Thermal reaction of alkynyl propargyl sulfoxides 1 afforded novel highly reactive (α-ketovinyl)thioketenes 3. Trapping experiments using a primary or secondaryamine, formation of furanophane 4, through head-to-tail type dimerization, as well as direct observation using 1H NMR elucidated the generation pathway of 3 through sequential [2,3]/[3,3] sigmatropicrearrangement.
炔基炔丙基亚砜1的热反应提供了新型的高反应性(α-酮乙烯基)硫代乙烯酮3。使用伯胺或仲胺进行捕获实验,通过头尾型二聚形成呋喃喃酮4以及使用1 H NMR进行直接观察阐明了3通过顺序[2,3] / [3,3]的生成途径σ重排。