Various 4- and 4,5-substituted 2,7-di-tert-butylthiepins such as 4-ethoxycarbonyl-(6), 4-formyl- (7), 4-hydroxymethyl- (8), 4-methyl- (12), 4-methy1-5-hydroxymethy1-(13), and 4,5-dimethyl derivatives (16), and so on, were synthesized by functional group transformation and some of their properties were examined.
4,5-Bis(ethoxycarbonyl)-2,7-di-t-butylthiepine and 3,5-bis(ethoxycarbonyl)-2,7-di-t-butylthiepine have been synthesized. Thermal stabilities of these thiepines have been examined and discussed in connection with those of the monocyclic thiepines reported so far.