Synthetic Studies on Enantioselective Total Synthesis of Cyathane Diterpenoids: Cyrneines A and B, Glaucopine C, and (+)-Allocyathin B<sub>2</sub>.
Wu, Guo-Jie; Zhang, Yuan-He; Tan, Dong-Xing; He, Long; Cao, Bao-Chen; He, Yu-Peng; Han, Fu-She; The Journal of organic chemistry 84 (2019) 3223–3238; doi:10.1021/acs.joc.8b03138

data_4033899
_publ_section_title
;
 Synthetic Studies on Enantioselective Total Synthesis of Cyathane
 Diterpenoids: Cyrneines A and B, Glaucopine C, and (+)-Allocyathin
 B<sub>2</sub>.
;
_journal_issue                   6
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              3223
_journal_page_last               3238
_journal_paper_doi               10.1021/acs.joc.8b03138
_journal_volume                  84
_journal_year                    2019
_chemical_absolute_configuration R(C3),R(C6),R(C9),S(C14)
_chemical_formula_moiety         'C20 H28 O3'
_chemical_formula_sum            'C20 H28 O3'
_chemical_formula_weight         316.42
_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'
_atom_sites_solution_hydrogens   geom
_audit_creation_method           SHELXL-2018/1
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.9296(2)
_cell_length_b                   13.6851(3)
_cell_length_c                   18.2162(4)
_cell_measurement_reflns_used    9758
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      72.39
_cell_measurement_theta_min      4.86
_cell_volume                     1727.48(7)
_computing_cell_refinement       'SAINT v8.34A (Bruker, 2013)'
_computing_data_reduction        'SAINT v8.34A (Bruker, 2013)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL-2018/1 (Sheldrick, 2018)'
_computing_structure_solution    'SIR2004 (Burla et al., 2007)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0453
_diffrn_reflns_av_unetI/netI     0.0270
_diffrn_reflns_Laue_measured_fraction_full 0.995
_diffrn_reflns_Laue_measured_fraction_max 0.995
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            22615
_diffrn_reflns_point_group_measured_fraction_full 0.994
_diffrn_reflns_point_group_measured_fraction_max 0.994
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         72.395
_diffrn_reflns_theta_min         4.855
_exptl_absorpt_coefficient_mu    0.632
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            yellow
_exptl_crystal_colour_primary    yellow
_exptl_crystal_density_diffrn    1.217
_exptl_crystal_description       block
_exptl_crystal_F_000             688
_exptl_crystal_size_max          0.400
_exptl_crystal_size_mid          0.300
_exptl_crystal_size_min          0.250
_refine_diff_density_max         0.236
_refine_diff_density_min         -0.216
_refine_diff_density_rms         0.061
_refine_ls_abs_structure_details
;
 Flack x determined using 1344 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   -0.02(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.068
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     214
_refine_ls_number_reflns         3397
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.068
_refine_ls_R_factor_all          0.0366
_refine_ls_R_factor_gt           0.0353
_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^)+(0.0562P)^2^+0.3371P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0921
_refine_ls_wR_factor_ref         0.0936
_reflns_Friedel_coverage         0.725
_reflns_Friedel_fraction_full    0.993
_reflns_Friedel_fraction_max     0.993
_reflns_number_gt                3292
_reflns_number_total             3397
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo8b03138_si_002.cif
_cod_data_source_block           shelx
_cod_database_code               4033899
_shelx_shelxl_version_number     2018/1
_shelx_estimated_absorpt_t_min   0.786
_shelx_estimated_absorpt_t_max   0.858
_shelx_res_checksum              68402
_shelx_hkl_checksum              23313