The Hofmann-like fragmentation induced by n-acylation of 1-methyl-1-AZA-4-cyclanones and its use in the synthesis of 2-AZA-hydrindanones and 2-AZA-decalones
作者:Jean Lévy、Jean-Yves Laronze、Janos-Sapi
DOI:10.1016/0040-4039(88)85147-5
日期:1988.1
N-methyl-piperidone was fragmented to the vinylketonic acrylamide by successive treatment with acryloyl chloride and Hunig's base. The 2-azahydrindandione resulted from the cyclization of 9a in the form of its enol dimethylterbutyl ether. N-methyl-azepinone was transformed in a similar way to the two epimeric 2-azadecalindiones + in four steps only.
B-ring were synthesized using the “nitrousaciddeamination” of indolenines as the key step. Thus, indolenines 13 and 15 were prepared by Fischer synthesis from the corresponding bicyclic ketolactams 6 and 12, respectively, and further transformed into the related hexahydrodibenzofurans. Ketolactam 6 was obtained from 3-nitromethylcyclohexanone using classical chemistry, whereas 12 was built up by fragmentation