9-Methyl-cis-decalin-1,3-dion: Stereochemische Untersuchungen an 9-Methyl-cis-decalin-Derivaten. 5. Mitteilung über cyclische β-Diketone

The synthesis and the spectral properties of the hitherto unknown 9-methyl-cis-decalin-1,3-dione ( 16 ) are described. The keto-enol equilibrium of 16 in various solvents was determined by NMR. spectroscopy. The configuration and conformation of a large number of intermediates and derivatives were determined.