本文用PCILO方法研究了标题化合物的孤立态分子构象,与用X射线晶体结构测定的分子构象进行了对比和印证。在此类三岔共轭体系分子中,由于空间位阻的影响,只有一个分岔与主干共轭链基本共面,起着端基的作用;另一分岔不与主干共轭链共面,只起代基的作用。参照苯基,在烯链异侧的反式乙酰基属于端基性质。 In this paper, PCILO method was used to study the isolated molecular conformation of the title compound, which was compared with the molecular conformation determined by X-ray crystal structure. In such tripartite conjugate system molecules, only one bifurcation is basically coplanar with the backbone conjugate chain due to steric hindrance and plays the role of an end group. The other bifurcation does not co-planar with the backbone conjugate chain , Only played the role of generation. With reference to the phenyl group, the trans acetyl group on the opposite side of the alkene belongs to the end group nature.