Intramolecular cyclization reactions of pyrimidinium cations

…, G Geurtsen, ATM Marcelis, HC Van der Plas

Index: Frissen, A. E.; Geurtsen, G.; Marcelis, A. T. M.; Plas, H. C. van der Tetrahedron, 1990 , vol. 46, # 2 p. 595 - 606

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Citation Number: 9

Abstract

N-alkylpyrimidinium cations carrying a dienophilic side-chain at the 2-or 5-position undergo intramolecular inverse electron demand Diels-Alder reactions into the corresponding annelated pyridine derivatives under considerably milder conditions than the corresponding neutral pyrimidines. Protonation of the pyrimidine ring also facilitates the intramolecular Diels-Alder reaction. Protonation of less activated pyrimidines leads, however, to products ...