反应详情

(3S,4S)-6-(4-tert-Butyldimethylsilyloxyphenyl)sulphonyl-3,4-dihydro-3,4-epoxy-2,2,3-trimethyl-2H-benzo[b]pyran (0.35 g) (see Preparation 14) and 3,6-dihydroxypyridazine (0.273 g) were suspended in absolute ethanol (3 ml), dry pyridine (0.065 ml) was added and the mixture was heated under reflux for 4 days. The solvent was then removed under reduced pressure and the residue chromatographed on silica with 1:99 methanol:ethyl acetate as the eluent to yield (3S,4R)-3,4-dihydro-3-hydroxy-6-(4-hydroxyphenyl)sulphonyl-4-(3-hydroxypyridazin-6-yl)oxy-2,2,3-trimethyl-2H-benzo[b]pyran (0.155 g) as a white solid, m.p. >200° C. Found: C,57.54; H,5.35; N,5.57. C22H22N2O7S, 0.20 ethyl acetate requires C,57.50; H,4.99; N,5.88%.

1. temperaturethe mixture was heated
2. temperatureunder reflux for 4 days
3. customThe solvent was then removed under reduced pressure
4. customthe residue chromatographed on silica with 1:99 methanol