Hydrochloric Acid → (3AS,6aR)-1,3-dibenzyltetrahydro-1H-furo(3,4-d)imidazole-2,4-dione

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Reaction Steps

A solution of (4S,5R)-1,3-dibenzyl-5-methoxycarbonyl-2-oxoimidazolidine-4-carboxylic acid (mp., 149°-150° C., [α]36525 =-27.6° at c=1 in DMF, 368 mg) in isopropanol (6 ml) was added dropwise to a mixture of sodium borohydride (98 mg) and isopropanol (8 ml) at 5°-10° C. The obtained mixture was allowed to warm up to room temperature for 20 hours. Then, 1N hydrochloric acid (10 ml) was added to the reaction mixture. The mixture was stirred at 55°-60° C. for 30 minutes and concentrated under reduced pressure. The residue was extracted with chloroform (30 ml) and water (30 ml). The chloroform layer was washed successively with 5% aqueous sodium hydrogen carbonate and water, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by chromatography on silica gel column to yield (3aS,6aR)-1,3-dibenzylhexahydro-1H-furo[3,4-d]imidazole-2,4-dione (82 mg). M.P., 116°-117° C. [α]D25 =+61.2° (c=1, CHCl3).

Provenance & Evidence