Ammonia → 14-Methoxydihydromorphinone

Participants

Reaction Steps

To a solution of (4R,4aS,7aR,12bS)-9-(benzyloxy)-4a-methoxy-3-methyl-1,2,3,4,4a,5,6,7a-octahydrospiro[4,12-methanobenzofuro[3,2-e]isoquinoline-7,2′-[1,3]dioxolane] (7.3 g, 16.2 mmol) in MeOH (75 mL) was added conc. HCl (50 mL). The mixture was refluxed for 5 hours then cooled with an ice bath. Concentrated ammonia (25%) was added until pH 8 was reached. The mixture was concentrated and the residues stirred with 10% MeOH/DCM (1 L) overnight. The mixture was filtered and the liquors concentrated to give (4R,4aS,7aR,12bS)-9-hydroxy-4a-methoxy-3-methyl-2,3,4,4a,5,6-hexahydro-1H-4,12-methanobenzofuro[3,2-e]isoquinolin-7(7aH)-one as a dark red oil (5.3 g, quantitative yields).

Provenance & Evidence