Simple and efficient routes to the natural alkaloid Cerpegin and new analogues are described herein. In a first approach, we extend the scope of a one pot three steps reaction, which permits the synthesis of new analogues of Cerpegin, substituted in different ways. In a second line of approach, we present an unprecedented synthesis of Cerpegin and analogues where methylfuranones are condensed with
A new pyridone alkaloid, cerpegin, was synthesized in five steps starting from the Michael reaction between phenylthioacetonitrile and 2-methoxycarbonyl-4-methyl-2-penten-4-olide. Catalytic hydrogenation of a nitrile group in the presence of a conjugated carbon-carbon double bond was performed by addition of 1 eq of concentrated HCl.
Cerpegin (1), a new pyridone alkaloid, was synthesized starting from the Michael reaction of phenylthioacetonitrile (2) and 2-methoxycarbonyl-4, 4-dimethyl-2-buten-4-olide (3) in five steps. Catalytic hydrogenation of a nitrile group in the presence of a conjugated carbon-carbon double bond was performed by addition of 1 eq of conc. HCl.
Cerpegin 1 was synthesized in a one-pot reaction at room temperature catalysed by cesium carbonate with an overall of 75% yield. 3-Hydroxy-3-methyl-2-butanone 2 reacted with diethyl malonate 3 to give 2-ethoxycarbonyl-3,4,4-trimethyl-2-buten-4-olide 4. Then 4 with s-triazine gave to 1,1-dimethylfuro[3,4-c]pyridine-3,4(1H, 5H)-dione5 and which was alkylated with methyliodide to cerpegin.