##############################################################################
###                                                                        ###
###        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 2.1.    #
#                                                                            #
# 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                                                              #
#                                                                            #
#            Copyright International Union of Crystallography                #
#                                                                            #
##############################################################################
                                             
data_global
_audit_creation_method     'from SHELXL97 CIF and IUCr SHELXL97-template'
_journal_date_recd_electronic     2006-07-17
_journal_date_accepted     2006-08-10
_journal_name_full     'Acta Crystallographica, Section E'
_journal_year     2006
_journal_volume     62
_journal_issue      9
_journal_page_first     o3885
_journal_page_last     o3886
_journal_paper_category     EO
_journal_coeditor_code     EZ2019
_publ_contact_author_name     'Dr Yu Peng'
_publ_contact_author_address
;
State Key Laboratory of Applied Organic Chemstry
College of Chemical Engineering
Lanzhou University
Lanzhou 730000
P.R.China
;
_publ_contact_author_email     pengyu@lzu.edu.cn
_publ_contact_author_fax     '+86-931-8912582'
_publ_contact_author_phone     '+86-931-8912595'
_publ_section_title
;\
(2S,7R)-2-Benzyloxy-7-bromomethyl-1,2,7-trimethylbicyclo[2.2.1]\
heptane
;
loop_
    _publ_author_name
    _publ_author_footnote
    _publ_author_address
    'Ya-Wen Wang' .
;
Department of Chemistry
Lanzhou University
Lanzhou 730000
People's Republic of China
;
    'Yu Peng' .
;
College of Chemical Engineering
Lanzhou University
Lanzhou 730000
People's Republic of China
;
data_I
_chemical_name_systematic
;
(2S,7R)-2-Benzyloxy-7-bromomethyl-1,2,7-trimethylbicyclo[2.2.1]heptane
;
_chemical_name_common     ?
_chemical_formula_moiety     'C18 H25 Br O'
_chemical_formula_sum     'C18 H25 Br O'
_chemical_formula_iupac     'C18 H25 Br O'
_chemical_formula_weight     337.29
_chemical_melting_point     ?
_symmetry_cell_setting     'monoclinic'
_symmetry_space_group_name_H-M     'P 21'
loop_
    _symmetry_equiv_pos_as_xyz
    'x, y, z'
    '-x, y+1/2, -z'
_cell_length_a     7.1721(3)
_cell_length_b     7.9624(3)
_cell_length_c     14.5849(6)
_cell_angle_alpha     90.00
_cell_angle_beta     95.719(2)
_cell_angle_gamma     90.00
_cell_volume     828.76(6)
_cell_formula_units_Z     2
_cell_measurement_reflns_used     1962
_cell_measurement_theta_min     2.6
_cell_measurement_theta_max     23.6
_cell_measurement_temperature     294(2)
_exptl_crystal_description     block
_exptl_crystal_colour     colorless
_exptl_crystal_size_max     0.43
_exptl_crystal_size_mid     0.27
_exptl_crystal_size_min     0.26
_exptl_crystal_density_diffrn     1.352
_exptl_crystal_density_meas     ?
_exptl_crystal_density_method     'not measured'
_exptl_crystal_F_000     352
_exptl_absorpt_coefficient_mu     2.475
_exptl_absorpt_correction_type     'none'
_exptl_absorpt_correction_T_min     0.4159
_exptl_absorpt_correction_T_max     0.5655
_exptl_special_details
;
 [α]D²⁰ -33 (c 1.7, CHCl₃); IR (film): 3006,
2956, 2874, 1605, 1455, 1384, 1312, 1250, 1120, 1081, 734, 696 cm⁻¹; ¹H
NMR (300 MHz, CDCl₃): δ 7.33 (d, 4H, J = 4.2 Hz), 7.28--7.24
(m, 1H), 4.45 (d, 2H, J = 3.0 Hz), 3.78 (d, 1H,
J = 9.9 Hz), 3.21 (d, 1H, J = 9.9 Hz), 2.62--2.55
(m, 1H), 2.03 (t, 1H, J = 4.5 Hz), 1.82--1.74 (m,
2H), 1.65--1.53 (m, 1H), 1.40 (s, 3H), 1.40--1.22 (m,
2H), 1.16 (s, 3H), 0.93 (s, 3H); ¹³C NMR (75 MHz, CDCl₃): δ
140.1, 128.2 (2C), 127.0, 126.7 (2C), 83.6, 64.8, 54.5, 53.5, 43.3, 42.8,
41.1, 28.8, 26.4, 23.9, 17.5, 12.3.
