Diisopropylethylamine → (2S,5R)-6-(allyloxy)-2-((tert-butyldimethylsilyloxy)methyl)-4-methyl-1,6-diazabicyclo[3.2.1]oct-3-en-7-one

Participants

Reaction Steps

To a solution of O-allyl-N-((3R,6S)-6-((tert-butyldimethylsilyloxy)methyl)-4-methyl-1,2,3,6-tetrahydropyridin-3-yl)hydroxylamine (Intermediate 12, 2 g, 6.40 mmol) and N,N-diisopropylethylamine (4.46 mL, 25.60 mmol) in acetonitrile (555 mL) at 0° C. was added triphosgene (0.760 g, 2.56 mmol) as a solution in acetonitrile (45 mL). The triphosgene solution was added via syringe pump at a rate of 0.1 mL/min. Once addition was complete the reaction was stirred at room temperature overnight. The reaction mixture was concentrated to dryness, diluted with ethyl acetate, washed with water and brine, dried over magnesium sulfate, filtered and concentrated. The aqueous washes were found to contain some product and were extracted twice with ethyl acetate. The combined organics were dried over magnesium sulfate, filtered and combined with previous extracts. Silica gel chromatography (0%-20% ethyl acetate/hexanes) afforded the desired product (1.980 g, 91%) as a light orange oil.

Provenance & Evidence