Sodium Hydroxide → Tert-butyl 7-hydroxy-1,3a,4,9b-tetrahydrochromeno[3,4-b]pyrrole-3(2H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

A solution of boron tribromide (88 mL, 1 M, 88 mmol) in DCM was added to a solution of tert-butyl 7-methoxy-1,3a,4,9b-tetrahydrochromeno[3,4-b]pyrrole-3(2H)-carboxylate (8.6 g, 29 mmol) in DCM (204 mL) over 30 min at −78° C. The reaction mixture was kept at −78° C. for 30 min and then stirred at 0° C. for 30 min. Water (29 mL) and an aqueous solution of NaOH (95 mL, 3 M) were then added, followed by di-tert-butyl dicarbonate (11.4 g, 52.3 mmol). After stirring for 3 h, the layers were separated. The organic layer was washed with 0.1 N HCl, H2O, and the solvent was removed. The resulting residue was triturated using heptane. The crude product was recovered via filtration and was used in the next reaction step without further purification. MS m/z 235 [M−tBu+H]+

Provenance & Evidence