############################################################################## ### ### ### Electronic paper (Acta Crystallographica Section E) ### ### ### ############################################################################## # # # This CIF contains the data in a paper accepted for publication in Acta # # Crystallographica Section E. It conforms to the requirements of Notes # # for Authors for Section E, and has been peer reviewed under the auspices # # of the IUCr Commission on Journals. # # # # Full details of the Crystallographic Information File format # # are given in the paper "The Crystallographic Information File (CIF): # # a New Standard Archive File for Crystallography" by S. R. Hall, F. H. # # Allen and I. D. Brown [Acta Cryst. (1991), A47, 655-685]. # # # # The current version of the core CIF dictionary is obtainable from # # ftp://ftp.iucr.org/pub/cif_core.dic. The current version number is 2.4. # # # # Software is freely available for graphical display of the structure(s) in # # this CIF. For information consult the CIF home page http://www.iucr.org/ # # cif/home.html # # # # This file may be used for bona fide research purposes within the # # scientific community so long as proper attribution is given to the journal # # article from which it was obtained. # # # ############################################################################## data_global _audit_creation_method 'form.cif (version 2.0)' _journal_data_validation_number ? _journal_date_recd_electronic 2009-07-17 _journal_date_accepted 2009-08-21 _journal_name_full 'Acta Crystallographica, Section E' _journal_year 2009 _journal_volume 65 _journal_issue 10 _journal_page_first o2330 _journal_page_last o2330 _journal_paper_category QO _journal_coeditor_code HG2542 _publ_contact_author_name 'Professor Mat\\'ias L\\'opez' _publ_contact_author_address ; Instituto de Bioorg\\'anica A. Gonz\\'alez Universidad de La Laguna Astrof\\'isico F. S\\'anchez,#2 38206 La Laguna, Tenerife Spain ; _publ_contact_author_email 'malopez@ull.es' _publ_contact_author_fax '34 922 318570' _publ_contact_author_phone '34 922 318588' _publ_section_title ; (-)-Istanbulin A ; loop_ _publ_author_name _publ_author_footnote _publ_author_address 'L\'opez-Rodr\'iguez, Mat\'ias' . ; Instituto de Bioorg\'anica "A. Gonz\'alez" Universidad de La Laguna Astrof\'isico Francisco S\'anchez, 2 38206 La Laguna, Tenerife Spain ; 'Reina, Mat\'ias' . ; Instituto de Productos Naturales y Agrobiolog\'ia (IPNA-CSIC) Astrof\'isico Francisco S\'anchez, 3 38206 La Laguna, Tenerife Spain ; 'Dom\'inguez-D\'iaz, D.M.' . ; Instituto de Productos Naturales y Agrobiolog\'ia (IPNA-CSIC) Astrof\'isico Francisco S\'anchez, 3 38206 La Laguna, Tenerife Spain ; 'Fajardo, V.' . ; Facultad de Ciencias