Regioselective Condensation of Alkylidenephosphoranes with Bifunctionalized Compounds: New Approach to the Synthesis of Fused<i>O</i>- and<i>N</i>-Heterocycles
作者:Wafaa M. Abdou、Neven A. F. Ganoub、Amin F. M. Fahmy、Abeer A. M. Shaddy
DOI:10.1080/104265090921092
日期:2005.10
A series of fused pyran- (similar to 40% yield) and furan- (similar to 20% yield) derivatives were regioselectively prepared from the reactions of 5,6-difur-2'y1-3-oxo-2,3-dihydropyridazin-4-carbonitrile with ester- and keto phosphorus ylides, whereas new ylides were obtained, in addition to fused furans, in almost equal yields (33%) from the reaction of the same substrate with cyanomethylene(triphenyl)phosphorane. However application of such Wittig reagents on 2[(benzylidene)amino]-benzonitrile afforded, in all cases, 4-hydroxyquinalines in a similar to 42% yield as major products. Moreover; 2-[(triphenylphosphoranylidene)amino] benzonitrile, with the corresponding alkene, was also isolated a side products.