DIMETHYL XAMETHYL-1(E),2(E)-CYCLOPENTANDIYLIDENE]DIACETATE, C17H26O4

To establish the conformation of the diene system of the title compoun d, its structure was determined by X-ray analysis. The non-planar buta diene fragment is in a gauche conformation [torsion angle 44.8 (9)degr ees]. The methoxycarbonyl groups are fully eclipsed with respect to th e single bond in the diene system. The five-membered ring adopts a dis torted envelope conformation with the apical C atom at position 3. In the cyclopentane ring, elongations of C-C bonds [1.587 (2) and 1.575 ( 2) angstrom] and contractions of C-C-C bond angles [99.9 (2), 104.0 (2 ),103.3 (2)degrees] involving atoms at positions 3, 4 and 5 are observ ed.