide was added and stirred at room temperature for 3 days. This mixture was then cooled to 0° C., and a solution of (3R,4R)-4-acetoxy-3-[(1R)-1-tert-butyldimethylsilyloxyethyl)-2-azetidinone (861 mg, 3 mmol) in tetrahydrofuran (5 ml) was added dropwise to the mixture and stirred at 0° C. for 1 hour. The resultant mixture was subjected to addition of 2N hydrochloric acid and extraction with butyl acetate. The organic phase was washed with a saturated sodium hydrogencarbonate solution and water, and concentrated under a reduced pressure to obtain a crude product of (3S,4R)-3-[(R)-1-((tert-butyldimethylsilyl)oxy)ethyl]-4-[(1R,3S)-3-methoxy-2-oxocyclohexyl]azetidin-2-one. The crude product contained 170 mg of the objective β-isomer. The yield was 16%, and the β:α ratio was 90:10.

Provenance & Evidence