- The Wolff-Kishner Reduction of 2-Acetonyl Pyrazines and Pyridines. A Novel Rearrangement
-
Wolff-Kishner reduction of 1-(6-methylpyrazin-2-yl)-2-propanone leads to the formation of 2-isopropyl-6-methylpyrazine (2a), in addition to the expected 6-methyl-2-n-propylpyrazine.The by-product 2a is suggested to arise via a spirocyclopropylidene aza-anion, which serves as a conduit between the initial less-stable secondary 1-(2-pyrazinyl)-2-propyl carbanion and the more stable primary 2-(2-pyrazinyl)-1-propyl carbanion.Similar results were observed for the 1-(3-methylpyrazin-2-yl) and 1-(6-methylpyridin-2-yl)-2-propanones.The extent of by-product formation diminished in the pyridine ring system.Electrophilic activation of the ring appears essential since the benzene ring analog phenylacetone gave no detectable cumene under identical reaction conditions.
- Paine III, John B.
-
p. 1463 - 1465
(2007/10/02)
-
- Ueber die Synthese von 2,3-Dialkylpyrazinen
-
2,3-Dialkylquinoxalines (4), which are available from the reaction of benzofuroxan (1) with ketones and subsequent reduction of the 2,3-dialkylquinoxaline N,N'-dioxides (3), are converted to 2,3-dialkylpyrazines (6) by oxidation-decarboxylation steps.
- Heyns, Kurt,Behse, Ernst,Francke, Wittko
-
p. 240 - 245
(2007/10/02)
-