作者:Walter Thommen、Herv� Pamingle、Karl H. Schulte-Elte
DOI:10.1002/hlca.19890720623
日期:1989.9.20
Diels-Alder reactions of 1-, 2-, and 5-methylcyclopenta-1,3-dienes (i–iii, respectively) at 20° was shown by GLC analysis to consist of at least 10 components (Table 1). The structures of the six major isomers 1–6, representing 96% of the total mixture, were established by 1H- and 13C-NMR spectroscopy. Whereas on heating up to 110° the proportions of 1, 2, 4, and 6 remain nearly unaffected (±2 %), the dimers
1-,2-和5-甲基环戊-1,3-二烯的Diels - Alder反应产生的异构二甲基-内-三环[5.2.1.0 2,6 ] deca-3,8-二烯(A)混合物GLC分析显示,在20°时(分别为i – iii)至少包含10个成分(表1)。六个主要异构体的结构1 - 6占总混合物的96%,中,通过建立1 H-和13 C-NMR光谱。而在加热到110℃的比例1,2,4,和6几乎保持不受影响(±2%),二聚体3和5分别在20°时以22%和24%的产率形成,通过[3,3]-σ重排可逆地在70°以上异构化并在30°C时达到平衡。大约110° 10:1的比例。