Tetrahedron

Intramolecular Diels-Alder reactions of 2-(alkynyl) pyrimidines and 2-(alkynyl) pyridines

AE Frissen, ATM Marcelis, G Geurtsen, DA De Bie…

Index: Frissen, A. E.; Marcelis, A. T. M.; Geurtsen, G.; Bie, D. A. de; Plas, H. C. van der Tetrahedron, 1989 , vol. 45, # 16 p. 5151 - 5162

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Citation Number: 27

Abstract

Pyrimidines 3, 7 and 13 carrying an ω-alkynyl side-chain-CR2 (CH2) nCH2C CH (R= H, CN; n= 1, 2) at the 2-position undergo intramolecular inverse electron demand Diels-Alder reactions across the C-2 and C-5 positions. Loss of hydrogen cyanide, caused by a retro- Diels-Alder reaction, from the intermediate cycloadducts leads to annelated pyridines 5, 9 and 15, respectively. Similarly, from the nitropyridines 16 the 2, 3-dihydronitro-1H-indenes ...