SummarySelected hetaryl and aryl thioketones react with acetylenecarboxylates under thermal conditions in the presence of LiClO4 or, alternatively, under high-pressure conditions (5 kbar) at room temperature yielding thiopyran derivatives. The hetero-Diels–Alder reaction occurs in a chemo- and regioselective manner. The initially formed [4 + 2] cycloadducts rearrange via a 1,3-hydrogen shift sequence to give the final products. The latter were smoothly oxidized by treatment with mCPBA to the corresponding sulfones.

ChemInform Abstract (38 refs.).

Thiazole derivatives R 0260 Chemoselectivity of the [2 + 3]-Cycloaddition of Thiocarbonyl Ylides with 5-Benzylidene-3-phenylrhodanine. -The reaction of title ylides, generated in situ from compounds (I), (VI), and (IX), is studied. -(SEYFRIED, M. S.; LINDEN, A.; MLOSTON, G.; HEIMGARTNER*, H.; Pol.

No abstract