K. Peters et al., Crystal structure of (3aR*, 6aR*, 9aR*, 9bS*)-decahydro-8,8-dimethyl-6,9-dioxo-9a-methoxycarbonylazuleno[4,5-c]furan-1(3H)-one, (CH3)(2)C10H8O2(COOCH3)(2), Z KRIST-NEW, 214(3), 1999, pp. 359-360
C16H20O6, manoclinic, P12(1)/c1 (No. 14), a = 12.306(2) Angstrom, b = 8.820
(1) Angstrom, c = 28.342(5) Angstrom, beta = 96.42(1)degrees, V = 3056.9 An
gstrom(3), Z = 8, R-gt(F) = 0.096, R-W(F) = 0.092, T = 293 K.