Hydrochloric Acid → HCID 11126489, compound

Participants

Reaction Steps

(R)-Me-CBS reagent (1.0 M Toluene, 2.14 mL, 2.14 mmol) was transferred into a freshly flame-dried flask, and the toluene was removed in vacuo over 1 day. The CBS reagent was diluted with a THF solution of 5-trimethylsilyl-1-penten-4-yn-3-one (163 mg, 1.07 mmol), and the resultant solution was cooled to −30° C. At −30° C., BH3-Me2S (0.589 mL, 1.18 mmol) was slowly added over 10 min. After addition of BH3-Me2S, TLC analyses indicated that the reaction was complete. Methanol was slowly added, and reaction mixture was slowly warmed to room temperature. The reaction mixture was diluted with diethyl ether, and the resultant organic phase was washed with 2:1 (v:v) NaOH/saturated NaHCO3 solution until the aqueous phase was clear, and then washed with brine. After being dried over MgSO4, the organic phase was removed, diluted with diethyl ether, and to this was added a solution of 0.5 M HCl in methanol (4.5 mL, 2.14 mmol). Precipitates were removed by filtration. The crude product in the solvent mixture was purified by flash column chromatography (hexane/ether 5:1) to provide (3R)-5-trimethylsilyl-1-penten-4-yn-3-ol (0.163 g, 100% yield) as a colorless oil: Rf: 0.4 (hexane/dichloromethane 2:1); [α]D20.0°: −24.1 (c=1, CHCl3); 1H NMR (400 MHz, CDCl3): δ 5.95 (ddd, 1H, J=17.0, 10.1, 5.29 Hz), 5.46 (d, 1H, J=7.0 Hz), 5.21 (d, 1H, J=10.1 Hz), 4.86 (d, 1H, J=3.87 Hz), 2.17 (br s, 1H), 0.16 (s, 9H); 13C NMR (75 MHz, CDCl3) δ 137.0, 116.8, 104.9, 91.3, 63.9, 0.2; IR (neat) v: 3368.7, 2961.3, 2927.0, 2855.3, 2174.4, 1250.9, 843.7 cm−1; HRMS: calculated 154.28, found 154.0817 for [M]+.

Provenance & Evidence