;
_diffrn_ambient_temperature     294(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     'Bruker APEX CCD area-detector'
_diffrn_measurement_method     'φ and ω'
_diffrn_detector_area_resol_mean     ?
_diffrn_reflns_number     5095
_diffrn_reflns_av_R_equivalents     0.025
_diffrn_reflns_av_sigmaI/netI     0.060
_diffrn_reflns_theta_min     2.81
_diffrn_reflns_theta_max     27.51
_diffrn_reflns_theta_full     27.5
_diffrn_measured_fraction_theta_max     0.988
_diffrn_measured_fraction_theta_full     0.988
_diffrn_reflns_limit_h_min     -7
_diffrn_reflns_limit_h_max     9
_diffrn_reflns_limit_k_min     -10
_diffrn_reflns_limit_k_max     10
_diffrn_reflns_limit_l_min     -18
_diffrn_reflns_limit_l_max     18
_diffrn_standards_number     0
_diffrn_standards_interval_count     .
_diffrn_standards_interval_time     .
_diffrn_standards_decay_%     ?
_reflns_number_total     3480
_reflns_number_gt     2336
_reflns_threshold_expression     I>2σ(I)
_refine_ls_structure_factor_coef     Fsqd
_refine_ls_matrix_type     full
_refine_ls_R_factor_all     0.065
_refine_ls_R_factor_gt     0.038
_refine_ls_wR_factor_gt     0.087
_refine_ls_wR_factor_ref     0.096
_refine_ls_goodness_of_fit_ref     0.97
_refine_ls_restrained_S_all     0.99
_refine_ls_number_reflns     3480
_refine_ls_number_parameters     185
_refine_ls_number_restraints     7
_refine_ls_hydrogen_treatment     constr
_refine_ls_weighting_scheme     calc
_refine_ls_weighting_details
                 'calc w=1/[σ²(Fo²)+(0.0411P)²] where P=(Fo²+2Fc²)/3'
_atom_sites_solution_hydrogens     geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary     difmap
_refine_ls_shift/su_max     0.000
_refine_ls_shift/su_mean     0.000
_refine_diff_density_max     0.32
_refine_diff_density_min     -0.37
_refine_ls_extinction_method     SHELXL97
_refine_ls_extinction_coef     0.060(4)
_refine_ls_extinction_expression
                                  'Fc^*^=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4^'
_refine_ls_abs_structure_details     'Flack (1983)'
_refine_ls_abs_structure_Flack     0.030(12)
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 0.0016
                         '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 0.0060
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
    'Br' 'Br' -0.2901 2.4595
                         'International Tables Vol C Tables 4.2.6.8 and 6.1.1.4'
_computing_data_collection     'SMART (Bruker, 2000)'
_computing_cell_refinement     'SAINT (Bruker, 2000)'
_computing_data_reduction     'SAINT'
_computing_structure_solution     'SHELXS97 (Sheldrick, 1997)'
_computing_structure_refinement     'SHELXL97 (Sheldrick, 1997)'
_computing_molecular_graphics     'SHELXTL'
_computing_publication_material     'SHELXTL'
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
    Br Br1 0.33807(6) 0.24169(6) 1.08282(2) 0.0830(2) Uani d . 1 . .
    C C1 0.2296(6) 0.2012(6) 0.4937(3) 0.0780(14) Uani d . 1 . .
    C C2 0.1800(6) 0.2745(8) 0.4120(2) 0.0780(16) Uani d . 1 . .
    H H2 0.0609 0.3208 0.4009 0.094 Uiso calc R 1 . .
    C C3 0.2991(8) 0.2832(7) 0.3447(3) 0.0879(17) Uani d . 1 . .
    H H3 0.2608 0.3360 0.2891 0.106 Uiso calc R 1 . .
    C C4 0.4716(8) 0.2156(9) 0.3585(3) 0.0983(17) Uani d . 1 . .
    H H4 0.5545 0.2241 0.3136 0.118 Uiso calc R 1 . .
    C C6 0.4004(10) 0.1289(8) 0.5077(4) 0.1098(18) Uani d . 1 . .
    H H6 0.4364 0.0752 0.5633 0.132 Uiso calc R 1 . .
    C C7 0.0995(8) 0.1880(9) 0.5670(3) 0.128(3) Uani d U 1 . .
    H H7A -0.0225 0.2319 0.5441 0.153 Uiso calc R 1 . .
    H H7B 0.0844 0.0710 0.5832 0.153 Uiso calc R 1 . .
