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2) Preparation ofS-CljS^jS-tetramethyl-ljS-cyclopentadienyO-l^jS^-tetrahydroquinoline; [123] The prepared lithium carbamate compound (8.47 g, 42.60 mmol) was put in theSchlenk flask. Tetrahydrofuran (4.6 g, 63.9 mmol) and 45 mL of diethyl ether were sequentially added. After the flask was put in a low temperature bath having the temperature of -2O0C which included acetone and a small amount of dry ice and then agitated for 30 min, tert-BuLi (25.1 mL, 1.7M, 42.60 mmol) were added thereto. At this time, the color of the resulting substance was changed to the red color. While the temperature was maintained at -2O0C, the agitation was performed for 6 hours. The CeCl3-2LiCl solution (129 mL, 0.33M, 42.60 mmol) and tetramethylcyclopentinone (5.89 g, 42.60 mmol) which were dissolved in tetrahydrofuran were mixed with each other in the syringe, and then added to the flask in a nitrogen atmosphere. The temperature was slowly increased to normal temperature. After 1 hour, the thermostat was removed to increase the temperature to normal temperature. After water (15 mL) was added, ethyl acetate was added and then filtered to obtain a filtrate solution. The filtrate solution was transported to the separatory funnel and a hydrochloric acid (2N, 80 mL) was added and then shaken for 12 min. Additionally, the saturated sodium hydrogen carbonate aqueous solution (160 mL) was added to perform neutralization, and the organic layer was extracted. Anhydrous magnesium sulfate was added to the organic layer to remove water and perform the filtration, the filtrate solution was taken, and the solvent was removed. The yellow oil was obtained by using a column chromatography. Hexane : toluene (v/v, 10 : 1). Hexane : ethyl acetate (v/v, 10 : 1). The yield was 40%.[124] 1H NMR(C6D6) : delta 1.00 (br d, 3H, Cp-CH3), 1.63 - 1.73 (m, 2H, quin-CH2), 1.80 (s, 3H, Cp-CH3), 1.81 (s, 3H, Cp-CH3), 1.85 (s, 3H, Cp-CH3), 2.64 (t, J = 6.0 Hz, 2H, quin-CH2), 2.84 - 2.90 (br, 2H, quin-CH2), 3.06 (br s, IH, Cp-H), 3.76 (br s, IH, N-H), 6.77 (t, J = 7.2 Hz, IH, quin-CH), 6.92 (d, J = 2.4 Hz, IH, quin-CH), 6.94 (d, J = 2.4 Hz, IH, quin-CH) ppm. |