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 =-27.7° at c=1 in DMF, 368 mg) in tetrahydrofuran (3 ml) and isopropanol (0.50 g) was added dropwise to a mixture of sodium borohydride (100 mg) and tetrahydrofuran (3 ml) at 5°-10° C. The obtained mixture was allowed to warm up to room temperature and to react at the same temperature for 5 hours. Then, 1N hydrochloric acid (10 ml) was added dropwise to the reaction mixture. The mixture was stirred at 55°-60° C. for 30 minutes. Chloroform (30 ml) and water (30 ml) were added to the mixture. Aqueous layer was separated from organic layer and extracted once with chloroform. The organic layers were combined, washed successively with water, 5% aqueous sodium hydrogen carbonate and water, dried over anhydrous magnesium sulfate and concentrated under reduced pressure to give (3aS,6aR)-1,3-dibenzylhexahydro-1H-furo[3,4-d]imidazole-2,4-dione (314 mg). M.P., 116°-117° C. [α]D25 =+61.1° (c=1, CHCl3).

Provenance & Evidence