Studies on dihydropyridine derivatives-I

Umsetzung von (Z/E)‐1‐Aryl‐4‐arylmethylen‐pyrrolidin‐2,3,5‐trionen mit Enaminocarbonylverbindungen

“…Weitere Vertreter gieser Substanzklasse (7 ac) konnten unter obigen Reaktionsbedingungen bei der Umsetzung einer doppelten molaren Menge der 2-Alkylamino-N-(4-methylphenyl)-maleinimide mit Aldehyden entstehen. = 20,7;27,l;28,4 (CH,); 32,O (C(CH3),); 41, 8;48,9 (CH,);106,4;121,3;122,7;126,5;129,O;129,3;129,7;130,6;131,3;135,O;5 8 ,l ;138,4;144,9;147,7;15G,8 (454,9) 6333 5 4 7 6,32 3305 (NH); 3455 cmn-l (OH); lH-NMR (DMSO-d,): 6 = 1,23 (t, 3H, CH,; J = 7 Hz); 2,59 (5, M-H,O, 30%), 445…”

Enzymatic Tandem Approach to Knoevenagel Condensation of Acetaldehyde with Acidic Methylene Compounds in Organic Media

“…Knoevenagel condensation is one of the most important carbon–carbon bond‐forming reactions, used in the synthesis of chemically and pharmaceutically relevant compounds The Knoevenagel reaction products are also useful intermediates for further transformations, such as oxidative coupling reaction, Nazarov cyclization, Diels–Alder and Michael additions . This atom‐efficient reaction has been used to synthesize some interesting molecules, such as 4,7‐dihydroisoxazolo[5,4‐ b ]pyridines, coumarins, indanones, indenes, stilbenes, and azepinones . Generally, Knoevenagel condensations can be carried out in the presence of bases, Lewis acids, zeolites, clays, ionic liquids, or amino acids .…”