#------------------------------------------------------------------------------
#$Date: 2016-03-21 03:07:09 +0200 (Mon, 21 Mar 2016) $
#$Revision: 178421 $
#$URL: svn://www.crystallography.net/cod/cif/4/02/42/4024257.cif $
#------------------------------------------------------------------------------
#
# This file is available in the Crystallography Open Database (COD),
# http://www.crystallography.net/
#
# All data on this site have been placed in the public domain by the
# contributors.
#
data_4024257
loop_
_publ_author_name
'Weimin Lin'
'Cory R. Theberge'
'Timothy J. Henderson'
'Charles K. Zercher'
'Jerry Jasinski'
'Ray. J. Butcher'
_publ_section_title
;
Stereoselective Formation of a Functionalized Dipeptide Isostere by Zinc
Carbenoid-Mediated Chain Extension
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              645
_journal_page_last               651
_journal_paper_doi               10.1021/jo801993k
_journal_volume                  74
_journal_year                    2009
_chemical_formula_moiety         'C23 H23 N O5'
_chemical_formula_sum            'C23 H23 N O5'
_chemical_formula_weight         393.42
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           29
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2ac'
_symmetry_space_group_name_H-M   'P c a 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   9.4862(16)
_cell_length_b                   8.3879(14)
_cell_length_c                   24.325(4)
_cell_measurement_temperature    103(2)
_cell_volume                     1935.6(6)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      103(2)
_diffrn_measured_fraction_theta_full 0.948
_diffrn_measured_fraction_theta_max 0.948
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'φ and ω'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0304
_diffrn_reflns_av_sigmaI/netI    0.0248
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       31
_diffrn_reflns_limit_l_min       -31
_diffrn_reflns_number            14924
_diffrn_reflns_theta_full        29.18
_diffrn_reflns_theta_max         29.18
_diffrn_reflns_theta_min         1.67
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.095
_exptl_absorpt_correction_T_max  0.972
_exptl_absorpt_correction_T_min  0.948
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   '(SADABS; Sheldrick, 1996)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.350
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       chunk
_exptl_crystal_F_000             832
_exptl_crystal_size_max          0.55
_exptl_crystal_size_mid          0.45
_exptl_crystal_size_min          0.30
_refine_diff_density_max         0.339
_refine_diff_density_min         -0.166
_refine_diff_density_rms         0.048
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.5(6)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.043
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     263
_refine_ls_number_reflns         4696
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.042
_refine_ls_R_factor_all          0.0382
_refine_ls_R_factor_gt           0.0346
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[σ²(Fo²)+(0.0656P)²+0.0249P] where P=(Fo²+2Fc²)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0883
_refine_ls_wR_factor_ref         0.0906
_reflns_number_gt                4358
_reflns_number_total             4696
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo801993k_si_003.cif
_cod_data_source_block           jerry16m
_cod_depositor_comments
;
The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Orthorhombic' changed to 'orthorhombic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 
;
_cod_database_code               4024257
loop_
_symmetry_equiv_pos_as_xyz
'x, y, z'
'-x, -y, z+1/2'
'x+1/2, -y, z'
'-x+1/2, y, z+1/2'
loop_
_atom_site_label
_atom_site_type_symbol
_atom_site_fract_x
_atom_site_fract_y
_atom_site_fract_z
_atom_site_U_iso_or_equiv
_atom_site_adp_type
_atom_site_occupancy
_atom_site_symmetry_multiplicity
_atom_site_calc_flag
_atom_site_refinement_flags
_atom_site_disorder_assembly
_atom_site_disorder_group
O1 O 0.42009(9) 0.31044(11) 0.37759(4) 0.01712(19) Uani 1 1 d . . .
H1A H 0.4559 0.2190 0.3759 0.026 Uiso 1 1 calc R . .
O8 O 0.04495(11) -0.02097(12) 0.38360(5) 0.0274(2) Uani 1 1 d . . .
O13 O 0.03171(10) 0.44412(13) 0.49254(4) 0.0246(2) Uani 1 1 d . . .
O161 O 0.40153(10) 0.67463(11) 0.35675(4) 0.0211(2) Uani 1 1 d . . .
O162 O 0.27459(10) 0.60013(12) 0.28283(4) 0.0194(2) Uani 1 1 d . . .
N N 0.19129(11) 0.19556(13) 0.39427(5) 0.0172(2) Uani 1 1 d . . .
