title: 3-[(5-Methyl-furan-2-yl)methyl-ene]-1,5-dioxaspiro-[5.5]undecane-2,4-dione.
abstract: There are two crystallographically independent mol-ecules in the asymmetric unit of the title compound, C(15)H(16)O(5). In each, the 1,3-dioxane ring is in an envelope conformation with the C atom common to the cyclo-hexane ring forming the flap. The dihedral angles between the five essentially planar [maximum deviations from the least-squares planes of 0.049 (3) and 0.042 (3) Å] atoms of the 1,3-dioxane ring and the furan ring in the two mol-ecules are 7.15 (1) and 6.80 (1)°. The crystal structure is stabilized by weak inter-molecular C-H⋯O hydrogen bonds.
authors.affiliation: Microscale Science Institute, Department of Chemistry and Chemical Engineering, Weifang University, Weifang 261061, People's Republic of China.
authors.forename: Wu-Lan
authors.initials: WL
authors.lastname: Zeng
authors.forename: Hua-Xiang
authors.initials: HX
authors.lastname: Zhang
authors.forename: Fang-Fang
authors.initials: FF
authors.lastname: Jian