Acta Cryst. (2001). E57, o1007-o1009  [ doi:10.1107/S1600536801015847 ]

Octahydro-7a,8'-dimethylspiro[isobenzofuran-4(1H),4'(3'H)-[1H-7,9a]methanocyclohepta[c]pyran]-1',3,9'(3aH,4'aH)-trione

H. Shi, Y. J. Pan, X. Q. Zhang and K. B. Yu

Abstract: The title compound, C₂₀H₂₆O₅, or ludongnin B, which has been isolated from Rabdosia var lophanthoides, is composed of three six-membered rings and two five-membered rings. The isobenzofuran ring system couples almost orthogonally to the methanocyclohepta[c]pyran moiety through a spiro-C atom.

Online 6 October 2001

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