Ammonia → (3S,4R)-4-amino-3,4-dihydro-3-hydroxy-6-(3-hydroxyphenyl)sulphonyl-2,2,3-trimethyl-2H-benzo[b]pyran

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Reaction Conditions

Reaction Steps

(3S,4S)-6-(3-tert-butyldimethylsilyloxyphenyl)sulphonyl-3,4-dihydro-3,4-epoxy-2,2,3-trimethyl-2H-benzo[b]pyran (2.2 g) (see Preparation 15) was dissolved in ethanol (25 ml) and 35% aqueous ammonia solution (25 ml) was added. The mixture was heated at 40-50° C. for 24 hours. The solvent was removed under reduced pressure and the residue was chromatographed on silica using 7.5:92.5 methanol:dichloromethane as the eluent to yield (3S,4R)-4-amino-3,4-dihydro-3-hydroxy-6-(3-hydroxyphenyl)sulphonyl-2,2,3-trimethyl-2H-benzo[b]pyran (1.42 g) as a foam. Found: C,54.39; H,5.22; N,3.19. C18H21NO5S, 0.50 CH2Cl2 requires C,54.75; H,5.46; N,3.45%.

Provenance & Evidence