78932-06-6

Upstream product

• 50838-22-7 1-crotonoylpiperidine 
• 104-87-0 4-methyl-benzaldehyde 
• 92356-72-4 methyl (2E,4E)-5-((p-methyl)phenyl)penta-2,4-dienoate 
• 15542-36-6 (2E,4E)-5-p-Tolyl-penta-2,4-dienoic acid 
• 110-89-4 piperidine 
• 443360-64-3 (2E,4E)-5-p-Tolyl-penta-2,4-dienoyl chloride 

Relevant academic research and scientific papers

Synthetic and spectroscopic studies of structural analogs of piper amides - The 5-aryl-2E,4E-pentadienamides

The methyl esters and piperidides of fourteen 5-aryl-2E,4E-pentadienoic acids have been synthesized starting from the corresponding aryl aldehydes.

Substituent Effects on Carbon-13 NMR Chemical Shifts of Side-chain Carbons in 5-Aryl-2E,4E-pentadienoic Acid Derivatives

The 13C NMR spectra of two series of 5-aryl-2E,4E-pentadienoic acid derivatives, viz. the methyl esters and piperidides have been determined.The chemical shifts of C-2 and C-4 show very good correlations with the Hammett ?+-constants for all the substituents investigated, except for the para-nitro group which is capable of excerting a strong -R effect.A possible explanation for this has been advanced.Hammett correlations between substituents and the chemical shifts of both C-3 and C-5 carbons using ?0 parameters are less satisfactory.A reverse chemical shift effect has been observed for these two centres.