Convergent Route to ent-Kaurane Diterpenoids: Total Synthesis of Lungshengenin D and 1α,6α-Diacetoxy-ent-kaura-9(11),16-dien-12,15-dione.
Zhao, Xiangbo; Li, Wu; Wang, Junjie; Ma, Dawei; Journal of the American Chemical Society 139 (2017) 2932–2935; doi:10.1021/jacs.7b00140

data_4125662
_publ_section_title
;
 Convergent Route to ent-Kaurane Diterpenoids: Total Synthesis of
 Lungshengenin D and
 1\a,6\a-Diacetoxy-ent-kaura-9(11),16-dien-12,15-dione.
;
_journal_issue                   8
_journal_name_full               'Journal of the American Chemical Society'
_journal_page_first              2932
_journal_page_last               2935
_journal_paper_doi               10.1021/jacs.7b00140
_journal_volume                  139
_journal_year                    2017
_chemical_absolute_configuration ad
_chemical_formula_sum            'C23 H32 Cl2 O4'
_chemical_formula_weight         443.38
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2013
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.4292(18)
_cell_length_b                   12.851(3)
_cell_length_c                   23.312(6)
_cell_measurement_reflns_used    1122
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      38.726
_cell_measurement_theta_min      4.718
_cell_volume                     2225.7(9)
_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-2013 (Sheldrick, 2013)'
_computing_structure_solution    'Bruker SHELXTL'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.978
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0975
_diffrn_reflns_av_unetI/netI     0.0935
_diffrn_reflns_Laue_measured_fraction_full 0.978
_diffrn_reflns_Laue_measured_fraction_max 0.998
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       15
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -26
_diffrn_reflns_number            12362
_diffrn_reflns_point_group_measured_fraction_full 0.977
_diffrn_reflns_point_group_measured_fraction_max 0.999
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         24.998
_diffrn_reflns_theta_min         1.809
_exptl_absorpt_coefficient_mu    0.318
_exptl_absorpt_correction_T_max  0.7456
_exptl_absorpt_correction_T_min  0.5541
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.323
_exptl_crystal_description       prismatic
_exptl_crystal_F_000             944
_exptl_crystal_size_max          0.200
_exptl_crystal_size_mid          0.160
_exptl_crystal_size_min          0.120
_refine_diff_density_max         0.177
_refine_diff_density_min         -0.247
_refine_diff_density_rms         0.042
_refine_ls_abs_structure_details
; 
 Flack x determined using 734 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons and Flack (2004), Acta Cryst. A60, s61). 
;
_refine_ls_abs_structure_Flack   -0.08(9)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.999
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     266
_refine_ls_number_reflns         3924
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.999
_refine_ls_R_factor_all          0.1040
_refine_ls_R_factor_gt           0.0581
_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^)+(0.0666P)^2^+0.1781P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1301
_refine_ls_wR_factor_ref         0.1482
_reflns_Friedel_coverage         0.735
_reflns_Friedel_fraction_full    0.977
_reflns_Friedel_fraction_max     1.000
_reflns_number_gt                2467
_reflns_number_total             3924
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja7b00140_si_004.cif
_cod_data_source_block           cd16504
_cod_original_cell_volume        2225.7(10)
_cod_database_code               4125662
_shelx_estimated_absorpt_t_min   0.939
_shelx_estimated_absorpt_t_max   0.963
_shelxl_version_number           2013-4
_shelx_res_checksum              86429
_shelx_hkl_checksum              55531