ABSTRACT: The title compound, C(32)H(40)O(10), also known as xyloccensin L [systematic name: (1R,4aR,4bS,5aR,6aR,9R,10S,10aS,10bR,2aR,13R)-1-(furan-3-yl)-6a-hy-droxy-10-(2-meth-oxy-2-oxoeth-yl)-9,10a,12a-trimethyl-3-oxododeca-hydro-1H,3H,5aH-6,9-methano-isochromeno[6,5-f]oxireno[g]chromen-13-yl (2E)-2-methyl-but-2-enoate], is a limonoid with a C1-C29 oxygen bridge: this is the first report of the X-ray crystal structure of such a limonoid. Two fused pyran rings and two cyclo-hexane rings adopt boat conformations, while another cyclo-hexane ring and the d-lactone ring are in half-chair conformations. The mol-ecular structure is stabilized by intra-molecular O-H?O hydrogen bonding.