Abstract α-Chamigren-3-one (+)-8 bearing an axial CI-atom at C (8) exists as a largely dominant conformer with Me—C (5) at the envelope-shaped enone ring pointing away from CI ax− C (8) at the cyclohexane ring (= B) in the 'normal'chair conformation, as shown by 1 H- NMR. In contrast, the α-chamigren-3-ols (+)-9 and (+)-10, obtained from hydride reduction of (+)-8, show a temperature-dependent equilibrium of conformers where the major ...
![(+)-(6S,8S,9S)-9-bromo-8-chloro-1,5,5,9-tetramethylspiro[5.5]undec-1-en-3-one Structure](https://image.chemsrc.com/caspic/345/73465-61-9.png)
![(6S)-5,5,9-trimethyl-1-methylidenespiro[5.5]undec-9-en-3-one Structure](https://image.chemsrc.com/caspic/183/61661-48-1.png)
![Spiro[5.5]undecan-3-ol,2,9-dibromo-8-chloro- 1,1,9-trimethyl-5-methylene-,(2S,3R,6S,8S,- 9S)- Structure](https://image.chemsrc.com/caspic/026/73494-22-1.png)