1H and 13C NMR Studies of conformational substituent effect in 4- and 5-monosubstituted derivatives of benzocycloheptene
作者:D. Ménard、M. St-Jacques
DOI:10.1016/s0040-4020(01)91866-6
日期:1983.1
Values of-ΔG° for the axial ⇌ equatorial conformational equilibrium of the chair form of 5-substituted (2–8) and 4-substituted (9–14) derivatives of bezocycloheptene were measured from their 1H and/or 13C NMR spectra recorded under conditions of slow exchange (T < 80°C). Strikingly different conformational substituent effects are noted in each series of compounds. The results are compared with equivalent
苯环庚烯的5-取代(2-8)和4-取代(9-14)衍生物的椅子形式的轴向赤道构象平衡的-ΔG°值是通过其1 H和/或13 C NMR光谱测量的在缓慢交换条件下(T <80°C)记录。在每个系列的化合物中都发现了截然不同的构象取代基效应。将结果与发布的类似六元环导数的等效能量参数进行比较,并根据空间和静电相互作用进行解释。测量了对13 C NMR化学位移的取代基影响,并将其与环己烷环报道的取代基进行了比较。