E,4E ) 2,4 dimethyl 5 ( p nitrophenyl)penta 2,4 dienoic acid and (2 E,4E ) 2,4 dimethyl 5 ( m nitrophenyl)penta 2,4 dienoic acid,potential antibiotics,were synthesized through aldol condensation and Perkin reaction in two steps,( 2E,4E ) 2,4 dimethyl 5 ( m nitrophenyl)penta 2,4 dienoic acid is a new compound and its structure was confirmed by IR and 1HNMR spectral analysis.

Using substituted benzaldehyde as starting materials, 2-methyl-3- (4 - nitrophenyl) allyl-triph- enylphosphonium bromide and 2-methyl-3-(3-nitrophenyl ) allyl-triphenylphosphonium bromide, intermedi-ates of potential antibiotics, were synthesized through Aldol condensation, reduction, bromization, etc.