Reaction of Methyl 4,5-Epoxy-(2E)-pentenoate with Arenes. I. A Facile Synthesis of 4-Aryl-5-hydroxy-(2E)-pentenoate Derivatives.

The reactivity of methyl 4,5-epoxy-(2E)-pentenoate (2) toward various aromatic nucleophiles in the presence of boron trifluoride etherate was examined. When benzene derivatives possessing an electron-donating substituent were employed, meta-substituted benzenes attacked only the 4-position of 2, while ortho- or para-substituted benzenes simultaneously attacked the 4- and 2-positions of 2