Ring-transformations of pyrimidines by intramolecular diels-alder reactions. Synthesis of annelated fyridines
作者:A.E. Frissen、A.T.M. Marcelis、H.C. Van Der Plas
DOI:10.1016/0040-4020(89)80111-5
日期:1989.1
Pyrimidines carrying an ω-alkyne side-chain -XCH2CH2CCH (X=O,N,S,SO,SO2) at the 2 or 5 position undergo intramolecularinverseelectrondemandDiels-Alderreactions across the C-2 and C-5 positions; elimination of hydrogen (or alkyl) cyanide from the intermediate adducts leads to condensed pyridines. The influence of the hetero atom (X) in the dienophilic side-chain and that of substituents in the