B. Raju, G. Saidachary, J. A. Kumar
Aug 5, 2012
Citations
0
Influential Citations
23
Citations
Journal
Tetrahedron
Abstract
Abstract Wittig homologation of 2-(chloromethyl)-2 H -chromen-2-ol derivatives 2a – t with (ethoxycarbonylmethylene)triphenylphosphorane provided the 2-oxoethylidene-2,3-dihydrobenzoxepine-4-carboxy-lates 3a – t with Z ( cis ) selectivity. Various basic catalysts were studied for the reaction of 2-(chloromethyl)-2 H -chromen-2-ol 2a with the combination of Wittig reagent to provide compound 3b . The reaction of 2-(chloromethyl)-2 H -chromen-2-ol 2a with other Wittig reagents, such as methylene(triphenylene)phosphorane and (1-ethoxycarbonylethylidene)triphenylphosphorane provided ketone derivative 4a rather 2-oxoethylidene derivative 3b . The ketone derivative 4a was reacted with Wittig reagent (ethoxycarbonylmethylene)triphenylphosphorane to give 2,3-dihydrobenzoxepine-4-carboxylate 3b . The present approach is novel, straight forward and being reported for the first time.