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 intramolecular inverse electron demand Diels-Alder reactions 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
嘧啶携带ω-炔侧链-XCH 2 CH 2 CCH(X = O,N,S,SO,SO 2)在2位或5位经历跨越C-分子内逆电子需求狄尔斯-阿尔德反应2和C-5职位;从中间加合物中消除氰化氢(或烷基)会导致吡啶缩合。讨论了双亲性侧链中的杂原子(X)和嘧啶环中的取代基对反应性的影响。