乙酰丙酮和1-萘甲酸甲酯加成物C17H18O4的晶体结构和分子力学计算

Crystal Structure and Molecular Mechanics Calculations of the Addition Product of Acetylacetone and Methyl 1-Naphthoate,C17H18O4

The structure of the product from the 2+2] photocycloaddition of acetylacetone to methyl 1-naphthoate was determined by X-ray crystallography. Crystal data. C_(17)H_(18)O_4, triclinic, P_1~-, a=0.7401(1), b=0.7656(1), c=1.3882(1) nm, α=84.75(1), β=86.49(1), γ=65.08(1)°, V=0.7102 nm, Z=2, D_c=1.339 g·cm~(-3), μ(MoK_a)=1.0 cm~(-1), F(000)=304. The structure was solved by direct methods and refined to final R=0.049 for 2442 MoKa reflections. The particular bridged structure of the product molecule indicates a 2+2+2] intramolecular cycloaddition in succession to the primary 2+2] photocycloaddition. Molecular mechanics calculations confirmed further that the molecular structure of the ultimate product takes a configuration of comparatively favourable steric energy even though the bridged structure itself is rather strained.