6,11-Dihydrodibenzo-[b. e.]-thiepin-11-one-3-aldehyde and 3-acetal derivatives

A compound selected from the group of those represented by the formulas ##STR5## wherein R represents hydrogen or methyl, and each of R.sup.1 and R.sup.2, which can be the same or different, represents a lower alkyl group of 1 to 6 carbon atoms, or together represent a lower alkylene radical of 2 to 6 carbon atoms, provided that when R is methyl, the compounds are (dl) mixtures, and when R.sup.1 and R.sup.2 are different, the compounds are pairs of diasteroisomers and each diasteroisomeric isomer is a (dl) mixture.