Water → tert-butyl 7-(benzenesulfonylmethyl)-4-oxo-4H-furo[2,3-c]chromene-6-carboxylate

Participants

Reaction Steps

N,N′-dicyclohexylcarbodiimide (0.014 g) was added to a solution of 3-[4-(benzenesulfonylmethyl)-3-tert-butoxycarbonyl-2-hydroxyphenyl]-furan-2-carboxylic acid (Intermediate 21, 0.028 g) and DMAP (0.0003 g) in DCM (5 mL) and the mixture was stirred for 72 hours. Water and DCM were added and the organic layer was separated, dried (MgSO4) and filtered. The filtrate was evaporated to dryness and the residue was purified by chromatography on silica, eluting with a mixture of ethyl acetate and cyclohexane with a gradient of 30-40% to give tert-butyl 7-(benzenesulfonylmethyl)-4-oxo-4H-furo[2,3-c]chromene-6-carboxylate (0.037 g) as a white solid.

Provenance & Evidence