Résumé : The alcohols 1 to 4 were prepared with good to excellent yields. Their 1H and 13C N.M.R. spectra were recorded at different temperatures. For 1, 2 and 3, the conformational barriers corresponding to the C9'‐C1 rotation are close to 11, 14.5 and 19 KcalM−1, respectively. Copyright © 1985 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim