A convenient synthesis of 4,5-disubstituted 2H-thiopyran 1,1-dioxides is reported through a base induced process starting from eneyne sulfones. Except for strongly electron-withdrawing groups, the reaction tolerated a wide variety of substituents in the two aryl rings. This finding represents a major departure from the behaviour of the corresponding ethers. The reaction most probably proceeds through
据报道,通过从烯炔砜开始的碱诱导过程,可以方便地合成 4,5-二取代的 2H-
噻喃 1,1-二氧化物。除了强吸电子基团外,该反应可以容忍两个芳环中的多种取代基。这一发现代表了与相应醚行为的重大背离。该反应最有可能通过原位生成的 1,3,5-亚
磺酸三烯酯的 6π-电环化进行。