CO[C:3]1[CH2:12][C:11]([O:13]C)=[C:10]2[CH:5]([CH2:6][CH2:7][N:8]([CH3:15])[CH2:9]2)[CH:4]=1.CN1CCC2C(C(=O)CC(=O)C2)C1.[CH3:29][CH2:30][C:31](/[C:33](/[CH3:36])=[N:34]/O)=O>C(O)(=O)C.[Zn]>[CH2:30]([C:31]1[C:12]2[C:11](=[O:13])[CH:10]3[CH:5]([CH2:6][CH2:7][N:8]([CH3:15])[CH2:9]3)[CH2:4][C:3]=2[NH:34][C:33]=1[CH3:36])[CH3:29]1,2,3,4,4a,7-Hexahydro-6,8-dimethoxy-2-methylisoquinoline (0.56 g, 2.68 mmol) was heated to 90°-100° in 70% aqueous acetic acid (10 ml) to hydrolyze the bis(enolether) to the octahydro-2-methylisoquinolin-6,8-dione. To the hot solution was added zinc dust (0.6 g, 9.25 mmol) and 2-isonitroso-3-pentanone (0.7 g, 6.1 mmol). The mixture was refluxed for 3 hours, cooled and filtered to remove zinc and zinc acetate. The filtrate was concentrated to dryness on a rotary evaporator and the residue was dissolved in dichloromethane. To the solution was added ammonium hydroxide and the layers were separated. The organic layer was washed with brine and dried over anhydrous sodium sulfate and concentrated to give the crude product. Chromatography of the crude product on Alumina III afforded 3-ethyl-2,6-dimethyl-4,4a,5,6,7,8,8a,9-octahydro-1H-pyrrolo[2,3-g]isoquinolin-4-one as a white solid (0.19 g, 29% yield).
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