Synthesis and Conformational Analysis of Parent Perhydroazulenes Reveals an Energetically Preferred cis Ring Fusion.
Saito, Fumito; Becker, Jonathan; Schreiner, Peter R.; The Journal of organic chemistry  (2020) –; doi:10.1021/acs.joc.0c00167

data_4038032
_publ_section_title
;
 Synthesis and Conformational Analysis of Parent Perhydroazulenes Reveals
 an Energetically Preferred cis Ring Fusion.
;
_journal_name_full               'The Journal of organic chemistry'
_journal_paper_doi               10.1021/acs.joc.0c00167
_journal_year                    2020
_chemical_formula_sum            'C17 H21 N O4'
_chemical_formula_weight         303.35
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2018/3
_cell_angle_alpha                69.1744(14)
_cell_angle_beta                 87.7497(15)
_cell_angle_gamma                81.4656(15)
_cell_formula_units_Z            6
_cell_length_a                   6.8690(3)
_cell_length_b                   18.7339(8)
_cell_length_c                   19.4363(9)
_cell_measurement_reflns_used    9992
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.30
_cell_measurement_theta_min      2.61
_cell_volume                     2311.59(18)
_computing_cell_refinement       'SAINT 8.38A (Bruker-AXS, 2017)'
_computing_data_collection       'APEX3 v2017.3-0 (Bruker-AXS, 2017)'
_computing_data_reduction        'SAINT 8.38A (Bruker-AXS, 2017)'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2018/3 (Sheldrick, 2018)'
_computing_structure_solution    'SHELXT-2015 (Sheldrick, 2015)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 10.4167
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker PHOTON100'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0790
_diffrn_reflns_av_unetI/netI     0.0347
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -23
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            110868
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 1.000
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         26.022
_diffrn_reflns_theta_min         1.306
_diffrn_source
'I\mS micro-focus sealed tube, multilayer optics'
_exptl_absorpt_coefficient_mu    0.093
_exptl_absorpt_correction_T_max  0.7458
_exptl_absorpt_correction_T_min  0.6793
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 2009)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.307
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             972
_exptl_crystal_size_max          0.905
_exptl_crystal_size_mid          0.166
_exptl_crystal_size_min          0.153
_refine_diff_density_max         0.276
_refine_diff_density_min         -0.259
_refine_diff_density_rms         0.047
_refine_ls_extinction_coef       0.0072(6)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2018/3 (Sheldrick 2018)'
_refine_ls_goodness_of_fit_ref   1.020
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     829
_refine_ls_number_reflns         9117
_refine_ls_number_restraints     2997
_refine_ls_restrained_S_all      0.984
_refine_ls_R_factor_all          0.0776
_refine_ls_R_factor_gt           0.0486
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0486P)^2^+1.2501P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1075
_refine_ls_wR_factor_ref         0.1218
_reflns_Friedel_coverage         0.000
_reflns_number_gt                6533
_reflns_number_total             9117
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo0c00167_si_003.cif
_cod_data_source_block           D19315
_cod_database_code               4038032
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_min   0.921
_shelx_estimated_absorpt_t_max   0.986
_shelx_res_checksum              14501
_shelx_hkl_checksum              60804