Facile and general method for preparation of (E)‐4‐hydroxy‐2‐alkenals

A facile one-pot synthesis of (E)-4-hydroxy-2-alkenals such as (E)-4-hydroxy-2-nonenal, (E)-4-hydroxy-2-heptenal, and (E)-4-hydroxy-2-hexenal was achieved from the corresponding (2E,4E)-2,4-alkadienals by reduction-oxygenation with molecular oxygen and triethylsilane in the presence of cobalt(II) porphyrin as a catalyst followed by treatment with trimethylphosphite.