Universidad de Magallanes (UMAG) Punta Arenas Chile ; 'Villarroel, L.' . ; Facultad de Qu\'imica y Biolog\'ia Universidad de Santiago de Chile Chile ; data_I _audit_creation_method SHELXL-97 _chemical_name_systematic ; 9a-hydroxy-3,4a,5-trimethyl-4a,6,7,8a,9,9a-hexahydro-4H,5H- naphtho[2,3-b]furan-2,8-dione ; _chemical_name_common '(-)-Istanbulin A' _chemical_formula_moiety 'C15 H20 O4' _chemical_formula_sum 'C15 H20 O4' _chemical_formula_iupac 'C15 H20 O4' _chemical_formula_weight 264.31 _chemical_melting_point ? _symmetry_cell_setting monoclinic _symmetry_space_group_name_H-M 'P 21' _symmetry_space_group_name_Hall 'P 2yb' loop_ _symmetry_equiv_pos_as_xyz 'x, y, z' '-x, y+1/2, -z' _cell_length_a 7.432(4) _cell_length_b 13.010(6) _cell_length_c 8.161(6) _cell_angle_alpha 90.00 _cell_angle_beta 115.47(4) _cell_angle_gamma 90.00 _cell_volume 712.4(8) _cell_formula_units_Z 2 _cell_measurement_reflns_used 297 _cell_measurement_theta_min 4.3 _cell_measurement_theta_max 23.7 _cell_measurement_temperature 293(2) _exptl_crystal_description block _exptl_crystal_colour colourless _exptl_crystal_size_max 0.45 _exptl_crystal_size_mid 0.35 _exptl_crystal_size_min 0.25 _exptl_crystal_density_diffrn 1.232 _exptl_crystal_density_meas ? _exptl_crystal_density_method 'not measured' _exptl_crystal_F_000 284 _exptl_absorpt_coefficient_mu 0.088 _exptl_absorpt_correction_type none _exptl_absorpt_process_details ? _exptl_absorpt_correction_T_min ? _exptl_absorpt_correction_T_max ? _exptl_special_details ; ; _diffrn_ambient_temperature 293(2) _diffrn_radiation_type MoK\a _diffrn_radiation_wavelength 0.71073 _diffrn_radiation_source 'fine-focus sealed tube' _diffrn_radiation_monochromator graphite _diffrn_measurement_device_type 'Enraf--Nonius KappaCCD' _diffrn_measurement_device '95mm CCDcamera on \\k goniostat' _diffrn_measurement_method '\f and \w' _diffrn_detector_area_resol_mean 9 _diffrn_reflns_number 4410 _diffrn_reflns_av_R_equivalents 0.0180 _diffrn_reflns_av_sigmaI/netI 0.0217 _diffrn_reflns_theta_min 6.41 _diffrn_reflns_theta_max 27.50 _diffrn_reflns_theta_full 27.50 _diffrn_measured_fraction_theta_max 0.981 _diffrn_measured_fraction_theta_full 0.981 _diffrn_reflns_limit_h_min -9 _diffrn_reflns_limit_h_max 9 _diffrn_reflns_limit_k_min -16 _diffrn_reflns_limit_k_max 15 _diffrn_reflns_limit_l_min -10 _diffrn_reflns_limit_l_max 10 _diffrn_standards_number ? _diffrn_standards_interval_count ? _diffrn_standards_interval_time ? _diffrn_standards_decay_% ? _refine_special_details ; Refinement of F^2^ against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F^2^, conventional R-factors R are based on F, with F set to zero for negative F^2^. The threshold expression of F^2^ > \s(F^2^) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F^2^ are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger. ; _reflns_number_total 1678 _reflns_number_gt 1485 _reflns_threshold_expression I>2\s(I) _refine_ls_structure_factor_coef Fsqd _refine_ls_matrix_type full _refine_ls_R_factor_all 0.0451 _refine_ls_R_factor_gt 0.0378 _refine_ls_wR_factor_gt 0.0912 _refine_ls_wR_factor_ref 0.0951 _refine_ls_goodness_of_fit_ref 1.039 _refine_ls_restrained_S_all 1.038 _refine_ls_number_reflns 1678 _refine_ls_number_parameters 186 _refine_ls_number_restraints 1 _refine_ls_hydrogen_treatment mixed _refine_ls_weighting_scheme calc _refine_ls_weighting_details 'calc w=1/[\s^2^(Fo^2^)+(0.0482P)^2^+0.0898P] where P=(Fo^2^+2Fc^2^)/3' _atom_sites_solution_hydrogens difmap _atom_sites_solution_primary direct _atom_sites_solution_secondary difmap _refine_ls_shift/su_max 0.001 _refine_ls_shift/su_mean 0.001 _refine_diff_density_max 0.196 _refine_diff_density_min -0.115 _refine_ls_extinction_method none _refine_ls_extinction_coef ? loop_ _atom_type_symbol _atom_type_description _atom_type_scat_dispersion_real _atom_type_scat_dispersion_imag _atom_type_scat_source 'C' 'C' 0.0033 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'H' 'H' 0.0000 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' 'O' 'O' 0.0106 0.0000 'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4' _computing_data_collection 'COLLECT (Nonius, 2000)' _computing_cell_refinement 'SCALEPACK (Otwinowski & Minor, 1997)' _computing_data_reduction 'SCALEPACK and DENZO (Otwinowski & Minor, 1997)' _computing_structure_solution 'SIR97 (Altomare et al., 1999)' _computing_structure_refinement 'SHELXL97 (Sheldrick, 2008 )' _computing_molecular_graphics 'PLATON (Spek, 2009)' _computing_publication_material 'WinGX (Farrugia,1999)' loop_ _atom_site_type_symbol _atom_site_label _atom_site_fract_x _atom_site_fract_y _atom_site_fract_z _atom_site_U_iso_or_equiv _atom_site_adp_type _atom_site_calc_flag _atom_site_refinement_flags _atom_site_occupancy _atom_site_disorder_assembly _atom_site_disorder_group O O1 0.4955(3) 0.50383(14) 0.8319(2) 0.0568(5) Uani d . 1 . . O O2 0.5421(4) 0.5731(2) 0.6018(3) 0.0869(7) Uani d . 1 . . O O3 0.6082(2) 0.37119(15) 1.04064(19) 0.0521(4) Uani d . 1 . . H H3 0.713(5) 0.354(3) 1.018(4) 0.079(9) Uiso d . 1 . . O O4 -0.0560(2) 0.35876(16) 0.9801(3) 0.0635(5) Uani d . 1 . . C C1 0.0324(3) 0.28290(19) 0.9675(3) 0.0456(5) Uani d . 1 . . C C2 -0.0216(4) 0.1763(2) 0.9971(4) 0.0635(7) Uani d . 1 . . H H2A -0.1422 0.1778 1.0153 0.079(9) Uiso calc R 1 . . H H2B 0.0844 0.1476 1.1053 0.073(9) Uiso calc R 1 . . C C3 -0.0542(4) 0.1087(2) 0.8333(4) 0.0643(7) Uani d . 1 . . H H3A -0.1759 0.1299 0.7312 0.074(9) Uiso calc R 1 . . H H3B -0.0713 0.0379 0.8615 0.059(8) Uiso calc R 1 . . C C4 0.1189(4) 0.11441(18) 0.7792(3) 0.0518(6) Uani d . 