cis-3,5a-Dimethyl-1-oxo-5a,6,8,9-tetrahydro-1H,7H-pyrano[4,3-b][1]benzopyran-6-yl Formate

Characterization of the title compound, C₁₅H₁₆O₅, by X-ray diffraction affirms its linearly fused tricyclic structure and the chair conformation of the cyclohexane ring on which the methyl and adjacent formyloxy groups are cis, the former being axial and the latter equatorial. The C=C bond γ,δ to the carbonyl is longer while the C=C bond α,β to the carbonyl is shorter than their counterparts in a 3-substituted 4-hydroxy-6-methyl-2-pyrone.

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