[CH3:1][C:2]1[O:7][CH2:6][N:5]([C:8]([CH3:15])([CH:10]([OH:14])[CH:11]([CH3:13])[CH3:12])[CH3:9])[C:4](=[O:16])[C:3]=1[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1.[Cr](Cl)([O-])(=O)=O.[NH+]1C=CC=CC=1.CCOCC>ClCCl>[CH3:1][C:2]1[O:7][CH2:6][N:5]([C:8]([CH3:9])([C:10](=[O:14])[CH:11]([CH3:13])[CH3:12])[CH3:15])[C:4](=[O:16])[C:3]=1[C:17]1[CH:18]=[CH:19][CH:20]=[CH:21][CH:22]=1A solution of 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2,4-dimethylpentan-3-ol (1.7 g) in dichloromethane was added to a stirred mixture of pyridinium chlorochromate (1.81 g) and powdered molecular sieve (4A) in dichloromethane at 20° C. After 5 hours, ether was added, the mixture filtered through hyflo and evaporated. The residue was purified by dry column chromatography on silica gel, eluting with dichloromethane/ethyl acetate to give 2-(2,3-dihydro-6-methyl-4-oxo-5-phenyl-4H-1,3-oxazin-3-yl)-2,4-dimethylpentan-3-one (Compound 1, 0.84 g) as a white solid, m-p. 98.6-101.6° C.
読み込み中…
