Proscillaridin a derivs

New derivs. of Proscillaridin A of general formula I and their prepn. where R', R2 and R3 = H or acyl up to C4, at least one being acyl, pref. acetyl Cardiac stimulants of increased oral effectiveness relative to proscillaridin A. (II). By treatment of II with a reactive acyl cpd. in known manner e.g. with acylhalides or anhydrides with or without a solvent and pref. in the presence of an acid binding agent at 0-150 deg. depending on the degree of acylation and the reaction time, e.g. the triacetyl deriv. is obtained after 3 days at 28 deg. or 4 hrs. at 110 deg.; the diacetyl deriv. may be obtained at -15 deg. The products contain 1-3 acyl groups on the rhamnose moiety.