Lithium Hexamethyldisilazide → t-Butyl-[2-(4,8-dimethyl-non-1-enyl)-2,5,7,8-tetramethyl-chroman-6-yloxy]-dimethylsilane

Participants

Reaction Conditions

Reaction Steps

To a suspension of 1-bromo-3,7-dimethyl octanyl phosphonium (1.05 mmol) in 20 mL of anhydrous THF at 0° C. was added 1.05 mL of 1 M lithium bis(trimethysilyl)amide in THF. The mixture was stirred at 0° C. for 30 min, and compound iii (1 mmol) in 10 mL of THF was slowly added over a period of 1 h. After being stirred at room temperature for 1 h, the solution was concentrated, diluted with 20 mL of ethyl acetate, and washed, in tandem, with H2O and brine. The residue was purified by flash silica gel chromatography to afford t-butyl-[2-(4,8-dimethyl-non-1-enyl)-2,5,7,8-tetramethyl-chroman-6-yloxy]-dimethylsilane (iv) as colorless oil in 80% yield. 1H NMR (300 MHz, CDCl3) δ 0.11 (s, 6H), 0.86-0.95 (m, 6H), 1.04 (s, 9H), 1.39 (s, 1H), 1.49-1.56 (m, 1H), 1.76-1.86 (m, 1H), 2.01-2.06 (m, 2H), 2.11 (s, 3H), 2.17 (s, 6H), 2.25-2.32 (m, 1H), 2.62 (t, J=6.60 Hz, 2H), 5.30-5.44 (m, 2H).

Provenance & Evidence