After the conformation I was clarified to 5a,lOa-cis-solidagolactones by lH NMR measurement with Eu(dpm)3 and chemical transformations, the CD homoallylic benzoate chirality method was applied to the homoallylic alcohol system of solidagolactone IV (la) for a chiroptical determination of the absolute configuration. The result agreed with t.6 absolute configuration elucidated by X-ray analysis, indicating the usefulness of the CD method. The allylic benzoate chirality method, a CD exciton chirality method', has been successfully applied for determining absolute configurations of allylic alcohols2. Naya et 02.~ determined the absolute structure of the insect sesterterpene, 5-hydroxyfloridenol, in which the 5-OH functioned as both allylic and homoallylic alcohols. They observed, therefore, a positive Cotton effect composed of both allylic and homoallylic benzoate chiralities in the CD of 5-p-bromobenzoate derivative of the sesterterpene. This suggested that the homoallylic benzoate chirality may be arised from the same chiral exciton coupling mechanismas in thecaseof allylic benzoate chirality. In the present case, a 5a,lOcc-cis-solidagolactone, solidagolactone IV (la) (clerodane diterpene) which was isolated from SoZidago aZtis.stia L. as a piscicidal