Synthesis of 3,7-disubstituted hexahydro- and tetrahydro-2H-indazoles from cross-conjugated dienones

Аннотация

The oxidation of 3,7-disubstituted hexahydroindazoles with potassium hexacyanoferrate(III) afforded previously unknown tetrahydro-2H-indazole derivatives. A novel ring contraction reaction leading to 2,3-diazaspiro[4.4]non-3-en-1-one derivatives was discovered. The product structure was proved by NMR spectroscopy, mass spectrometry, and X-ray analysis.