摘要 : Abstract 3‐(2,2‐dichloroacetyl)‐2H‐Chromen‐2‐ones were prepared by treating salicyl N‐tosylhydrazones with ethyl 4,4,4‐trichloro‐3‐oxobutanoate in presence of catalytic amount of La(OTf)3 and RuCl3???3H2O for the first t... 展开 Abstract 3‐(2,2‐dichloroacetyl)‐2H‐Chromen‐2‐ones were prepared by treating salicyl N‐tosylhydrazones with ethyl 4,4,4‐trichloro‐3‐oxobutanoate in presence of catalytic amount of La(OTf)3 and RuCl3???3H2O for the first time. The chromenones were formed through C‐C, C‐O bond formations, detosylation and more importantly dechlorination protocol. One of the compound 3‐(2,2‐dichloroacetyl)‐6‐methyl‐2H‐chromen‐2‐one structure was confirmed by single‐crystal X‐ray analysis. Further, salicyl N‐tosylhydrazones when treated with dimethyl (1‐diazo‐2‐oxopropyl)‐phosphonate (Bestmann‐Ohira reagent) in presence of K2CO3 and RuCl3???3H2O provided (E)‐N′‐(2‐hydroxybenzylidene)‐N,4‐dimethylbenzenesulfono hydrazide. 收起