A novel rearrangement of 10-alkyl-9-aryl-lO-thiaanthacenes is described. S-Mesityl-10- methyl-10-thiaanthacene (sa) generated by proton abstraction of 9-mesityl-10- methylthioxanthenium perchlorate (7a) with sodium hydride in THF underwent thermal rearrangement to afford 3-methyl-9-mesitylthioxanthene (Sa). Similarly, the 9-bulky aryl group substituted 10-alkyl-10-thiaanthracenes 7b-f were decomposed thermally to give ...
