97856-60-5

Upstream product

• 37746-78-4 4-bromo-trans-crotonic acid ethyl ester 
• 603-32-7 triphenyl-arsane 

Downstream Products

• 97856-61-6 3-Ethoxycarbonylallylidenetriphenylarsorane 
• 39806-17-2 Ethyl 5-(4-chlorophenyl)-2,4-pentadienoate 
• 16913-49-8 5-<4-(dimethylamino)phenyl>-2,4-pentadienoic acid ethyl ester 
• 371111-51-2 5-(4-chloro-phenyl)-pentanoic acid ethyl ester 
• 711014-67-4 (2E,4E)-5-(4-aminophenyl)penta-2,4-dienoic acid ethyl ester 
• 711014-68-5 (2E,4E)-5-[4-(4-Methoxy-benzenesulfonylamino)-phenyl]-penta-2,4-dienoic acid ethyl ester 
• 39806-23-0 ethyl (2E,4E,6E)-7-phenyl-2,4,6-heptatrienoate 
• 97856-56-9 ethyl (2E)-4-cyclohexylidenebut-2-enoate 
• 16913-46-5 (2E,4E)-5-(4-nitro-phenyl)-penta-2,4-dienoic acid ethyl ester 

Relevant academic research and scientific papers

Occurrence of an elongated p-oxo ketene intermediate in the dissociative alkaline hydrolysis of aryl (2E,4E)-5-(4'-hydroxyphenyl)pentadienoates

The alkaline hydrolysis of title esters possessing acidic leaving groups follows an E1cB mechanism involving the participation of an 'extra extended' p-oxo ketene intermediate. For the hydrolysis of the 2,4-dinitrophenyl ester kinetic data, activation parameters and trapping of the intermediate clearly indicate that the dissociative pathway carries the reaction flux. Break in the Bronsted plot of the apparent second-order rate constants versus the pK(a) of the leaving group suggests that the reaction mechanism changes from E1cB to B(Ac)2 for esters having pK(a) higher than about 6.