Abstract: The invention provides novel compounds of the formula: ##STR1## wherein n is 0 to 4, R.sub.1 and R.sub.2, which can be the same or different are H, OH, alkoxy of 1 to 4 carbon atoms, benzyloxy or methoxymethoxy; R.sub.3 is H, OH, halogen, alkoxy of 1 to 4 carbon atoms, benzyloxy, methoxymethoxy, 2,3-dihydroxypropoxy or ##STR2## wherein m is 1 or 2, R.sub.6 and R.sub.7, which can be the same or different are H or an alkyl group of 1 to 4 carbon atoms, or ##STR3## can form an N-containing three-, four-, five- or six-membered heterocyclic ring; R.sub.4 is OH, F, Cl, Br, I, mesyloxy, tosyloxy, alkylcarbonyloxy of 1 to 4 C-atoms, formyloxy or CH.sub.2 R.sub.4 is replaced by CHO; R.sub.5 is H or OH; or R.sub.4 and R.sub.5 together form an --O-- bridge between the carbon atoms to which they are attached, and their non-toxic pharmaceutically acceptable salts and esters and mixtures thereof. Processes for the preparation of these compounds are described, and also novel pharmaceutical compositions containing them.