反应详情

15.30 g (52.9 mmol) of 8-(N-benzyloxycarbonylamino)-2-methyleneoctanal and 7.37 ml (67.4 mmol) of isocyanoacetic acid ethyl ester are dissolved in 78 ml of toluene and added dropwise under argon, within a period of 75 minutes, to a suspension of 0.30 g of copper(I) oxide in 76 ml of toluene. The mixture is then stirred for 90 minutes at 30°, cooled to room temperature and filtered, and the clear, bright red filtrate is introduced into a column filled with 250 g of silica gel (particle size 0.04-0.063 mm) and eluted with hexane/ethyl acetate (2:1). Concentration of the suitable fractions by evaporation yields 8.15 g of 5-[8-(N-benzyloxycarbonylamino)oct-1-en-2-yl]-oxazoline-4-carboxylic acid ethyl ester in the form of a colourless honey.

1. filtrationfiltered
2. additionthe clear, bright red filtrate is introduced into a column
3. additionfilled with 250 g of silica gel (particle size 0.04-0.063 mm)
4. washeluted with hexane/ethyl acetate (2:1)
5. customConcentration of the suitable fractions by evaporation