• Title/Summary/Keyword: Stobbe condensation

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Observations on Fragmentation Pathway of Farinomalein and its Isomers by Structural Investigation Using LC-MS/MS

  • Firke, Narayan P.;Markandeya, Anil G.;Deshmukh, Rajendra S. Konde;Pingale, Shirish S.
    • Mass Spectrometry Letters
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    • v.9 no.1
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    • pp.37-40
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    • 2018
  • Farinomalein is a maleimide-bearing compound well known for its anti-fungal activity. In the present study, synthesis of farinomalein is achieved via Stobbe condensation followed by Haval-Argade contrathermodynamic rearrangement. Kinetically driven Stobbe condensation followed by condensation with beta-alanine reveals formation of two isomers of farinomalein. This article describes application of LC-MS/MS in structure elucidation of farinomalein 1 and its isomers 2 and 3 encountered in its synthesis. The proposed distinct fragmentation pathway is supported by rational organic reaction mechanism. These fragmentation pathways are significant for analytical method development of farinomalein in near future. The structures of farinomalein 1 and its isomers 2 and 3 have been assigned undisputedly.

Synthesis and Characterization of New Polyesters Having Unsaturated Groups from Bis [4-(alkyloxy)benzilidene]succinic Anhydride (Bis[4-(alkyloxy)benzilidene]succinic anhydride로부터 유도된 불포화기를 가지는 새로운 폴리에스터의 합성)

  • 김용석;진왕철;정진철
    • Polymer(Korea)
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    • v.26 no.4
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    • pp.439-444
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    • 2002
  • Several monomeric benzilidene anhydrides (2a~d) haying n-alkyloxy groups with various n-alkyl chain lengths were prepared by Stobbe condensation of diethyl succinate with 4-(n-alkyloxy)benzaldehyde (1a,b) followed by hydrolysis by the succinates and cyclodehydration of the benzilidenated succinic acids. Configurational isomerism of the monomer was investigated by spectroscopic means. It was found that monomers (2a~d) exist in (Z,Z)-isomeric structure. Polymerization was carried out in bulk at 150~$210^{\circ}C$ range in nitrogen flow. The chemical structure and thermal properties of the polymers were characterized by spectroscopic means, TGA and DSC. Their properties highly depended on their chemical structures in accordance with a side chain length.