1 . . H H4 0.2377 0.0891 0.8827 0.059(7) Uiso calc R 1 . . C C5 0.1632(3) 0.22659(16) 0.7435(3) 0.0375(4) Uani d . 1 . . C C6 0.3567(3) 0.22904(18) 0.7137(3) 0.0448(5) Uani d . 1 . . H H6A 0.4602 0.1896 0.8084 0.057(7) Uiso calc R 1 . . H H6B 0.3309 0.1977 0.5979 0.050(7) Uiso calc R 1 . . C C7 0.4259(3) 0.33673(18) 0.7168(3) 0.0422(5) Uani d . 1 . . C C8 0.4541(3) 0.40177(17) 0.8797(3) 0.0412(5) Uani d . 1 . . C C9 0.2648(3) 0.40183(17) 0.9078(3) 0.0407(5) Uani d . 1 . . H H9A 0.1589 0.4368 0.8076 0.036(5) Uiso calc R 1 . . H H9B 0.2875 0.4377 1.0192 0.043(6) Uiso calc R 1 . . C C10 0.2059(3) 0.29068(16) 0.9181(3) 0.0372(4) Uani d . 1 . . H H10 0.3200 0.2583 1.0170 0.044(6) Uiso calc R 1 . . C C11 0.4554(3) 0.3931(2) 0.5961(3) 0.0488(6) Uani d . 1 . . C C12 0.5040(4) 0.4988(3) 0.6676(4) 0.0588(6) Uani d . 1 . . C C13 0.4395(4) 0.3664(3) 0.4119(3) 0.0668(8) Uani d . 1 . . H H13A 0.5521 0.3940 0.3982 0.090 Uiso calc R 1 . . H H13B 0.3190 0.3950 0.3207 0.090 Uiso calc R 1 . . H H13C 0.4374 0.2930 0.3988 0.090 Uiso calc R 1 . . C C14 -0.0102(3) 0.27228(19) 0.5782(3) 0.0512(5) Uani d . 1 . . H H14A 0.0173 0.3431 0.5648 0.090 Uiso calc R 1 . . H H14B -0.1303 0.2676 0.5947 0.090 Uiso calc R 1 . . H H14C -0.0266 0.2348 0.4713 0.090 Uiso calc R 1 . . C C15 0.0800(5) 0.0415(2) 0.6210(5) 0.0771(9) Uani d . 1 . . H H15A 0.1886 0.0454 0.5872 0.090 Uiso calc R 1 . . H H15B -0.0415 0.0607 0.5195 0.090 Uiso calc R 1 . . H H15C 0.0685 -0.0276 0.6569 0.090 Uiso calc R 1 . . loop_ _atom_site_aniso_label _atom_site_aniso_U_11 _atom_site_aniso_U_22 _atom_site_aniso_U_33 _atom_site_aniso_U_12 _atom_site_aniso_U_13 _atom_site_aniso_U_23 O1 0.0612(10) 0.0542(10) 0.0633(10) -0.0224(8) 0.0348(8) -0.0122(8) O2 0.0968(16) 0.0837(16) 0.0944(16) -0.0249(13) 0.0548(14) 0.0156(13) O3 0.0339(7) 0.0817(12) 0.0434(7) -0.0078(8) 0.0194(6) -0.0091(8) O4 0.0465(9) 0.0680(12) 0.0928(12) -0.0034(9) 0.0460(9) -0.0125(10) C1 0.0355(10) 0.0562(14) 0.0480(11) -0.0048(10) 0.0208(9) -0.0015(11) C2 0.0559(14) 0.0680(18) 0.0766(17) -0.0052(13) 0.0378(13) 0.0159(15) C3 0.0604(15) 0.0452(14) 0.0848(18) -0.0128(12) 0.0289(14) 0.0092(14) C4 0.0517(12) 0.0354(11) 0.0592(13) 0.0019(10) 0.0153(11) 0.0043(11) C5 0.0343(9) 0.0339(10) 0.0398(9) 0.0004(8) 0.0118(8) -0.0005(9) C6 0.0463(11) 0.0476(12) 0.0440(10) 0.0054(10) 0.0228(9) -0.0063(10) C7 0.0325(9) 0.0558(13) 0.0408(10) -0.0020(9) 0.0183(8) -0.0071(10) C8 0.0384(10) 0.0472(12) 0.0423(10) -0.0099(9) 0.0213(8) -0.0077(9) C9 0.0367(9) 0.0430(12) 0.0488(11) -0.0050(8) 0.0244(9) -0.0109(9) C10 0.0282(8) 0.0438(11) 0.0407(10) 0.0015(8) 0.0161(7) 0.0002(9) C11 0.0378(10) 0.0703(16) 0.0414(10) -0.0015(10) 0.0201(8) 0.0010(11) C12 0.0495(13) 0.0745(18) 0.0584(13) -0.0133(12) 0.0290(11) 0.0039(13) C13 