The present invention relates to urethanes and the thio and dithio analogues thereof of general formula 1 wherein m, n, A, X, Y and R1 to R8 are defined as in claim 1, the enantiomers, diastereomers and the salts thereof, particularly the physiologically acceptable acid addition salts thereof which have valuable properties, particularly an inhibitory effect on cholesterol biosynthesis, pharmaceutical compositions containing these compounds, their use and processes for preparing them.