Hydrochloric Acid → (3S,4S)-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-4-trimethylsilylethynyl-2-azetidinone

Participants

Reaction Steps

To a solution of (3R,4S)-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-4-trimethylsilylethynyl-2-azetidinone (0.73 g) in dichloromethane (10 ml) was added triethylamine (1 ml). To the solution, trimethylsilyl trifluoromethanesulfonate (1.2 ml) was added at 5° C. and the mixture was stirred for 15 hours at ambient temperature. The reaction mixture was poured into a mixture of ethyl acetate (100 ml), 10% hydrochloric acid (10 ml) and water (100 ml). After stirring for 30 minutes at ambient temp., the organic layer was separated, washed successively with brine, aqueous solution of sodium bicarbonate and brine, dried over magnesium sulfate and concentrated under reduced pressure. The residue was recrystallized from n-hexane to give 0.64 g of (3S,4S)-3-[(R)-1-(tert-butyldimethylsilyloxy)ethyl]-4-trimethylsilylethynyl-2-azetidinone.

Provenance & Evidence