title: Methyl 2,2-dimeth-oxy-8-oxo-1-oxaspiro-[4.5]deca-6,9-diene-3-carboxyl-ate.
abstract: In the title mol-ecule, C(13)H(16)O(6), the cyclo-hexa-1,4-diene ring adopts a flat boat conformation (r.m.s. deviation from planarity = 0.060 Å) and the five-membered tetra-hydro-furan ring adopts an envelope conformation with the carboxyl group-substituted C atom as the flap. The dihedral angle at the spiro junction is 89.1 (1)°. In the crystal, mol-ecules are linked through weak C-H⋯O and van der Waals inter-actions.
authors.affiliation: School of Chemistry and Chemical Engineering, Southeast University, Southeast University Road 2, Jiangning District, 211189 Nanjing,  People's Republic of China.
authors.forename: Yongbing
authors.initials: Y
authors.lastname: Lou