Intramolecular cyclization of 2-hydroxycinnamaldehydes

The effect of substituents on the intramolecular cyclization of 2-hydroxycinnamaldehydes was studied. It was established that aldehydes that contain bulky groups in the side chain and in the 3 position of the benzene ring are readily converted to intramolecular hemiacetals or bimolecular acetals either spontaneously at the moment of isolation or in solutions in DMF or DMSO, as well as on heating. An increase in the lability of the phenolic proton favors the cyclization.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 460–465, April, 1988.