title: Structure of asperketal B.
abstract: 3,7,11-Trimethyl-13-oxabicyclo[8.3.0]trideca-2,6-diene-12-spiro-2' -(5',5'-dimethyltetrahydrofuran), asperketal B, C20H30O2, M(r) = 302.46, orthorhombic, P2(1)2(1)2(1), a = 10.064(1), b = 22.214(2), c = 8.330 (1) A, V = 1862.3 A3, Z = 4, Dx = 1.08 g cm-3, Cu K alpha, lambda = 1.54178 A, mu = 4.55 cm-1, F(000) = 664, T = 294 (1) K, R = 0.031, wR = 0.027 for 953 data. The backbone of the molecule is composed of a cyclodecadiene ring which is cis fused to a bicyclic ketal system. The relative configurations at C(1), C(10), C(11) and C(12) are 1S*, 10R*, 11R* and 12R*.
authors.affiliation: Department of Chemistry and Biochemistry, University of Oklahoma, Norman 73019.
authors.forename: X
authors.initials: X
authors.lastname: Ji
authors.forename: D
authors.initials: D
authors.lastname: van der Helm
authors.forename: J
authors.initials: J
authors.lastname: Shin
authors.forename: W
authors.initials: W
authors.lastname: Fenical
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003460:Crystallization; D004224:Diterpenes / Q000737:chemistry*; D005583:Fourier Analysis; D005663:Furans / Q000737:chemistry*; D015394:Molecular Structure; D014961:X-Ray Diffraction
chemical_list: D004224:Diterpenes; D005663:Furans; C077034:asperketal B