ChemInform Abstract: SYNTHESIS OF 3‐BENZYL‐4‐CHROMONES AND 3‐BENZYL‐1‐THIO‐4‐CHROMONES

Abstract

In Gegenwart von Phosphorsäure kondensieren die Chromanone und Thiochromanone (I) mit den Benzaldehyden (II) zu den Benzylidenchromanonen (III), die thermisch in Gegenwart einer sehr geringen Menge Piperidin zu den Benzylchromonen (IV) isomerisieren.

Structural studies of seven homoisoflavonoids, six thiohomoisoflavonoids, and four structurally related compounds

“…Elemental analyses performed at the Organic Chemistry Department of Eötvös Loránd University (Budapest, Hungary) were undertaken on IIa, IVc, V, and VIII and were within 0.4% of the calculated values. The remaining compounds have been described previously (I-IV: [12,17,18]; VI: [19], VII: [15]) and had melting points in accord with the literature values. The structures of the investigated compounds and their numbering used are shown in Fig.…”

Facile Condensation of Aromatic Aldehydes with Chroman‐4‐ones and 1‐Thiochroman‐4‐ones Catalysed by Amberlyst‐15 under Microwave Irradiation Condition

“…In a previous method for synthesis of compounds 2, their isomerisation to corresponding endocyclic compounds [i.e., to 3-(arylmethyl)chromones or 3-(arylmethyl)thiochromones] were reported 18 . In the present method no trace of such isomerisation was observed (3-(arylmethyl)chromones and 3-(arylmethyl)thiochromones are known to give a two-proton singlet around δ 3.85 and 4.00, respectively, for their methylene protons 18 . However, any product giving such spectral features could not be isolated by us).…”

Synthesis of heterocyclic compounds by the reactions of exocyclic α,β‐unsaturated ketones

“…Inorg a n i c bases have also been used as catalysts for this purpose [47][48][49]. In our previous studies [50][51][52][53][54], piperidine proved to be a convenient catalyst for the synthesis of compounds 4 -7. All these exocyclic α,β-unsaturated ketones (1 -7) synthesized either by acid-or base-catalyzed condensation of the appropriate cyclic ketone and aromatic aldehyde were (E)-diastereomers [55].…”