Abstract: New 2,9-dioxatricyclo[4,3,1,0.sup.3,7 ] decane derivatives are disclosed which are substituted by an amino methyl group in the C.sub.3 position, and which exhibit sedative, especially sleep improving properties, and which have the formula ##STR1## wherein R.sub.1 represents an amino groupone of R.sub.2 and R.sub.3 is hydrogen and the other represents hydroxy acyloxy or carbamyloxy or R.sub.2 and R.sub.3 jointly represent oxygenone of R.sub.4 and R.sub.5 is hydrogen and the other represents alkyloxy or aralkyloxy y and y' each represent hydrogen or jointly form a bond and their pharmacologically acceptable salts, as well as pharmaceutical formulations thereof.