Silane, (1,1-dimethylethyl)[[(1S)-1-[(1E)-2-iodoethenyl]hexyl]oxy]dimethyl- synthesis

Yield:41138-67-4 92%

Reaction Conditions:

Stage #1: (S)-tert-butyl-(1-ethynylhexyloxy)dimethylsilanewith dicyclopentadienylzirconium hydrochloride in dichloromethane at 20; for 1 h;Schlenk technique;Inert atmosphere;
Stage #2: with iodine in dichloromethane at 0 - 20; for 0.25 h;Schlenk technique;Inert atmosphere;

Steps:

5B 5B. (S,E)-tert-butyl(1-iodooct-1-en-3-yloxy)dimethylsilane, SI-9

A modified procedure of Noyori (Suzuki, M. et al., J. Med. C em. 41, 3084-3090 (1998)) was used. A flame dried schlenk flask, evacuated and purged with nitrogen, was charged with alkyne SI-7 (1.89 g, 7.86 mmol). Anhydrous CH₂CI₂ (50 ml) was added and the reaction stirred at r.t.. Zr(Cp)₂HCI (4.05 g, 15.7 mmol) was added as a solid, in portions. The yellow suspension was stirred at r.t. for 1 h. The resulting yellow solution was cooled to 0 °C and iodine (2.19 g, 8.65 mmol) added as a solid, in one portion. The cooling bath was removed and the reaction mixture stirred at room temperature for 15 min. The reaction mixture was poured into water (100 ml) and extracted with 40/60 petroleum ether. This organic phase was washed with saturated Na₂S₂0₃ solution (2 x 100 ml) and brine (100 ml) before being dried (MgS0₄), filtered, and concentrated to give the crude material as a yellow oil. This was purified by flash chromatography, eluting with hexane or 40/60 petroleum ether. The fractions containing product were combined and washed with saturated Na₂S₂0₃ solution (100 ml), dried (MgS0₄), filtered, and concentrated to give the title compound SI-9 (2.67 g, 92%) as a clear, colourless oil. Analytical data consistent with the literature (Luo, F. T. etal., J. Org. Chem. 50, 4762-4766 (1985)). R_f = 0.51 (hexane) v_max (filmVcm-¹ 2955, 2928, 2857, 1607, 1463, 1361, 1254, 1087, 942, 835, 775 *H NMR (400 MHz; CDCI₃) δ_Η = 0.04 (3 H, s, CH₃), 0.05 (3 H, s, CH₃), 0.89 (3 H, m, CH₃), 0.90 (9 H, s, 3 x CH₃), 1.20-1.38 (6 H, m, 3 x CH₂), 1.40-1.53 (2 H, m, CH₂), 4.07 (1 H, m, CH), 6.19 (1 H, dd, J = 14.4, 1.3 Hz, CH), 6.52 (1 H, dd, J = 14.4, 6.0 Hz, CH) 1³C NMR (100 MHz; CDCI₃) 5_C = -4.9 (CH₃), -4.5 (CH₃), 14.0 (CH₃), 18.2 (C), 22.6 (CH₂), 24.5 (CH₂), 25.8 (3 x CH₃), 31.7 (CH₂), 37.5 (CH₂), 75.2 (CH), 75.4 (CH), 149.4 (CH) m/z (CI) MH⁺ not seen, 353 (60%), 311 (52%), 215 (100%), 109 (MH⁺ - HOSi(CH₃)2C(CH₃)3, 60%)

References:

WO2013/186550,2013,A1 Location in patent:Page/Page column 81; 82