Development of a Unified Enantioselective, Convergent Synthetic Approach Toward the Furanobutenolide-Derived Polycyclic Norcembranoid Diterpenes: Asymmetric Formation of the Polycyclic Norditerpenoid Carbocyclic Core by Tandem Annulation Cascade.
Craig, 2nd, Robert A; Smith, Russell C.; Roizen, Jennifer L.; Jones, Amanda C.; Virgil, Scott C.; Stoltz, Brian M.; The Journal of organic chemistry 83 (2018) 3467–3485; doi:10.1021/acs.joc.7b02825

data_4035487
_publ_section_title
;
 Development of a Unified Enantioselective, Convergent Synthetic Approach
 Toward the Furanobutenolide-Derived Polycyclic Norcembranoid Diterpenes:
 Asymmetric Formation of the Polycyclic Norditerpenoid Carbocyclic Core by
 Tandem Annulation Cascade.
;
_journal_issue                   7
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              3467
_journal_page_last               3485
_journal_paper_doi               10.1021/acs.joc.7b02825
_journal_volume                  83
_journal_year                    2018
_chemical_absolute_configuration syn
_chemical_formula_sum            'C19 H22 O4'
_chemical_formula_weight         314.36
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 104.529(8)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   11.7563(19)
_cell_length_b                   5.3917(8)
_cell_length_c                   12.861(2)
_cell_measurement_reflns_used    1925
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      21.03
_cell_measurement_theta_min      3.27
_cell_volume                     789.1(2)
_computing_cell_refinement       'SAINT v8.34A (Bruker-AXS, 2013)'
_computing_data_collection       'APEX2 v2014.9-0 (Bruker-AXS, 2014)'
_computing_data_reduction        'SAINT v8.34A (Bruker-AXS, 2013)'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-2013/1 (Sheldrick, 2013)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 8.33
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Bruker KAPPA APEXII CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0848
_diffrn_reflns_av_unetI/netI     0.0832
_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       -12
_diffrn_reflns_limit_k_max       5
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            8970
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 1.000
_diffrn_reflns_theta_full        22.464
_diffrn_reflns_theta_max         22.464
_diffrn_reflns_theta_min         1.636
_diffrn_source                   'fine-focus sealed tube'
_exptl_absorpt_coefficient_mu    0.092
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS-2014/4 (Sheldrick, 2014)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.323
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       hollow
_exptl_crystal_F_000             336
_exptl_crystal_size_max          0.500
_exptl_crystal_size_mid          0.100
_exptl_crystal_size_min          0.050
_exptl_transmission_factor_max   0.7461
_exptl_transmission_factor_min   0.5501
_refine_diff_density_max         0.181
_refine_diff_density_min         -0.210
_refine_diff_density_rms         0.049
_refine_ls_abs_structure_details
; 
 Flack x determined using 511 quotients [(I+)-(I-)]/[(I+)+(I-)] 
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259). 
;
_refine_ls_abs_structure_Flack   0.4(10)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.016
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     213
_refine_ls_number_reflns         2037
_refine_ls_number_restraints     2
_refine_ls_restrained_S_all      1.016
_refine_ls_R_factor_all          0.0898
_refine_ls_R_factor_gt           0.0505
_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^)+(0.0594P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1037
_refine_ls_wR_factor_ref         0.1180
_reflns_Friedel_coverage         0.770
_reflns_Friedel_fraction_full    0.999
_reflns_Friedel_fraction_max     0.999
_reflns_number_gt                1451
_reflns_number_total             2037
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo7b02825_si_005.cif
_cod_data_source_block           rac01
_cod_original_cell_volume        789.2(2)
_cod_original_sg_symbol_H-M      'P 21'
_cod_database_code               4035487
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.956
_shelx_estimated_absorpt_t_max   0.995
_shelx_res_checksum              74592
_shelx_hkl_checksum              29986