Sodium Hydroxide → methyl (1aRS,7bSR)-5-(2-carboxymethyl-4-fluorobenzenesulfonylamino)-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

1M Sodium hydroxide solution (3 mL) was added to a solution of methyl (1aRS,7bSR)-5-(4-fluoro-2-methoxycarbonylmethylbenzenesulfonylamino)-1,1a,2,7b-tetrahydrocyclopropa-[c]chromene-4-carboxylate (Intermediate 84, 0.438 g) in methanol (6 mL) and the mixture was heated at 50° C. for 2 hours. After cooling, the mixture was evaporated to dryness and the residue was dissolved in ethyl acetate and water and acidified with concentrated hydrochloric acid. The organic layer was dried (Na2SO4) and filtered and the filtrate was concentrated in vacuo, the residue was dissolved in toluene and re-evaporated to give methyl (1aRS,7bSR)-5-(2-carboxymethyl-4-fluorobenzene-sulfonylamino)-1,1a,2,7b-tetrahydrocyclopropa[c]chromene-4-carboxylate (0.422 g) as a white solid.

Provenance & Evidence