Tetrahydrofuran → HCID 67267704, compound

Participants

Reaction Conditions

Reaction Steps

To a pre-cooled (0° C.) solution of methyltriphenylphosphonium bromide (286 mg, 0.8 mmol, 2 equiv) in THF (3 ml) was added n-butyllithium (0.49 ml of 1.6 M solution in hexanes, 0.78 mmol, 1.95 equiv) dropwise. The reaction mixture was stirred at 0° C. for 30 min. A solution of crude aldehyde 30b (ca 0.4 mmol) in THF (1.5 ml) was added and the mixture was stirred at 0° C. for 30 min and quenched with a saturated aqueous ammonium chloride solution (3 ml). The solvent was removed under reduced pressure, and the aqueous residue was extracted with ethyl acetate (3×3 ml). The combined organic extracts were dried over anhydrous sodium sulfate and concentrated in vacuo. Purification by flash column chromatography on silica (7% EtOAc/hexanes) afforded pure olefin 31b (96 mg, 73%) as a yellowish oil: [α]22D=−21.29 (c=0.7, CHCl3); TLC Rf=0.66 (silica gel, 33% EtOAc/hexanes); 1H NMR (600 MHz, CDCl3) δ 8.42 (s, 1H), 7.44 (dd, J=1.8 Hz, 7.8 Hz, 1H), 7.18 (d, J=7.8 Hz, 1H), 5.95-5.88 (m, 1H), 5.12 (d, J=16.8 Hz, 1H), 5.04 (d, J=10.8 Hz, 1H), 4.54 (d, J=5.4 Hz, 1H), 2.97-2.93 (m, 1H), 2.74-2.68 (m, 1H), 2.60-2.56 (m, 1H), 2.30 (s, 3H), 1.96 (s, 3H), 0.98 (t, J=7.8 Hz, 9H), 0.64 (q, J=7.8 Hz, 6H); 13C NMR (100 MHz, CDCl3) δ 153.9, 149.8, 140.9, 139.8, 136.5, 135.0, 130.9, 122.4, 115.2, 87.2, 51.8, 39.2, 18.4, 13.4, 7.2, 5.5; HRMS calcd for C20H31NOSi+H+ 330.2253 found 330.2258 [M+H+].

Provenance & Evidence