There are presented compounds of the formula ##STR00001## wherein R.sup.6 and R.sup.7 is ##STR00002## R.sup.4 and R.sup.5 or R.sup.5 and R.sup.6 together with the carbon atoms to which they are attached, form a ring as defined in the description and X.sup.1, X.sup.2, Y.sup.1 to Y.sup.4, R.sup.1 to R.sup.13 and n are as specified in the description, and to all enantiomers and pharmaceutically acceptable salts and/or esters thereof. The invention further relates to pharmaceutical compositions containing such compounds, to a process for their preparation and to their use for the treatment and/or prevention of diseases which are modulated by PPAR.delta. and/or PPAR.alpha. agonists.