Pyridine → HCID 22846532, compound

Participants

Reaction Steps

A flask was charged with (S)-1-[(tert-Butyldiphenylsilyl)oxy]-3-butyn-2-ol (1) (1.30 g, 4 mmol), triphenylphosphine (2.52 g, 9.60 mmol), THF (30 mL), pyridine (360 mg, 4.56 mmol). To this mixture was added carbon tetrabromide (1.53 g, 4.60 mmol) in THF (10 ml) over a 5 minute period. The resulting reaction mixture was stirred for 45 minutes. Hexanes (50 mL) was added, and the mixture was filtered and concentrated in vacuo. The residue was taken up into hexanes (50 mL), washed with 1 M HCl (40 mL), saturated NaCl (40 mL). The organic extracts were dried (MgSO4) and concentrated by rotary evaporation to yield a yellow oil. Purification by flash silica gel chromatography (98:02 hexane/EtOAc) afforded (R)-2-bromo-1-[tert-butyldiphenylsilyloxy]-3-butyne (4) (1.50 g, 97%) as a colorless oil (Note: this material is unstable and should be used immediately): Rf 0.74 (90:10 hexane/EtOAc); IR (neat) 3308, 1437, 1112, 701 cm-1 ; 1H NMR (CDCl3) δ 7.70 (m, 4 H), 7.42 (m, 6 H), 4.46 (dt, J1 =6.66 Hz, J2 =2.36 Hz, 1 H), 3.91 (ddd, J1 =10.7 Hz, J2 =6.32, Hz, J3 =3.78 Hz, 2H), 2.59 (d, J=2.4 Hz, 2 H), 1.08 (m, 9H); 13C NMR (CDCl3); δ 135.8, 132.8, 129.6, 127.6, 80.3, 75.6, 67.5, 36.2, 26.8, 19.3. ##STR19##

Provenance & Evidence