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_4134076
_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_absolute_configuration ad
_chemical_formula_sum            'C20 H28 O2'
_chemical_formula_weight         300.42
_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     dual
_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                   12.2894(2)
_cell_length_b                   8.57810(10)
_cell_length_c                   16.1793(2)
_cell_measurement_reflns_used    12064
_cell_measurement_temperature    180.00(12)
_cell_measurement_theta_max      72.9110
_cell_measurement_theta_min      3.6060
_cell_volume                     1705.62(4)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      180.00(12)
_diffrn_detector                 'CCD plate'
_diffrn_detector_type            HyPix
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy R, DW system, HyPix'
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0395
_diffrn_reflns_av_unetI/netI     0.0298
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 1.000
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            14636
_diffrn_reflns_point_group_measured_fraction_full 0.959
_diffrn_reflns_point_group_measured_fraction_max 0.959
_diffrn_reflns_theta_full        66.578
_diffrn_reflns_theta_max         66.578
_diffrn_reflns_theta_min         5.156
_diffrn_source                   'fine-focus sealed X-ray tube'
_diffrn_source_type              'Enhance Ultra (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    0.569
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.68091
_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    1.170
_exptl_crystal_description       rod-like
_exptl_crystal_F_000             656
_exptl_crystal_size_max          0.34
_exptl_crystal_size_mid          0.08
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.151
_refine_diff_density_min         -0.146
_refine_diff_density_rms         0.034
_refine_ls_abs_structure_details
;
 Flack x determined using 1244 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.05(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.057
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     203
_refine_ls_number_reflns         2883
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.056
_refine_ls_R_factor_all          0.0328
_refine_ls_R_factor_gt           0.0321
_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^)+(0.0609P)^2^+0.0761P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0866
_refine_ls_wR_factor_ref         0.0873
_reflns_Friedel_coverage         0.843
_reflns_Friedel_fraction_full    0.914
_reflns_Friedel_fraction_max     0.914
_reflns_number_gt                2803
_reflns_number_total             2883
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ja9b13722_si_002.cif
_cod_data_source_block           3
_cod_database_code               4134076
_shelx_shelxl_version_number     2014/7
_shelx_res_checksum              11781
_shelx_hkl_checksum              16614