Bis(2-pyridyl) ketone → (Z)-Hex-2-enoic acid

Participants

Reaction Steps

Prepared as above from 150.0 mg (0.35 mmol) of the pyridyl ketone, 308.2 mg (0.70 mmol) of (4-carboxybutyl)triphenylphosphonium bromide, and 1.4 mL (1.4 mmol) of 1.0M t-BuOK in 1.5 mL of THF at 0° C. for 1.5 hr. Flash chromatography followed by preparative HPLC with MeOH-AcOH-CH2 Cl2 (3.5:1.5:95) furnished 107.9 mg 60.2%) of (E)-hexenoic acid and 35.4 mg (19.8%) of (Z)-hexenoic acid (E/Z=3:1). The title (E)-isomer was characterized as follows: mp 86-90° C.; 1H NMR (CDCl3) δ 8.55 (br s, 1H), 8.45 (d, J=4.7 Hz, 1H), 8.25 (s, 1H), 8.04 (d, J=8.1 Hz, 2H), 7.47 (d, J=8.0 Hz, 1H), 7.29 (d, J=8.2 Hz, 2H), 7.21 (m, 1H), 7.12 (distorted t, J=~5.1 Hz, 1H), 6.19 (t, J=7.5 Hz, 1H), 3.44 (dt, J=7.0, 6.7, Hz, 2H), 2.34 (t J=7.1 Hz, 2H), 2.25 (dt, J=7.4, 7.3 Hz, 2H), 1.68-0.82 (m, 19H); FDMS 516 (M+1). Anal. (C31H37N3 O4) C, H, N.

Provenance & Evidence