methyl 7-[bis-(tert-butoxycarbonyl)amino]-4H-furo[2,3-c]-chromene-6-carboxylate → methyl cis-(3aRS,9bRS)-7-[bis-(tert-butoxycarbonyl)amino]-1,3a,4,9b-tetrahydro-2H-furo[2,3-c]chromene-6-carboxylate

Participants

Reaction Steps

A solution of methyl 7-[bis-(tert-butoxycarbonyl)amino]-4H-furo[2,3-c]-chromene-6-carboxylate (Intermediate 3, 0.15 g) in a mixture of dioxane (15 mL) and acetic acid (1.5 mL) was treated under an atmosphere of nitrogen with palladium on carbon (10%, 0.02 g). The mixture was stirred and the nitrogen was replaced by hydrogen then the mixture was stirred under an atmosphere of hydrogen for 3 hours. The mixture was filtered through Celite, the pad was washed thoroughly with dioxane and the filtrate was evaporated to dryness to give methyl cis-(3aRS,9bRS)-7-[bis-(tert-butoxycarbonyl)amino]-1,3a,4,9b-tetrahydro-2H-furo[2,3-c]chromene-6-carboxylate (0.15 g) as a gum.

Provenance & Evidence