Acetaldehyde → 2-Propenal, 3-cyclopentyl-, (2E)-

Participants

Reaction Conditions

Reaction Steps

To a stirred suspension of triphenylphosphoranylidene)acetaldehyde (27, 62.75 g, 200.0 mmol, 1.0 equiv) in anhydrous benzene (400 mL, 4476 mmol) was added cyclopentanecarbaldehyde (26, 21.36 mL, 200.0 mmol) at room temperature. The resulting reaction mixture was then heated at 80° C. for 16 h. When TLC and HPLC showed that the reaction was deemed complete, the reaction mixture was concentrated under reduced pressure. The residue was then directly purified by Combiflash (SiO2) with 0-10% EtOAc/hexane gradient elution to afford (2E)-3-cyclopentylacrylaldehyde (28, 14.4 g, 24.84 g theoretical, 58% yield) as a yellow oil. For 28: 1H NMR (DMSO-d6, 400 MHz) δ ppm 1H NMR (CDCl3, 400 MHz) δ 9.49 (d, 1H, J=7.8 Hz), 6.82 (dd, 1H, J=15.6, 7.8 Hz), 6.08 (dd, 1H, J=15.6, 8.0 Hz), 2.72 (m, 1H), 1.89 (m, 2H), 1.67 (m, 4H), 1.44 (m, 2H); C8H2O (MW, 124.18) LCMS (EI) m/e 125 (M++H).

Provenance & Evidence