ChemInform Abstract: 2‐HYDROXY‐1,3‐INDANDIONE DERIVATIVES. II. CONDENSATION PRODUCTS OF NINHYDRINE E WITH POLYPHENOLS AND THEIR O‐METHYLATED DERIVATIVES

Abstract

Polyphenole und Polyphenolether vom Typ (I) reagieren beim Erhitzen ,mit äquimolaren Mengen Ninhydrin (II) in Essigsäure zu Derivaten des Typs (III), wobei die Substitution selektiv in ortho‐ Stellung erfolgt falls diese Stellung nicht chelatisierbar ist; neben (IIIa) bzw. (IIIb) entstehen auch die 3,4‐Dihydroxy‐ bzw. 3‐Methoxy‐4‐hydroxy‐Isomeren (7 bzw. 5% Ausb.).

The Chemistry of Vicinal Polycarbonyl Compounds

“…Analogous behavior has also been reported for phenols 134 with C-C bond formation ortho to a hydroxyl group followed by equilibrium between phenols (128) and cyclic hemiketals (129).…”

Intramolecular Reversible Addition Reactions to the C=O Group

“…The introduction of substituents R 1 and R4 into molecules of ninhydrin condensation products with polyphenols shifts the equilibrium (125A) ~ (125B) in favor of the cyclic isomer [428]. In an ethanolic solution of 3-acetyl-2-(2-hydroxy-3-acetylphenylamino)-5-methoxy-I,4-benzoquinone (126, Rl = Me, R2 = 3-MeCO) the cyclic form predominates but in solvents of lower polarity the equilibrium is shifted toward the open form.…”

One-Pot Multi Component Synthesis of Xanthenediones and Acridinediones at Room Temperature

“…Xanthene-based compounds are important because of their use in medicine as they possess antimicrobial activities 2 . These compounds have also been investigated for agricultural bactericidal activity 2a , photo dynamic therapy, antiinflammatory effects 3 and antiviral activity 4 . In particular, octahydroxanthene constitutes a structural unit in several natural products 5 and they are valuable synthons because of the inherent reactivity of the in built pyran ring 6 .…”