3-(4-chloro-6,7-dihydro-5H-cyclopenta[b]pyridin-2-yl)cyclopent-2-enone → 3-(4-chloro-6,7-dihydro-5H-cyclopenta[b]pyridin-2-yl)cyclopent-2-enol
Reaction equation
[Cl:1][C:2]1[CH:7]=[C:6]([C:8]2[CH2:12][CH2:11][C:10](=[O:13])[CH:9]=2)[N:5]=[C:4]2[CH2:14][CH2:15][CH2:16][C:3]=12>C1COCC1>[Cl:1][C:2]1[CH:7]=[C:6]([C:8]2[CH2:12][CH2:11][CH:10]([OH:13])[CH:9]=2)[N:5]=[C:4]2[CH2:14][CH2:15][CH2:16][C:3]=12Participants
3
Conditions
- Temperature
- 55 °C
Procedure
A 25-mL round bottom flask was charged with 3-(4-chloro-6,7-dihydro-5H-cyclopenta[b]pyridin-2-yl)cyclopent-2-enone (0.434 g, 1.85 mmol) and THF (8 mL) at rt. Borane-dimethylsulfide complex (0.22 mL, 2.32 mmol) was added and the resulting solution was stirred at 55° C. for 4 h. After this time, the reaction was quenched with methanol, treated with 2N aqueous HCl (5 drops), and concentrated under reduced pressure. The residue was diluted with methanol and then concentrated under reduced pressure. The residue was then purified by chromatography on silica using hexanes/ethyl acetate (10:0 to 0:10) as the eluent to afford the title compound (0.123 g, 28%) as an off-white solid. MW=235.71. 1H NMR (CDCl3, 500 MHz) δ 7.15 (s, 1H), 6.58 (q, J=2.0 Hz, 1H), 5.06-4.99 (m, 1H), 3.08 (t, J=7.5 Hz, 2H), 2.99 (t, J=7.5 Hz, 2H), 2.97-2.90 (m, 1H), 2.72-2.64 (m, 1H), 2.52-2.44 (m, 1H), 2.15 (quin, J=7.5 Hz, 2H), 1.93-1.85 (m, 1H).