Reactions of 3‐Nitro‐2‐trihalomethyl‐2H‐chromenes with C‐Nucleophiles. Synthesis of 3‐Nitro‐4‐(pyrazol‐4‐yl)‐2‐trihalomethylchromanes.

Abstract

Reactions of 3-Nitro-2-trihalomethyl-2H-chromenes with C-Nucleophiles. Synthesis of 3-Nitro-4-(pyrazol-4-yl)-2-trihalomethylchromanes.-The reaction of 3-nitro-2-trihalomethyl-2H-chromenes (I) with C-nucleophiles (II) or (IV) and the reaction of the resulting products (III) with hydrazine and methyl hydrazine is studied. With exception of (IIId), the heterocyclization does not lead to a change in stereochemistry of the pyran ring. -(KOROTAEV, V. Y.; SOSNOVSKIKH*, V. Y.; KUTYASHEV, I. B.; KODESS, M. I.; Russ. Chem. Bull. 55 (2006) 11, 2020-2031; Gorky Ural State Univ., Ekaterinburg 620083, Russia; Eng.) -M. Bohle 36-123