    C C18 0.2898(6) 0.3760(5) 0.9689(2) 0.0603(9) Uani d . 1 . .
    H H18A 0.2289 0.4802 0.9832 0.072 Uiso calc R 1 . .
    H H18B 0.4084 0.4041 0.9461 0.072 Uiso calc R 1 . .
    C C5 0.5228(9) 0.1344(8) 0.4393(5) 0.120(2) Uani d . 1 . .
    H H5 0.6394 0.0827 0.4489 0.144 Uiso calc R 1 . .
    C C8 0.0788(5) 0.2510(9) 0.7278(2) 0.0699(10) Uani d . 1 . .
    C C15 -0.0299(5) 0.2747(6) 0.9255(3) 0.0707(12) Uani d . 1 . .
    H H15A -0.0226 0.2281 0.9864 0.106 Uiso calc R 1 . .
    H H15B -0.1079 0.2047 0.8840 0.106 Uiso calc R 1 . .
    H H15C -0.0825 0.3855 0.9260 0.106 Uiso calc R 1 . .
    C C14 0.1671(4) 0.2839(4) 0.8935(2) 0.0487(9) Uani d . 1 . .
    C C13 0.1869(5) 0.3763(5) 0.7982(3) 0.0475(8) Uani d . 1 . .
    C C12 0.3983(5) 0.3471(5) 0.7893(3) 0.0530(9) Uani d . 1 . .
    H H12A 0.4237 0.3495 0.7252 0.064 Uiso calc R 1 . .
    H H12B 0.4742 0.4320 0.8230 0.064 Uiso calc R 1 . .
    C C10 0.2460(5) 0.1195(4) 0.8614(3) 0.0561(9) Uani d . 1 . .
    H H10 0.2521 0.0296 0.9074 0.067 Uiso calc R 1 . .
    C C9 0.1186(7) 0.0822(7) 0.7745(3) 0.0775(14) Uani d . 1 . .
    H H9A 0.0032 0.0304 0.7896 0.093 Uiso calc R 1 . .
    H H9B 0.1798 0.0071 0.7346 0.093 Uiso calc R 1 . .
    C C17 -0.1310(5) 0.2947(8) 0.7052(3) 0.097(2) Uani d . 1 . .
    H H17A -0.1429 0.3895 0.6644 0.146 Uiso calc R 1 . .
    H H17B -0.1847 0.3216 0.7612 0.146 Uiso calc R 1 . .
    H H17C -0.1956 0.2002 0.6762 0.146 Uiso calc R 1 . .
    C C11 0.4384(5) 0.1720(5) 0.8314(3) 0.0597(10) Uani d . 1 . .
    H H11A 0.5328 0.1774 0.8837 0.072 Uiso calc R 1 . .
    H H11B 0.4796 0.0946 0.7861 0.072 Uiso calc R 1 . .
    C C16 0.1283(6) 0.5578(5) 0.7904(3) 0.0730(12) Uani d . 1 . .
    H H16A 0.1466 0.5988 0.7301 0.110 Uiso calc R 1 . .
    H H16B 0.2025 0.6227 0.8359 0.110 Uiso calc R 1 . .
    H H16C -0.0017 0.5674 0.8002 0.110 Uiso calc R 1 . .
    O O1 0.1688(4) 0.2767(5) 0.64360(16) 0.0847(11) Uani d . 1 . .
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
    Br1 C18 . 1.978(3) y
    C1 C2 . 1.342(6) ?
    C1 C6 . 1.350(7) ?
    C1 C7 . 1.491(6) ?
    C2 C3 . 1.366(6) ?
    C2 H2 . 0.9300 ?
    C3 C4 . 1.346(7) ?
    C3 H3 . 0.9300 ?
    C4 C5 . 1.362(8) ?
    C4 H4 . 0.9300 ?
    C6 C5 . 1.394(8) ?
    C6 H6 . 0.9300 ?
    C7 O1 . 1.373(6) ?
    C7 H7A . 0.9700 ?
    C7 H7B . 0.9700 ?
    C18 C14 . 1.526(5) ?
    C18 H18A . 0.9700 ?
    C18 H18B . 0.9700 ?
    C5 H5 . 0.9300 ?
    C8 O1 . 1.457(4) ?
    C8 C9 . 1.521(8) ?
    C8 C17 . 1.547(6) ?
    C8 C13 . 1.579(6) ?
    C15 C14 . 1.533(4) ?
    C15 H15A . 0.9600 ?
    C15 H15B . 0.9600 ?
    C15 H15C . 0.9600 ?
    C14 C10 . 1.519(5) ?
    C14 C13 . 1.591(5) ?
    C13 C16 . 1.506(6) ?
    C13 C12 . 1.552(5) ?
    C12 C11 . 1.539(5) ?
    C12 H12A . 0.9700 ?
    C12 H12B . 0.9700 ?
    C10 C9 . 1.515(6) ?
    C10 C11 . 1.546(5) ?
    C10 H10 . 0.9800 ?
    C9 H9A . 0.9700 ?
    C9 H9B . 0.9700 ?
    C17 H17A . 0.9600 ?
    C17 H17B . 0.9600 ?
    C17 H17C . 0.9600 ?
    C11 H11A . 0.9700 ?
    C11 H11B . 0.9700 ?
    C16 H16A . 0.9600 ?
    C16 H16B . 0.9600 ?
    C16 H16C . 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
    C2 C1 C6 . . 118.4(4) ?
    C2 C1 C7 . . 122.5(5) ?
    C6 C1 C7 . . 119.0(5) ?
    C1 C2 C3 . . 122.1(5) ?
    C1 C2 H2 . . 119.0 ?
    C3 C2 H2 . . 119.0 ?
    C4 C3 C2 . . 120.2(5) ?
    C4 C3 H3 . . 119.9 ?
    C2 C3 H3 . . 119.9 ?
    C3 C4 C5 . . 119.0(5) ?
    C3 C4 H4 . . 120.5 ?
    C5 C4 H4 . . 120.5 ?
    C1 C6 C5 . . 120.3(5) ?
    C1 C6 H6 . . 119.8 ?
    C5 C6 H6 . . 119.8 ?
    O1 C7 C1 . . 110.2(4) ?
    O1 C7 H7A . . 109.6 ?
    C1 C7 H7A . . 109.6 ?
    O1 C7 H7B . . 109.6 ?
    C1 C7 H7B . . 109.6 ?
    H7A C7 H7B . . 108.1 ?
    C14 C18 Br1 . . 112.7(2) y
    C14 C18 H18A . . 109.1 ?
    Br1 C18 H18A . . 109.1 ?
    C14 C18 H18B . . 109.1 ?
    Br1 C18 H18B . . 109.1 ?
    H18A C18 H18B . . 107.8 ?
    C4 C5 C6 . . 119.9(5) ?
    C4 C5 H5 . . 120.0 ?
    C6 C5 H5 . . 120.0 ?
    O1 C8 C9 . . 115.0(5) ?
    O1 C8 C17 . . 107.0(3) ?
    C9 C8 C17 . . 115.4(4) ?
    O1 C8 C13 . . 103.3(3) ?
    C9 C8 C13 . . 102.0(3) ?
    C17 C8 C13 . . 113.6(5) ?
    C14 C15 H15A . . 109.5 ?
    C14 C15 H15B . . 109.5 ?
    H15A C15 H15B . . 109.5 ?
    C14 C15 H15C . . 109.5 ?
    H15A C15 H15C . . 109.5 ?
    H15B C15 H15C . . 109.5 ?
    C10 C14 C18 . . 115.5(3) ?
    C10 C14 C15 . . 115.8(3) ?
    C18 C14 C15 . . 106.6(3) ?
    C10 C14 C13 . . 93.5(3) ?
    C18 C14 C13 . . 108.2(3) ?
    C15 C14 C13 . . 116.9(3) ?
    C16 C13 C12 . . 113.9(3) ?
    C16 C13 C8 . . 116.2(4) ?
    C12 C13 C8 . . 105.7(3) ?
    C16 C13 C14 . . 117.5(3) ?
    C12 C13 C14 . . 100.2(3) ?
    C8 C13 C14 . . 101.3(3) ?
    C11 C12 C13 . . 104.3(3) ?
    C11 C12 H12A . . 110.9 ?
    C13 C12 H12A . . 110.9 ?
    C11 C12 H12B . . 110.9 ?
    C13 C12 H12B . . 110.9 ?
    H12A C12 H12B . . 108.9 ?
    C9 C10 C14 . . 102.4(3) ?
    C9 C10 C11 . . 107.3(3) ?
    C14 C10 C11 . . 103.0(3) ?
    C9 C10 H10 . . 114.3 ?
    C14 C10 H10 . . 114.3 ?
    C11 C10 H10 . . 114.3 ?
    C10 C9 C8 . . 105.8(4) y
    C10 C9 H9A . . 110.6 ?
    C8 C9 H9A . . 110.6 ?
    C10 C9 H9B . . 110.6 ?
    C8 C9 H9B . . 110.6 ?