C1 C 0.27875(12) 0.30369(15) 0.36025(5) 0.0147(2) Uani 1 1 d . . .
C2 C 0.26227(13) 0.22877(15) 0.30355(6) 0.0174(2) Uani 1 1 d . . .
C3 C 0.32789(15) 0.26572(17) 0.25437(6) 0.0210(3) Uani 1 1 d . . .
H3A H 0.3943 0.3503 0.2523 0.025 Uiso 1 1 calc R . .
C4 C 0.29418(16) 0.17561(18) 0.20780(6) 0.0262(3) Uani 1 1 d . . .
H4A H 0.3366 0.2010 0.1735 0.031 Uiso 1 1 calc R . .
C5 C 0.19914(17) 0.04904(18) 0.21098(7) 0.0279(3) Uani 1 1 d . . .
H5A H 0.1766 -0.0100 0.1788 0.033 Uiso 1 1 calc R . .
C6 C 0.13715(15) 0.00867(18) 0.26090(7) 0.0258(3) Uani 1 1 d . . .
H6A H 0.0737 -0.0786 0.2635 0.031 Uiso 1 1 calc R . .
C7 C 0.17060(14) 0.09923(15) 0.30658(6) 0.0195(3) Uani 1 1 d . . .
C8 C 0.12527(13) 0.07980(16) 0.36442(6) 0.0200(3) Uani 1 1 d . . .
C9 C 0.15532(14) 0.22702(16) 0.45189(5) 0.0191(3) Uani 1 1 d . . .
H9A H 0.0678 0.1654 0.4605 0.023 Uiso 1 1 calc R . .
C10 C 0.27222(15) 0.16933(19) 0.49207(6) 0.0240(3) Uani 1 1 d . . .
H10A H 0.3616 0.2278 0.4838 0.029 Uiso 1 1 calc R . .
C11 C 0.29663(19) -0.0089(2) 0.48356(7) 0.0342(4) Uani 1 1 d . . .
H11A H 0.3702 -0.0459 0.5088 0.051 Uiso 1 1 calc R . .
H11B H 0.3263 -0.0282 0.4456 0.051 Uiso 1 1 calc R . .
H11C H 0.2090 -0.0670 0.4909 0.051 Uiso 1 1 calc R . .
C12 C 0.22998(18) 0.2022(2) 0.55189(6) 0.0314(3) Uani 1 1 d . . .
H12A H 0.3049 0.1651 0.5765 0.047 Uiso 1 1 calc R . .
H12B H 0.1423 0.1455 0.5603 0.047 Uiso 1 1 calc R . .
H12C H 0.2158 0.3170 0.5570 0.047 Uiso 1 1 calc R . .
C13 C 0.12150(13) 0.40240(16) 0.45968(5) 0.0182(2) Uani 1 1 d . . .
C14 C 0.20903(13) 0.52058(15) 0.42759(6) 0.0179(2) Uani 1 1 d . . .
H14A H 0.3052 0.5249 0.4433 0.021 Uiso 1 1 calc R . .
H14B H 0.1667 0.6280 0.4310 0.021 Uiso 1 1 calc R . .
C15 C 0.21814(12) 0.47506(15) 0.36659(5) 0.0145(2) Uani 1 1 d . . .
H15A H 0.1212 0.4777 0.3505 0.017 Uiso 1 1 calc R . .
C16 C 0.30950(13) 0.59494(15) 0.33647(5) 0.0158(2) Uani 1 1 d . . .
C17 C 0.36855(14) 0.69144(16) 0.24784(5) 0.0191(3) Uani 1 1 d . . .
H17A H 0.4660 0.6504 0.2511 0.023 Uiso 1 1 calc R . .
H17B H 0.3681 0.8049 0.2591 0.023 Uiso 1 1 calc R . .
C18 C 0.31822(14) 0.67581(16) 0.18939(6) 0.0187(3) Uani 1 1 d . . .
C19 C 0.41087(16) 0.7140(2) 0.14694(6) 0.0258(3) Uani 1 1 d . . .
H19A H 0.5051 0.7436 0.1553 0.031 Uiso 1 1 calc R . .
C20 C 0.36665(18) 0.7092(2) 0.09236(6) 0.0319(3) Uani 1 1 d . . .
H20A H 0.4304 0.7369 0.0638 0.038 Uiso 1 1 calc R . .
C21 C 0.22949(17) 0.66394(19) 0.07953(6) 0.0276(3) Uani 1 1 d . . .
