First thia-Diels-Alder reactions of thiochalcones with 1,4-quinones.

ABSTRACT: Aryl and hetaryl thiochalcones react smoothly with 1,4-quinones in THF solution at 60 °C yielding the corresponding fused 4H-thiopyrans after spontaneous dehydrogenation of the initially formed [4 + 2] cycloadducts. In general, the yields of the isolated products were high. With 5-chloro-10-hydroxy-1,4-anthraquinone, the thia-Diels-Alder reaction occurred with complete regioselectivity. In the case of the reaction of vitamin K₃ (menadione) with diphenylthiochalcone, the initial cycloadduct was isolated in 37% yield.

SUBMITTER: Mloston G 

PROVIDER: S-EPMC6071716 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature