Orthothioesters and 1,1‐bis‐(ethylthio)‐1‐alkenes (thioacetals of ketenes)

A number of ethyl orthothioesters has been prepared by refluxing acid chlorides with ethanethiol and zinc chloride. The substances very easily lose one mole of ethanethiol by distillation in the presence of traces of acids, affording the thioacetals of substituted ketenes VII. The structure of the latter compounds follows from the hydrolysis of their sulphones VIII into the next lower aldehydes IX and bis (ethanesulphonyl) methane X. It is pointed out, that interesting reactions can be carried out by making use of various methods for the introduction and elimination of thioether groups (see reaction schemes on pages 5 and 6).