H21A H 0.1992 0.6601 0.0423 0.033 Uiso 1 1 calc R . .
C22 C 0.13763(16) 0.62455(19) 0.12154(7) 0.0283(3) Uani 1 1 d . . .
H22A H 0.0437 0.5939 0.1131 0.034 Uiso 1 1 calc R . .
C23 C 0.18158(15) 0.62947(19) 0.17614(6) 0.0252(3) Uani 1 1 d . . .
H23A H 0.1177 0.6010 0.2046 0.030 Uiso 1 1 calc R . .
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'
N N 0.0061 0.0033 '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'
loop_
_geom_angle_atom_site_label_1
_geom_angle_atom_site_label_2
_geom_angle_atom_site_label_3
_geom_angle
_geom_angle_site_symmetry_1
_geom_angle_site_symmetry_3
_geom_angle_publ_flag
C1 O1 H1A 109.5 . . ?
C16 O162 C17 115.74(10) . . ?
C8 N C9 121.99(11) . . ?
C8 N C1 113.29(11) . . ?
C9 N C1 123.63(10) . . ?
O1 C1 N 113.00(10) . . ?
O1 C1 C2 112.69(10) . . ?
N C1 C2 101.28(10) . . ?
O1 C1 C15 106.58(9) . . ?
N C1 C15 107.66(9) . . ?
C2 C1 C15 115.65(10) . . ?
C3 C2 C7 120.07(12) . . ?
C3 C2 C1 130.09(12) . . ?
C7 C2 C1 109.74(12) . . ?
C2 C3 C4 118.44(13) . . ?
C2 C3 H3A 120.8 . . ?
C4 C3 H3A 120.8 . . ?
C5 C4 C3 120.93(15) . . ?
C5 C4 H4A 119.5 . . ?
C3 C4 H4A 119.5 . . ?
C6 C5 C4 120.46(14) . . ?
C6 C5 H5A 119.8 . . ?
C4 C5 H5A 119.8 . . ?
C7 C6 C5 118.08(14) . . ?
C7 C6 H6A 121.0 . . ?
C5 C6 H6A 121.0 . . ?
C6 C7 C2 121.94(14) . . ?
C6 C7 C8 129.54(13) . . ?
C2 C7 C8 108.50(12) . . ?
O8 C8 N 124.86(14) . . ?
O8 C8 C7 128.04(13) . . ?
N C8 C7 107.10(11) . . ?
N C9 C13 110.06(10) . . ?
N C9 C10 112.26(11) . . ?
C13 C9 C10 111.95(12) . . ?
N C9 H9A 107.4 . . ?
C13 C9 H9A 107.4 . . ?
C10 C9 H9A 107.4 . . ?
C11 C10 C12 110.13(12) . . ?
C11 C10 C9 109.13(13) . . ?
C12 C10 C9 110.73(11) . . ?
C11 C10 H10A 108.9 . . ?
C12 C10 H10A 108.9 . . ?
C9 C10 H10A 108.9 . . ?
C10 C11 H11A 109.5 . . ?
C10 C11 H11B 109.5 . . ?
H11A C11 H11B 109.5 . . ?
C10 C11 H11C 109.5 . . ?
H11A C11 H11C 109.5 . . ?
H11B C11 H11C 109.5 . . ?
C10 C12 H12A 109.5 . . ?
C10 C12 H12B 109.5 . . ?
H12A C12 H12B 109.5 . . ?
C10 C12 H12C 109.5 . . ?
H12A C12 H12C 109.5 . . ?
H12B C12 H12C 109.5 . . ?
O13 C13 C14 122.31(12) . . ?
O13 C13 C9 120.51(12) . . ?
C14 C13 C9 117.09(11) . . ?
C13 C14 C15 111.56(10) . . ?
C13 C14 H14A 109.3 . . ?
C15 C14 H14A 109.3 . . ?
C13 C14 H14B 109.3 . . ?
C15 C14 H14B 109.3 . . ?
H14A C14 H14B 108.0 . . ?
C16 C15 C14 109.53(10) . . ?
C16 C15 C1 110.71(9) . . ?
C14 C15 C1 110.28(10) . . ?
C16 C15 H15A 108.8 . . ?
C14 C15 H15A 108.8 . . ?
C1 C15 H15A 108.8 . . ?
O161 C16 O162 123.83(12) . . ?
O161 C16 C15 125.74(12) . . ?