0.0641(14) 0.099(2) 0.0423(11) -0.0002(16) 0.0278(11) 0.0043(14) C14 0.0465(12) 0.0464(13) 0.0465(11) 0.0016(10) 0.0066(9) 0.0057(11) C15 0.089(2) 0.0412(14) 0.093(2) -0.0098(14) 0.0316(18) -0.0157(14) _geom_special_details ; All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. ; loop_ _geom_bond_atom_site_label_1 _geom_bond_atom_site_label_2 _geom_bond_site_symmetry_2 _geom_bond_distance _geom_bond_publ_flag O1 C12 . 1.371(3) ? O1 C8 . 1.454(3) ? O2 C12 . 1.198(4) ? O3 C8 . 1.379(3) ? O3 H3 . 0.90(4) ? O4 C1 . 1.214(3) ? C1 C2 . 1.493(4) ? C1 C10 . 1.511(3) ? C2 C3 . 1.530(4) ? C2 H2A . 0.9700 ? C2 H2B . 0.9700 ? C3 C4 . 1.532(4) ? C3 H3A . 0.9700 ? C3 H3B . 0.9700 ? C4 C15 . 1.526(4) ? C4 C5 . 1.551(3) ? C4 H4 . 0.9800 ? C5 C14 . 1.529(3) ? C5 C6 . 1.558(3) ? C5 C10 . 1.561(3) ? C6 C7 . 1.489(3) ? C6 H6A . 0.9700 ? C6 H6B . 0.9700 ? C7 C11 . 1.320(3) ? C7 C8 . 1.512(3) ? C8 C9 . 1.519(3) ? C9 C10 . 1.524(3) ? C9 H9A . 0.9700 ? C9 H9B . 0.9700 ? C10 H10 . 0.9800 ? C11 C12 . 1.477(4) ? C11 C13 . 1.497(3) ? C13 H13A . 0.9600 ? C13 H13B . 0.9600 ? C13 H13C . 0.9600 ? C14 H14A . 0.9600 ? C14 H14B . 0.9600 ? C14 H14C . 0.9600 ? C15 H15A . 0.9600 ? C15 H15B . 0.9600 ? C15 H15C . 0.9600 ? loop_ _geom_angle_atom_site_label_1 _geom_angle_atom_site_label_2 _geom_angle_atom_site_label_3 _geom_angle_site_symmetry_1 _geom_angle_site_symmetry_3 _geom_angle _geom_angle_publ_flag C12 O1 C8 . . 108.86(19) ? C8 O3 H3 . . 108(2) ? O4 C1 C2 . . 123.30(19) ? O4 C1 C10 . . 121.5(2) ? C2 C1 C10 . . 115.2(2) ? C1 C2 C3 . . 110.2(2) ? C1 C2 H2A . . 109.6 ? C3 C2 H2A . . 109.6 ? C1 C2 H2B . . 109.6 ? C3 C2 H2B . . 109.6 ? H2A C2 H2B . . 108.1 ? C2 C3 C4 . . 112.8(2) ? C2 C3 H3A . . 109.0 ? C4 C3 H3A . . 109.0 ? C2 C3 H3B . . 109.0 ? C4 C3 H3B . . 109.0 ? H3A C3 H3B . . 107.8 ? C15 C4 C3 . . 109.7(2) ? C15 C4 C5 . . 113.8(2) ? C3 C4 C5 . . 111.89(19) ? C15 C4 H4 . . 107.0 ? C3 C4 H4 . . 107.0 ? C5 C4 H4 . . 107.0 ? C14 C5 C4 . . 111.40(18) ? C14 C5 C6 . . 109.80(18) ? C4 C5 C6 . . 109.48(18) ? C14 C5 C10 . . 111.15(18) ? C4 C5 C10 . . 107.89(17) ? C6 C5 C10 . . 106.99(16) ? C7 C6 C5 . . 110.60(17) ? C7 C6 H6A . . 109.5 ? C5 C6 H6A . . 109.5 ? C7 C6 H6B . . 109.5 ? C5 C6 H6B . . 109.5 ? H6A C6 H6B . . 108.1 ? C11 C7 C6 . . 132.6(2) ? C11 C7 C8 . . 109.9(2) ? C6 C7 C8 . . 117.24(18) ? O3 C8 O1 . . 109.53(17) ? O3 C8 C7 . . 114.85(19) ? O1 C8 C7 . . 103.91(17) ? O3 C8 C9 . . 107.47(17) ? O1 C8 C9 . . 110.88(18) ? C7 C8 C9 . . 110.20(16) ? C8 C9 C10 . . 108.33(16) ? C8 C9 H9A . . 110.0 ? C10 C9 H9A . . 110.0 ? C8 C9 H9B . . 110.0 ? C10 C9 H9B . . 110.0 ? H9A C9 H9B . . 108.4 ? C1 C10 C9 . . 112.13(17) ? C1 C10 C5 . . 110.24(17) ? C9 C10 C5 . . 114.02(16) ? C1 C10 H10 . . 106.7 ? C9 C10 H10 . . 106.7 ? C5 C10 H10 . . 106.7 ? C7 C11 C12 . . 