Tricoccin R2

In the title compound, (3'S-{3'[alpha],3'[alpha][beta],5'[alpha][alpha],7'[alpha][R*(R*)],8'b[beta]}-4-(2,5-dihydro-2-methyl-5-oxo-2-furanyl)-3'-(3-furanyl)-4,5,5',5'[alpha]-tetrahydro-5,5- dimethylspiro[furan-2(3H),7'(4'H)-1H,3H-3[alpha],8b]methanobenzo[1,2 - b:3,4 - c']difuran)-1'-one, C₂₅H₂₆O₇, some C-C bonds and C-C-C angles deviate significantly from their expected values. Both the terminal five-membered rings are nearly planar. The fused five-membered rings, B, C and E, have half-chair, distorted envelope and half-chair conformations, respectively. The six-membered ring is in a slightly distorted sofa conformation. The structure is stabilized by van der Waals interactions.

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