O162 C16 C15 110.42(10) . . ?
O162 C17 C18 108.25(10) . . ?
O162 C17 H17A 110.0 . . ?
C18 C17 H17A 110.0 . . ?
O162 C17 H17B 110.0 . . ?
C18 C17 H17B 110.0 . . ?
H17A C17 H17B 108.4 . . ?
C23 C18 C19 118.71(14) . . ?
C23 C18 C17 122.59(12) . . ?
C19 C18 C17 118.67(12) . . ?
C20 C19 C18 120.65(14) . . ?
C20 C19 H19A 119.7 . . ?
C18 C19 H19A 119.7 . . ?
C21 C20 C19 120.23(14) . . ?
C21 C20 H20A 119.9 . . ?
C19 C20 H20A 119.9 . . ?
C22 C21 C20 119.26(14) . . ?
C22 C21 H21A 120.4 . . ?
C20 C21 H21A 120.4 . . ?
C21 C22 C23 120.59(14) . . ?
C21 C22 H22A 119.7 . . ?
C23 C22 H22A 119.7 . . ?
C18 C23 C22 120.55(14) . . ?
C18 C23 H23A 119.7 . . ?
C22 C23 H23A 119.7 . . ?
loop_
_geom_bond_atom_site_label_1
_geom_bond_atom_site_label_2
_geom_bond_distance
_geom_bond_site_symmetry_2
_geom_bond_publ_flag
O1 C1 1.4067(14) . ?
O1 H1A 0.8400 . ?
O8 C8 1.2298(17) . ?
O13 C13 1.2194(17) . ?
O161 C16 1.2051(16) . ?
O162 C16 1.3470(16) . ?
O162 C17 1.4510(15) . ?
N C8 1.3646(17) . ?
N C9 1.4666(17) . ?
N C1 1.4818(16) . ?
C1 C2 1.5237(18) . ?
C1 C15 1.5558(16) . ?
C2 C3 1.3838(19) . ?
C2 C7 1.3936(19) . ?
C3 C4 1.399(2) . ?
C3 H3A 0.9500 . ?
C4 C5 1.395(2) . ?
C4 H4A 0.9500 . ?
C5 C6 1.391(2) . ?
C5 H5A 0.9500 . ?
C6 C7 1.383(2) . ?
C6 H6A 0.9500 . ?
C7 C8 1.480(2) . ?
C9 C13 1.5175(19) . ?
C9 C10 1.5553(19) . ?
C9 H9A 1.0000 . ?
C10 C11 1.527(2) . ?
C10 C12 1.534(2) . ?
C10 H10A 1.0000 . ?
C11 H11A 0.9800 . ?
C11 H11B 0.9800 . ?
C11 H11C 0.9800 . ?
C12 H12A 0.9800 . ?
C12 H12B 0.9800 . ?
C12 H12C 0.9800 . ?
C13 C14 1.5105(18) . ?
C14 C15 1.5346(18) . ?
C14 H14A 0.9900 . ?
C14 H14B 0.9900 . ?
C15 C16 1.5162(17) . ?
C15 H15A 1.0000 . ?
C17 C18 1.5056(19) . ?
C17 H17A 0.9900 . ?
C17 H17B 0.9900 . ?
C18 C23 1.3911(19) . ?
C18 C19 1.393(2) . ?
C19 C20 1.393(2) . ?
C19 H19A 0.9500 . ?
C20 C21 1.391(2) . ?
C20 H20A 0.9500 . ?
C21 C22 1.383(2) . ?
C21 H21A 0.9500 . ?
C22 C23 1.393(2) . ?
C22 H22A 0.9500 . ?
C23 H23A 0.9500 . ?
loop_
_geom_hbond_atom_site_label_D
_geom_hbond_atom_site_label_H
_geom_hbond_atom_site_label_A
_geom_hbond_distance_DH
_geom_hbond_distance_HA
_geom_hbond_distance_DA
_geom_hbond_angle_DHA
_geom_hbond_site_symmetry_A
O1 H1A O8 0.84 1.87 2.7056(13) 170.8 3
C14 H14A O13 0.99 2.47 3.4575(17) 172.5 3_565
C15 H15A O161 1.00 2.45 3.2641(16) 138.3 3_465
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
_geom_torsion_site_symmetry_1
_geom_torsion_site_symmetry_2
_geom_torsion_site_symmetry_3
_geom_torsion_site_symmetry_4
_geom_torsion_publ_flag
C8 N C1 O1 -123.86(12) . . . . ?
