Hydrochloric Acid → (3R,5S)-1-allyloxycarbonyl-3-hydroxy-5-[1-hydroxy-1-(imidazo[5,1-b]thiazol-3-yl)methyl]pyrrolidine

Participants

Reaction Conditions

Reaction Steps

Concentrated hydrochloric acid (2.0 ml) is added dropwise to a solution of 525 mg of (3R,5S)-1-allyloxycarbonyl-3-t-butyldimethylsilyloxy-5-[1-hydroxy-1-(imidazo[5,1-b]thiazol-3-yl)methyl]pyrrolidine (stereoisomer A) in 50 ml of dry acetonitrile under ice cooling (internal temperature 7° C.). The mixture is stirred in this state for 5 min, and the temperature is then raised to 15° C. over a period of 20 min. The reaction solution is concentrated to about 20 ml under reduced pressure, and the concentrate is adjusted to pH 8.5 by addition of 40 ml of a 5% aqueous sodium hydrogencarbonate solution. The mixture is then extracted three times with 100 ml of ethyl acetate. The combined organic layers are dried over magnesium sulfate, and the solvent is removed by evaporation under reduced pressure to give 457 mg of crude (3R,5S)-1-allyloxycarbonyl-3-hydroxy-5-[1-hydroxy-1-(imidazo[5,1-b]thiazol-3-yl)methyl]pyrrolidine (stereoisomer A) as a milky white amorphous material.

Provenance & Evidence