108.2(2) ? C7 C11 C13 . . 130.8(3) ? C12 C11 C13 . . 120.9(2) ? O2 C12 O1 . . 121.3(3) ? O2 C12 C11 . . 129.7(2) ? O1 C12 C11 . . 108.9(2) ? C11 C13 H13A . . 109.5 ? C11 C13 H13B . . 109.5 ? H13A C13 H13B . . 109.5 ? C11 C13 H13C . . 109.5 ? H13A C13 H13C . . 109.5 ? H13B C13 H13C . . 109.5 ? C5 C14 H14A . . 109.5 ? C5 C14 H14B . . 109.5 ? H14A C14 H14B . . 109.5 ? C5 C14 H14C . . 109.5 ? H14A C14 H14C . . 109.5 ? H14B C14 H14C . . 109.5 ? C4 C15 H15A . . 109.5 ? C4 C15 H15B . . 109.5 ? H15A C15 H15B . . 109.5 ? C4 C15 H15C . . 109.5 ? H15A C15 H15C . . 109.5 ? H15B C15 H15C . . 109.5 ? loop_ _geom_torsion_atom_site_label_1 _geom_torsion_atom_site_label_2 _geom_torsion_atom_site_label_3 _geom_torsion_atom_site_label_4 _geom_torsion_site_symmetry_1 _geom_torsion_site_symmetry_2 _geom_torsion_site_symmetry_3 _geom_torsion_site_symmetry_4 _geom_torsion _geom_torsion_publ_flag O4 C1 C2 C3 . . . . 126.2(3) ? C10 C1 C2 C3 . . . . -53.2(3) ? C1 C2 C3 C4 . . . . 51.1(3) ? C2 C3 C4 C15 . . . . 177.4(2) ? C2 C3 C4 C5 . . . . -55.3(3) ? C15 C4 C5 C14 . . . . 59.4(3) ? C3 C4 C5 C14 . . . . -65.6(3) ? C15 C4 C5 C6 . . . . -62.2(3) ? C3 C4 C5 C6 . . . . 172.73(19) ? C15 C4 C5 C10 . . . . -178.3(2) ? C3 C4 C5 C10 . . . . 56.6(2) ? C14 C5 C6 C7 . . . . 69.0(2) ? C4 C5 C6 C7 . . . . -168.42(18) ? C10 C5 C6 C7 . . . . -51.8(2) ? C5 C6 C7 C11 . . . . -120.6(2) ? C5 C6 C7 C8 . . . . 53.2(2) ? C12 O1 C8 O3 . . . . 119.6(2) ? C12 O1 C8 C7 . . . . -3.5(2) ? C12 O1 C8 C9 . . . . -121.9(2) ? C11 C7 C8 O3 . . . . -117.3(2) ? C6 C7 C8 O3 . . . . 67.5(2) ? C11 C7 C8 O1 . . . . 2.3(2) ? C6 C7 C8 O1 . . . . -172.85(17) ? C11 C7 C8 C9 . . . . 121.1(2) ? C6 C7 C8 C9 . . . . -54.0(2) ? O3 C8 C9 C10 . . . . -72.0(2) ? O1 C8 C9 C10 . . . . 168.34(16) ? C7 C8 C9 C10 . . . . 53.8(2) ? O4 C1 C10 C9 . . . . 6.0(3) ? C2 C1 C10 C9 . . . . -174.5(2) ? O4 C1 C10 C5 . . . . -122.1(2) ? C2 C1 C10 C5 . . . . 57.3(2) ? C8 C9 C10 C1 . . . . 173.39(16) ? C8 C9 C10 C5 . . . . -60.4(2) ? C14 C5 C10 C1 . . . . 66.0(2) ? C4 C5 C10 C1 . . . . -56.4(2) ? C6 C5 C10 C1 . . . . -174.11(18) ? C14 C5 C10 C9 . . . . -61.1(2) ? C4 C5 C10 C9 . . . . 176.45(16) ? C6 C5 C10 C9 . . . . 58.7(2) ? C6 C7 C11 C12 . . . . 173.9(2) ? C8 C7 C11 C12 . . . . -0.3(2) ? C6 C7 C11 C13 . . . . -3.7(4) ? C8 C7 C11 C13 . . . . -177.9(2) ? C8 O1 C12 O2 . . . . -177.8(2) ? C8 O1 C12 C11 . . . . 3.5(3) ? C7 C11 C12 O2 . . . . 179.5(3) ? C13 C11 C12 O2 . . . . -2.6(4) ? C7 C11 C12 O1 . . . . -2.0(3) ? C13 C11 C12 O1 . . . . 175.8(2) ? loop_ _geom_hbond_atom_site_label_D _geom_hbond_atom_site_label_H _geom_hbond_atom_site_label_A _geom_hbond_site_symmetry_A _geom_hbond_distance_DH _geom_hbond_distance_HA _geom_hbond_distance_DA _geom_hbond_angle_DHA O3 H3 O4 1_655 0.90(4) 1.87(4) 2.750(3) 164(4)