反应详情

温度

45 °C

Methylation. 3-Ethyl-2-formyl-1-hydroxy-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene (48.2 g, 0.185 mol) was stirred with toluene (650 mL), and potassium hydroxide 85% (19.5 g, 0.296 mol) was added in one portion. The mixture was heated to 45° C. and dimethyl sulfate (35 g, 0.278 mol) was added during 0.5 h at 45°-50° C. The heating was continued for an additional 0.5 h at 50° C. The mixture was cooled to 20° C., neutralized with 5% hydrochloric acid, washed with water (50 mL), and then finally washed with brine (30 mL). Solvent was removed by distillation and the residue distilled to give 3-ethyl-2-formyl-1-methoxy-5,5,8,8-tetramethyl-5,6,7,8-tetrahydronaphthalene (40.6 g), GLC purity 98%. Crystallization from hexane gave 27 g material, GLC purity 99%. 1H-NMR (CDCl3) δ10.38 (1H, s), 6.97 (1H, s), 3.85 (3H, s), 2.89 (2H, q), 1.64 (4H, s), 1.40 (6H, s), 1.28 (6H, s), 1.20 (3H, t). 13C-NMR (CDCl3) δ192.0 (1C, d), 165.3 (1C, s), 153.6 (1C, s), 144.4 (1C, s), 135.7 (1C, s), 125.3 (1C, s), 124.1 (1C, d), 66.0 (1C, q), 38.1 (1C, t), 35.4 (1C, s), 34.8 (1C, t), 34.3 (1C, s), 31.8 (2C, q), 29.8 (2C, q), 26.6 (1C, t), 15.7 (1C, q). IR (KBr) 1275, 1263 cm-1, MS (M/e) 274.2 (M+, 17.1), 258.1 (100.0), 260.3 (20.3), 128.1 (15.1).

1. additionwas added in one portion
2. temperatureThe mixture was cooled to 20° C.
3. washwashed with water (50 mL)
4. washfinally washed with brine (30 mL)
5. customSolvent was removed by distillation
6. distillationthe residue distilled