ISSN:
0170-2041
Keywords:
Azacoumestans
;
Benzofuranes
;
Heck reaction
;
2(1H)-Quinolones, 4-hydroxy-
;
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Palladium-Catalyzed Ring Closure Reactions to Benzofuranes: A New and Effective Approach to AzacoumestrolsAzacoumestans (benzofuro[3,2-c]quinolinones) 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.
Additional Material:
8 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/jlac.1990199001101
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