2-Oxo-2H-chromen-7-yl 3-methyl-butano-ate.

Abstract

The title compound, C₁₄H₁₄O₄, was synthesized by O-acyl-ation of umbelliferone with isovaleryl chloride in the presence of diethyl ether as a solvent and pyridine as a base. The side chain moiety i.e. the acetate fragment linking to the methyl-ethyl group is almost orthogonal to the almost planar (r.m.s deviation = 0.020 Å) coumarin ring system, making an angle of 76.26 (7)°. In the crystal, the mol-ecules form centrosymmetric dimers through pairwise C-H⋯O hydrogen bonds, generating R ₂ ²(8) and R ₂ ²(18) loops that lie within the crystallographic ac plane and propagate along the [001] direction.