Brønsted Acid-Catalyzed, Diastereo- and Enantioselective, Intramolecular Oxa-Diels-Alder Reaction of ortho-Quinone Methides and Unactivated Dienophiles.
Ukis, Rostyslav; Schneider, Christoph; The Journal of organic chemistry 84 (2019) 7175–7188; doi:10.1021/acs.joc.9b00860

data_4034580
_publ_section_title
;
 Br\/onsted Acid-Catalyzed, Diastereo- and Enantioselective,
 Intramolecular Oxa-Diels-Alder Reaction of ortho-Quinone Methides and
 Unactivated Dienophiles.
;
_journal_issue                   11
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              7175
_journal_page_last               7188
_journal_paper_doi               10.1021/acs.joc.9b00860
_journal_volume                  84
_journal_year                    2019
_chemical_formula_sum            'C24 H22 O2'
_chemical_formula_weight         342.41
_space_group_crystal_system      orthorhombic
_space_group_IT_number           29
_space_group_name_Hall           'P 2c -2ac'
_space_group_name_H-M_alt        'P c a 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   11.4273(2)
_cell_length_b                   12.1982(2)
_cell_length_c                   12.8395(2)
_cell_measurement_reflns_used    55265
_cell_measurement_temperature    180(2)
_cell_measurement_theta_max      70.87
_cell_measurement_theta_min      3.62
_cell_volume                     1789.73(5)
_computing_cell_refinement       'Stoe X-Area'
_computing_data_collection       'Stoe X-Area'
_computing_data_reduction        'Stoe X-Area'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    SHELXS
_diffrn_ambient_temperature      180(2)
_diffrn_detector_area_resol_mean 5.81
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'STOE STADIVARI'
_diffrn_measurement_method       'rotation method, \w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54186
_diffrn_reflns_av_R_equivalents  0.0334
_diffrn_reflns_av_unetI/netI     0.0124
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -11
_diffrn_reflns_number            47098
_diffrn_reflns_point_group_measured_fraction_full 0.850
_diffrn_reflns_point_group_measured_fraction_max 0.838
_diffrn_reflns_theta_full        67.686
_diffrn_reflns_theta_max         70.642
_diffrn_reflns_theta_min         3.624
_diffrn_source                   'GeniX 3D HF Cu'
_exptl_absorpt_coefficient_mu    0.621
_exptl_absorpt_correction_T_max  0.9816
_exptl_absorpt_correction_T_min  0.9144
_exptl_absorpt_correction_type   integration
_exptl_absorpt_process_details
;
STOE X-Red32, absorption correction by Gaussian integration, analogous to
P. Coppens, "The Evaluation of Absorption and Extinction in Single-Crystal
Structure Analysis", published in
F. R. Ahmed (Editor), "Crystallographic Computing",
Munksgaard, Copenhagen (1970), 255 - 270
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.271
_exptl_crystal_description       rod
_exptl_crystal_F_000             728
_exptl_crystal_size_max          0.200
_exptl_crystal_size_mid          0.060
_exptl_crystal_size_min          0.030
_refine_diff_density_max         0.186
_refine_diff_density_min         -0.098
_refine_diff_density_rms         0.026
_refine_ls_abs_structure_details
;
 Flack x determined using 990 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.10(18)
_refine_ls_extinction_coef       0.0015(3)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2014/7 (Sheldrick 2014'
_refine_ls_goodness_of_fit_ref   1.052
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     238
_refine_ls_number_reflns         2879
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.052
_refine_ls_R_factor_all          0.0298
_refine_ls_R_factor_gt           0.0288
_refine_ls_shift/su_max          0.018
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0528P)^2^+0.2006P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0800
_refine_ls_wR_factor_ref         0.0806
_reflns_Friedel_coverage         0.599
_reflns_Friedel_fraction_full    0.684
_reflns_Friedel_fraction_max     0.660
_reflns_number_gt                2763
_reflns_number_total             2879
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo9b00860_si_003.cif
_cod_data_source_block           sv0316b
_cod_database_code               4034580
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.886
_shelx_estimated_absorpt_t_max   0.982
_shelx_res_checksum              16475
_shelx_hkl_checksum              3524