Acid-catalyzed double-bond isomerization of 8a-substituted 5,5-dimethyl-3,5,6,7,8,8a-hexahydronaphthalen-2(1H)-ones

Publication Type

Journal contribution

Authors

Kato, M.; Vogler, B.; Yoshikoshi, A.

Year of publication

1991

Published in

J. Chem. Res., Synop.

Band/Volume

5/

Page (from - to)

114-5

The acid-catalyzed isomerization of title compds., e.g., I (R = CO2Me, CH2OMe, Ac, Me, CH:CH2), was studied. Deconjugated octalones possessing an oxygenated substituent at C-8a provided good yields of cis-conjugated octalones II, stereoselectively, whereas compds. I having an alkyl angular substituent gave mixts. of cis- and trans-IIin almost equal ratios. Stereochem.assignment of the conjugated octalones obtained was established by comparison of allylic coupling consts. (J3,4a) in their 1H NMR spectra. The conformation of cis-II was deduced to be steroidal on the basis of the small magnitude of J3,4a (<1 Hz).