Synthesis of Hydroxypyrrolone Carboxamides Employing Selectfluor.
Reaction of pyrrole-2-carboxamides with Selectfluor in MeCN/water (4:1) affords 2-hydroxy-5-oxopyrrole-2-carboxamides in yields of up to 80 %. A variety of sensitive functional groups is tolerated, among them aldehydes and alkynes. The new method also works in the presence of allyl groups and appears to be superior to the use of singlet oxygen. Reaction of the monobrominated dihydropyrrolo[1,2-a]pyrazinone mukanadin C and its nonbrominated analogue afforded bicyclic hydroxypyrrolones. These compounds are interesting as they constitute a partial structure of the marine natural product oxocyclostylidol.
Institute of Organic Chemistry, Technical University Braunschweig, Hagenring 30, 38106 Braunschweig (Germany).
Tim Carlo
TC
Allmann
Institute of Organic Chemistry, Technical University Braunschweig, Hagenring 30, 38106 Braunschweig (Germany).
Rares-Petru
RP
Moldovan
Institute of Inorganic and Analytical Chemistry, Technical University Braunschweig.
Peter G
PG
Jones
Institute of Organic Chemistry, Technical University Braunschweig, Hagenring 30, 38106 Braunschweig (Germany). th.lindel@tu-braunschweig.de.
Thomas
T
Lindel
D002384:Catalysis; D003979:Diazonium Compounds / Q000737:chemistry*; D006842:Hydrocarbons, Brominated / Q000737:chemistry*; D015394:Molecular Structure; D011719:Pyrazines / Q000138:chemical synthesis* / Q000737:chemistry*; D011758:Pyrroles / Q000138:chemical synthesis* / Q000737:chemistry*; D013237:Stereoisomerism
D003979:Diazonium Compounds; D006842:Hydrocarbons, Brominated; D011719:Pyrazines; D011758:Pyrroles; C000608457:dihydropyrrolo(1,2-a)pyrazinone; C408750:selectfluor
Selectfluor; heterocycles; marine natural products; oxidation; pyrroles