| 摘要 |
alpha -Loweralkylfurocoumarins are produced by forming a beta -haloalk-2-enyl, e.g., beta -haloallyl, ether of a hydroxycoumarin having an active hydrogen in the position ortho to the hydroxy group, and heating the formed ether, preferably in dimethylaniline or like basic amine solvent. An abnormal Claisen rearrangement produces a novel o-hydroxy-( beta -haloalk-2-enyl) coumarin intermediate which can be dehydrohalogenated directly without isolation to the desired alpha -loweralkylfurocoumarin, e.g., alpha -methylfurocoumarin. |
