[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH2:11][CH2:12][OH:13])[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].C1O[C:17]([CH2:19][CH2:20][CH2:21][Cl:22])([CH3:18])OC1.B(F)(F)F.O>[N+](C)([O-])=O>[Cl:22][CH2:21][CH2:20][CH2:19][C:17]1([CH3:18])[C:6]2[C:5](=[CH:4][C:3]([O:2][CH3:1])=[C:8]([O:9][CH3:10])[CH:7]=2)[CH2:11][CH2:12][O:13]1A mixture of 3,4-dimethoxyphenylethyl alcohol (1.72 g, 0.01 mole), 5-chloro-2-pentanone ethylene ketal (1.64 g, 0.01 mole) and 0.5 ml of BF3 etherate in 20 ml of nitromethane is stirred at room temperature under N2 for 4 hours. The reaction mixture is then poured into cold water and extracted with CH2Cl2. The CH2Cl2 solution is washed with water, dried (Na2SO4) and concentrated to an oil. The oil is chromatographed on silica gel with 10% ethylacetate/Skellysolve B as eluate to give 40 g (54% yield) of 1-(3-chloropropyl)-6,7-dimethoxy-1-methyl-isochroman as a white crystalline product, m.p. 77°-79° C. The nmr of the product is consistent with the structure.
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