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

Participants

Reaction Steps

A mixture of the amide-alcohol (2.0 g) prepared in Example 15, dioxane (50 ml) and 20 % sulfuric acid (30.0 g) is refluxed with stirring at 88° to 89° C for 1 hour. The reaction mixture is concentrated to one third of the original volume, diluted with water (50 ml) and cooled in an ice bath. The precipitate is collected by filtration to yield cis-1,3-dibenzyl-hexahyrofuro[3,4-d]imidazole-2,4-dione (1.36 g, 95 %). M.P. 100° to 103° C. [α]D20 + 16.4° (C = 2 in CHCl3). The infrared spectrum of the sample is identified with that of the authentic sample.

Provenance & Evidence