    H9A C9 H9B . . 108.7 ?
    C8 C17 H17A . . 109.5 ?
    C8 C17 H17B . . 109.5 ?
    H17A C17 H17B . . 109.5 ?
    C8 C17 H17C . . 109.5 ?
    H17A C17 H17C . . 109.5 ?
    H17B C17 H17C . . 109.5 ?
    C12 C11 C10 . . 102.8(3) y
    C12 C11 H11A . . 111.2 ?
    C10 C11 H11A . . 111.2 ?
    C12 C11 H11B . . 111.2 ?
    C10 C11 H11B . . 111.2 ?
    H11A C11 H11B . . 109.1 ?
    C13 C16 H16A . . 109.5 ?
    C13 C16 H16B . . 109.5 ?
    H16A C16 H16B . . 109.5 ?
    C13 C16 H16C . . 109.5 ?
    H16A C16 H16C . . 109.5 ?
    H16B C16 H16C . . 109.5 ?
    C7 O1 C8 . . 117.3(3) y
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
    C6 C1 C2 C3 . . . . -2.4(8) ?
    C7 C1 C2 C3 . . . . -178.8(5) ?
    C1 C2 C3 C4 . . . . 0.7(9) ?
    C2 C3 C4 C5 . . . . 2.0(9) ?
    C2 C1 C6 C5 . . . . 1.5(9) ?
    C7 C1 C6 C5 . . . . 177.9(5) ?
    C2 C1 C7 O1 . . . . -116.7(6) ?
    C6 C1 C7 O1 . . . . 67.0(8) ?
    C3 C4 C5 C6 . . . . -2.9(10) ?
    C1 C6 C5 C4 . . . . 1.2(10) ?
    Br1 C18 C14 C10 . . . . -60.3(3) ?
    Br1 C18 C14 C15 . . . . 70.0(3) ?
    Br1 C18 C14 C13 . . . . -163.4(2) ?
    O1 C8 C13 C16 . . . . 79.7(4) ?
    C9 C8 C13 C16 . . . . -160.7(3) ?
    C17 C8 C13 C16 . . . . -35.8(4) ?
    O1 C8 C13 C12 . . . . -47.7(4) ?
    C9 C8 C13 C12 . . . . 71.9(3) ?
    C17 C8 C13 C12 . . . . -163.2(3) ?
    O1 C8 C13 C14 . . . . -151.8(3) ?
    C9 C8 C13 C14 . . . . -32.2(3) ?
    C17 C8 C13 C14 . . . . 92.7(4) ?
    C10 C14 C13 C16 . . . . -178.9(3) ?
    C18 C14 C13 C16 . . . . -60.6(4) ?
    C15 C14 C13 C16 . . . . 59.7(5) ?
    C10 C14 C13 C12 . . . . -55.0(3) ?
    C18 C14 C13 C12 . . . . 63.3(3) ?
    C15 C14 C13 C12 . . . . -176.4(3) ?
    C10 C14 C13 C8 . . . . 53.4(3) ?
    C18 C14 C13 C8 . . . . 171.7(3) ?
    C15 C14 C13 C8 . . . . -67.9(4) ?
    C16 C13 C12 C11 . . . . 161.3(3) ?
    C8 C13 C12 C11 . . . . -69.9(4) ?
    C14 C13 C12 C11 . . . . 35.0(3) ?
    C18 C14 C10 C9 . . . . -167.5(3) ?
    C15 C14 C10 C9 . . . . 66.8(4) ?
    C13 C14 C10 C9 . . . . -55.4(3) ?
    C18 C14 C10 C11 . . . . -56.2(4) ?
    C15 C14 C10 C11 . . . . 178.1(3) ?
    C13 C14 C10 C11 . . . . 55.9(3) ?
    C14 C10 C9 C8 . . . . 38.0(4) ?
    C11 C10 C9 C8 . . . . -70.0(4) ?
    O1 C8 C9 C10 . . . . 108.8(4) ?
    C17 C8 C9 C10 . . . . -125.9(4) ?
    C13 C8 C9 C10 . . . . -2.2(4) ?
    C13 C12 C11 C10 . . . . -0.7(3) ?
    C9 C10 C11 C12 . . . . 71.6(4) ?
    C14 C10 C11 C12 . . . . -36.1(3) ?
    C1 C7 O1 C8 . . . . -168.4(5) ?
    C9 C8 O1 C7 . . . . 72.2(5) ?
    C17 C8 O1 C7 . . . . -57.5(7) ?
    C13 C8 O1 C7 . . . . -177.6(5) ?
