Water → (2S,4S)-4-acetylthio-1-(4-nitrobenzyloxycarbonyl)-2-[5-(4-nitrobenzyloxycarbonylamino)-1,3-dioxan-2-yl]pyrrolidine

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Reaction Steps

A solution of 2-(4-nitrobenzyloxycarbonyl)amino-1,3-propanediol (1.42 g), (2S,4S)-4-acetylthio-2-formyl-1-(4-nitrobenzyloxycarbonyl)pyrrolidine (1.00 g) and 4-toluenesulfonic acid (0.30 g) in toluene was refluxed for 2 hours with removing water under azeotropic condition. The reaction mixture was poured into a mixture of water and ethyl acetate. The organic layer was separated, washed with brine, dried over magnesium sulfate and evaporated. The residue was chromatographed on silica gel (80 ml) and eluted with a mixture of acetone and dichloromethane (1:9, V/V) to give (2S,4S)-4-acetylthio-1-(4-nitrobenzyloxycarbonyl)-2-[5-(4-nitrobenzyloxy- carbonylamino)-1,3-dioxan-2-yl]pyrrolidine (1.47 g).

Provenance & Evidence