Hetero-Diels-Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles.

ABSTRACT: Selected 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.

SUBMITTER: Mloston G 

PROVIDER: S-EPMC4464410 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature