6-Methoxy-alpha-tetralone → 6-Methoxy-1-methylene-1,2,3,4-tetrahydronaphthalene

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a dry 500 mL 3-necked round bottom flask equipped with a reflux condenser and magnetic stir bar, was charged sodium hydride (3.0 g, 172.89 mmol). The reaction flask was put under nitrogen, and 35 mL of anhydrous DMSO was added. The reaction mixture was heated to 70-75° C., and stirred at that temperature until the evolution of hydrogen ceased. The reaction mixture was cooled to room temperature and additional 25 mL of DMSO was added. Methyltriphenylphosphonium iodide (46.57 g, 115.26 mmol) was added in portions over a period of 1 h. 25 mL of additional DMSO was added to facilitate easy stirring. After the completion of addition, the reaction mixture was stirred for 20 minutes. 6-methoxytetralone (10.156 g, 57.63 mmol) dissolved in 10 mL of anhydrous DMSO was added to reaction mixture. Then, the reaction mixture was heated to 60-65° C., and stirred at that temperature for 8 h. The reaction mixture was poured into a 500 mL Erlenmeyer flask containing 150 mL of crushed ice and 150 mL of hexanes. The resulting mixture was stirred vigorously for 15 min, and then extracted with hexanes. The combined organic layers were washed DMSO:Water (1:1) and then dried over anhydrous sodium sulfate, filtered and evaporated under reduced pressure. Purification by flash column chromatography (silica gel 3:97 EtOAc:Hexanes) yielded 9.42 g of 27 as white solid (94%). Rf: 0.71, (30:70, EtOAc:Hexanes).

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