反应详情

温度

-78 °C

2,6-Dimethyl-6-(3-methyl-but-2-enyl)-cyclohex-2-enone (5.00 g, 26 mmol) was added to a solution of LDA (prepared from diisopropylamine (3.15 g, 31.2 mmol) and n-BuLi (1.6M in hexane, 19.5 ml, 31.2 mmol)) in THF (50 ml) at −78° C. The mixture was stirred for 1 h at −78° C. Methyl iodide (5.54 g, 39 mmol) was added and the solution was allowed to warm to room temperature over night. The mixture was diluted with MTBE and washed with portions of H2O and brine, dried (MgSO4) and concentrated in vacuo to yield 7 g of a slightly yellow oil which was distilled (bp.42° C./0.005 mbar) to give 4.5 g (84%) of an olfactorily clean oil. 1H-NMR (400 MHz, CDCl3): 5.72-5.68 (m, 1H), 5.63-5.59 (m, 1H), 5.06-4.99 (m, 1H), 2.36-2.08 (m, 4H), 1.70 (s, 3H), 1.59 (s, 3H), 1.15 (s, 3H), 1.12 (s, 3H), 1.07 (s, 3H) ppm. GC/MS (EI): 206 (M+, 15), 191 (8), 137 (19), 123 (25), 109 (100), 96 (34), 91 (9), 81 (28), 67 (24), 41 (33). IR (ATR): 3023s, 2966s, 2926m, 1703vs, 1456s, 1376m, 1203w, 1033s, 713s cm−1.

1. temperatureto warm to room temperature over night
2. washwashed with portions of H2O and brine
3. dry with materialdried (MgSO4)
4. concentrationconcentrated in vacuo
5. customto yield 7 g of a slightly yellow oil which
6. distillationwas distilled (bp.42° C./0.005 mbar)
7. customto give 4.5 g (84%) of an olfactorily clean oil