【摘要】 采用梯度校正的密度泛函方法,计算了木榄醇A~C光学异构体的旋光度、红外振动光谱和振动圆二色谱,证实了实验报道的天然木榄醇A~C的绝对构型是(+)-1S,3R,归属了红外振动光谱,指出了圆二色谱具有不同的特征。在圆二色谱中,天然木榄醇A具有一个强的正Cotton效应,天然木榄醇B~C具有一个强的负Cotton效应和一个强的正Cotton效应,但木榄醇C的两个Cotton效应相距较远。更多还原

【Abstract】 The optical rotations,IR and VCD spectra of bruguierols A-C were calculated with the gradient-corrected DFT method.It was confirmed that absolute configurations of natural bruguierols A-C are(+)–1S,3R as experimentally reported.Furthermore,the normal vibrational modes were assigned and the VCD spectra were characterized.Concretely,the VCD spectroscopy of bruguierol A has one strong positive Cotton effect at 1 027 cm-1,bruguierol B possesses one strong negative Cotton effect at 1 089 cm-1 and one strong positive Cotton effect at 1 011 cm-1,and bruguierol C exhibits one strong negative Cotton effect at 1 323 cm-1 and one strong positive Cotton effect at 1 018 cm-1.Accordingly,it was found that the gap(215 cm-1) between two VCD bands in bruguierol C is relatively larger than(78 cm-1) that in bruguierol B.更多还原