C9 N C1 O1 67.88(15) . . . . ?
C8 N C1 C2 -3.06(13) . . . . ?
C9 N C1 C2 -171.32(11) . . . . ?
C8 N C1 C15 118.73(11) . . . . ?
C9 N C1 C15 -49.53(15) . . . . ?
O1 C1 C2 C3 -52.77(18) . . . . ?
N C1 C2 C3 -173.79(13) . . . . ?
C15 C1 C2 C3 70.18(17) . . . . ?
O1 C1 C2 C7 123.55(11) . . . . ?
N C1 C2 C7 2.53(13) . . . . ?
C15 C1 C2 C7 -113.50(12) . . . . ?
C7 C2 C3 C4 3.29(19) . . . . ?
C1 C2 C3 C4 179.28(12) . . . . ?
C2 C3 C4 C5 -1.5(2) . . . . ?
C3 C4 C5 C6 -0.8(2) . . . . ?
C4 C5 C6 C7 1.2(2) . . . . ?
C5 C6 C7 C2 0.7(2) . . . . ?
C5 C6 C7 C8 -177.39(13) . . . . ?
C3 C2 C7 C6 -3.0(2) . . . . ?
C1 C2 C7 C6 -179.73(12) . . . . ?
C3 C2 C7 C8 175.46(11) . . . . ?
C1 C2 C7 C8 -1.29(14) . . . . ?
C9 N C8 O8 -9.8(2) . . . . ?
C1 N C8 O8 -178.29(12) . . . . ?
C9 N C8 C7 170.91(11) . . . . ?
C1 N C8 C7 2.44(14) . . . . ?
C6 C7 C8 O8 -1.6(2) . . . . ?
C2 C7 C8 O8 -179.89(13) . . . . ?
C6 C7 C8 N 177.63(14) . . . . ?
C2 C7 C8 N -0.65(14) . . . . ?
C8 N C9 C13 -126.82(12) . . . . ?
C1 N C9 C13 40.45(16) . . . . ?
C8 N C9 C10 107.76(14) . . . . ?
C1 N C9 C10 -84.97(14) . . . . ?
N C9 C10 C11 -57.87(15) . . . . ?
C13 C9 C10 C11 177.76(12) . . . . ?
N C9 C10 C12 -179.24(12) . . . . ?
C13 C9 C10 C12 56.39(16) . . . . ?
N C9 C13 O13 145.45(12) . . . . ?
C10 C9 C13 O13 -88.96(15) . . . . ?
N C9 C13 C14 -37.89(15) . . . . ?
C10 C9 C13 C14 87.70(14) . . . . ?
O13 C13 C14 C15 -134.22(13) . . . . ?
C9 C13 C14 C15 49.18(15) . . . . ?
C13 C14 C15 C16 -178.75(10) . . . . ?
C13 C14 C15 C1 -56.67(13) . . . . ?
O1 C1 C15 C16 53.96(13) . . . . ?
N C1 C15 C16 175.47(10) . . . . ?
C2 C1 C15 C16 -72.17(13) . . . . ?
O1 C1 C15 C14 -67.43(12) . . . . ?
N C1 C15 C14 54.08(12) . . . . ?
C2 C1 C15 C14 166.45(10) . . . . ?
C17 O162 C16 O161 8.81(18) . . . . ?
C17 O162 C16 C15 -170.69(10) . . . . ?
C14 C15 C16 O161 25.86(17) . . . . ?
C1 C15 C16 O161 -95.96(15) . . . . ?
C14 C15 C16 O162 -154.65(10) . . . . ?
C1 C15 C16 O162 83.53(12) . . . . ?
C16 O162 C17 C18 176.68(11) . . . . ?
O162 C17 C18 C23 19.85(18) . . . . ?
O162 C17 C18 C19 -162.18(13) . . . . ?
C23 C18 C19 C20 1.4(2) . . . . ?
C17 C18 C19 C20 -176.69(14) . . . . ?
C18 C19 C20 C21 -0.9(3) . . . . ?
C19 C20 C21 C22 0.3(3) . . . . ?
C20 C21 C22 C23 -0.2(2) . . . . ?
C19 C18 C23 C22 -1.3(2) . . . . ?
C17 C18 C23 C22 176.69(14) . . . . ?
C21 C22 C23 C18 0.7(2) . . . . ?
