CO.[CH:3]([O:8]C)([O:6][CH3:7])OC.OS(O)(=O)=O.[C:15]([C:23]1C(=O)[O:25][C:26]([C:30]2[CH:35]=[CH:34][CH:33]=[CH:32][CH:31]=2)=[CH:27][C:28]=1[OH:29])(=O)[C:16]1[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=1>O>[C:30]1([C:26]2[O:25][C:15]([C:16]3[CH:17]=[CH:18][CH:19]=[CH:20][CH:21]=3)=[CH:23][C:28](=[O:29])[C:27]=2[C:3]([O:6][CH3:7])=[O:8])[CH:31]=[CH:32][CH:33]=[CH:34][CH:35]=1A 200 ml flask was fitted with a N2 inlet, a magnetic stirring bar and a condenser. 50 mls of methanol, 8.0 gms of trimethyl orthoformate, 5.2 gms of concentrated H2SO4 and 5.0 gms of 3-benzoyl-4-hydroxy-6-phenyl-pyr-2-one were added. The resulting mixture was then refluxed for 3 days, cooled, poured into water and extracted with methylene chloride (300 mls). The organic extracts were combined and washed with water. Removal of the solvent provided 4.4 gms of 2,6-diphenyl-3-methoxycarbonyl-pyr-4-one (85%). Recrystallization from methylene chloride/ether provide material with a melting point=150°-1°.
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