Thioacetic acid → (2S,4S)-4-acetylthio-1-(4-nitrobenzyloxycarbonyl)-2-[1-(4-nitrobenzyloxycarbonyl)-2-imidazolin-2-yl]pyrrolidine

Participants

Reaction Steps

(2S,4R)-4-Hydroxy-1-(4-nitrobenzyloxycarbonyl)-2-[1-(4-nitrobenzyloxycarbonyl)-2-imidazolin-2-yl]pyrrolidine (655 mg) and triphenylphosphine (0.51 g) were dissolved in tetrahydrofuran (20 ml) at 0° C. To this solution was added dropwise a solution of diethyl azodicarboxylate (0.30 ml) in tetrahydrofuran (5 ml) with stirring for 30 minutes, followed by addition of a solution of thioacetic S-acid (0.14 ml). Stirring was continued at ambient temperature for 2 hours. The reaction mixture was diluted with ethyl acetate, washed with saturated sodium bicarbonate and brine, dried over magnesium sulfate and evaporated. The obtained oily residue was subjected to a column chromatography on silica gel and eluted with a mixture of dichloromethane and acetone (20:1, V/V) to give (2S,4S)-4-acetylthio-1-(4-nitrobenzyloxycarbonyl)-2-[1-(4-nitrobenzyloxycarbonyl)-2-imidazolin-2-yl]pyrrolidine (1.2 g).

Provenance & Evidence