A new direction in the alkylation of 5-acetyl-2-amino-6-methyl-4-phenyl-4H-pyran-3-carbonitrile with active methylene reagents

In this paper, we report a new synthesis route to 4H-pyran derivatives and a plausible reaction mechanism. The interaction of 5-acetyl-2-amino-6-methyl-4-phenyl-4H-pyran-3-carbonitrile with different active methylene reagents gives rise to the cleavage and subsequent recyclization of the pyran ring to afford the corresponding 4H-pyran derivatives. © 2018 The Chemical Society Located in Taipei & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim