[O:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH2:3][C:2]1=O.C1(P(=[CH:30][C:31]([O:33][CH3:34])=[O:32])(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1>CC1C=CC(C)=CC=1>[O:1]1[C:9]2[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=2[C:3]([CH2:30][C:31]([O:33][CH3:34])=[O:32])=[CH:2]1A mixture of 0.4 mol of coumaranone and 0.48 mol of methyl (triphenylphosphoranylidene)acetate in 1 liter of p-xylene is maintained at reflux for 18 h. After cooling to room temperature, the solvent is evaporated off, the residue is taken up in 1 liter of ether, the precipitate is filtered off and washed with ether, the filtrate is concentrated and the expected product is obtained after chromatography on silica (eluent: CH2Cl2).
Wird geladen…