125879-12-1Relevant articles and documents
Palladium-Catalyzed Ring Closure Reactions to Benzofuranes: A New and Effective Approach to Azacoumestrols
Stadlbauer, Wolfgang,Laschober, Rita,Kappe, Thomas
, p. 531 - 539 (2007/10/02)
Azacoumestans (benzofuroquinolinones) 4 have been synthesized using the following three methods: ring closure of 3-aryl-4-hydroxy-2-quinolones 3a-e by Pd-catalyzed cyclodehydrogenation, ring closure of 3-hydroxy-3-aryl-2,4-quinolinediones 5 by acid-catalyzed cyclodehydratation, or ring closure of 4-aryloxy-3-iodo-quinolones 8, which are obtained by rearrangement of iodonium ylides 7, by palladium-mediated cyclodehydrohalogenation.Only the latter reaction yielded the coumestrol analog dimethoxy derivatives 4c, d, which have been transformed into the hydroxy and acetoxy derivatives 9, 10.