Novel intramolecular cyclization of 2-(buta-1,3-dienyl)-3-methylpyrazines and 3-(buta-1,3-dienyl)-4-methyl-1,2,5-oxadiazoles into 5H-cycloheptapyrazines and 4H-cyclohepta-1,2,5-oxadiazoles
作者:Masakatsu Matsumoto、Naoyuki Hoshiya、Ryo Isobe、Yukie Watanabe、Nobuko Watanabe
DOI:10.1016/j.tetlet.2004.03.123
日期:2004.5
3-dienyl)-3-methylpyrazines (5) and 3-(buta-1,3-dienyl)-4-methyl-1,2,5-oxadiazoles (10) were synthesized starting from base-induced reaction of 2,3-dimethylpyrazine or 3,4-dimethyl-1,2,5-oxadiazole with α,β-unsaturated carbonyls. The thus obtained heteroaromatics bearing a butadienyl moiety and a methyl at the adjacent position underwent intramolecular cyclization by the action of LDA to give the corresponding
从碱开始合成2-(Buta-1,3-二烯基)-3-甲基吡嗪(5)和3-(buta-1,3-二烯基)-4-甲基-1,2,5-恶二唑(10)诱导的2,3-二甲基吡嗪或3,4-二甲基-1,2,5-恶二唑与α,β-不饱和羰基的反应。如此获得的在相邻位置带有丁二烯基部分和甲基的杂芳族化合物通过LDA的作用进行分子内环化,得到相应的杂芳族化合物,该杂芳族化合物与七元环[ 7(8)]和[ 11(12)]稠合。高产。