Protecting-Group-Free Syntheses of <i>ent</i>-Kaurane Diterpenoids: [3+2+1] Cycloaddition/Cycloalkenylation Approach.
Wang, Jin; Hong, Benke; Hu, Dachao; Kadonaga, Yuichiro; Tang, Ruyao; Lei, Xiaoguang; Journal of the American Chemical Society  (2020) –; doi:10.1021/jacs.9b13722

data_4134077
_publ_section_title
;
 Protecting-Group-Free Syntheses of <i>ent</i>-Kaurane Diterpenoids:
 [3+2+1] Cycloaddition/Cycloalkenylation Approach.
;
_journal_name_full               'Journal of the American Chemical Society'
_journal_paper_doi               10.1021/jacs.9b13722
_journal_year                    2020
_chemical_formula_sum            'C20 H26 O2'
_chemical_formula_weight         298.41
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 96.003(4)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   7.9564(4)
_cell_length_b                   8.9245(5)
_cell_length_c                   23.0248(10)
_cell_measurement_reflns_used    3755
_cell_measurement_temperature    179.99(10)
_cell_measurement_theta_max      29.4230
_cell_measurement_theta_min      2.4540
_cell_volume                     1625.95(14)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      179.99(10)
_diffrn_detector                 'CCD plate'
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB AFC12 (RINC): Kappa single'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0459
_diffrn_reflns_av_unetI/netI     0.0529
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            11647
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.999
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.484
_diffrn_reflns_theta_min         1.779
_diffrn_source                   'fine-focus sealed X-ray tube'
_diffrn_source_type              'Enhance (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.077
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.52886
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.39.29a (Rigaku Oxford Diffraction, 2015)
Empirical absorption correction using spherical harmonics,
 implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.219
_exptl_crystal_description       rod-like
_exptl_crystal_F_000             648
_exptl_crystal_size_max          0.34
_exptl_crystal_size_mid          0.11
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.592
_refine_diff_density_min         -0.288
_refine_diff_density_rms         0.062
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.002
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     202
_refine_ls_number_reflns         3738
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.002
_refine_ls_R_factor_all          0.0722
_refine_ls_R_factor_gt           0.0546
_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^)+(0.0698P)^2^+0.8488P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1388
_refine_ls_wR_factor_ref         0.1497
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2838
_reflns_number_total             3738
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja9b13722_si_007.cif
_cod_data_source_block           3
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               4134077
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              26937
_shelx_hkl_checksum              80191