3-(1,1-Dioxadibenzothien-4-oyl)acrylic acid (1) was condensed with compounds containing active methylene groups under Michael reaction conditions to furnish the Michael adducts (lactones 2a-c, lactams 3a-c, ketones 4a,b). The behavior of these adducts toward the action of hydrazine hydrate were investigated. The compounds were tested for their biological properties.