β-Aroyl-α-(arylmethylene)propionic Acids

✍ Scribed by Guirguis, Nadia R. ;Boshra, ;Awad, M. ;Saad, Hanaa A.

• Publisher: John Wiley and Sons
• Year: 1986
• Tongue: English
• Weight: 176 KB
• Volume: 1986
• Category: Article
• ISSN: 0947-3440
• DOI: 10.1002/jlac.198619860416

✦ Synopsis

P-Aroyl-a-(ar y1methylen)propionsauren

Kondensation der P-Aroylpropionsauren 2a -d mit Furfural (1) fiihrt zu (E,Z)-Gemischen der Enollactone 3a-d. Die Zuordnung zur (E)oder (2)-Reihe und das Isomerenverhaltnis wurden durch hochaufgeloste 'H-NMR-Spektren bestimmt.

Condensation of aromatic aldehydes with P-aroylpropionic acids gives the en01 lactones of P-aroyl-a-(arylmethy1ene)propionic acids' -3). These enol lactones purified by recrystallization, were assigned to be (E)-configurated without a crucial evidence. We were interested to investigate whether the reaction leads also to the (Z)-enol lactones which were probably lost during thc purification steps described in former publications.

We therefore treated furfural(1) with p-substituted P-benzoylpropionic acids 2a -d in the presence of acetic anhydridelsodium acetate (Perkin conditions) and we obtained isomeric l z # + % 0 ' R (E)-3a-d (Z)-3a-d ; I ' b CH, c OCHB d C1 I A