Pallambins A and B, Unprecedented Hexacyclic 19-nor-Secolabdane Diterpenoids from the Chinese Liverwort Pallavicinia ambigua.
Wang, Li-Ning; Zhang, Jiao-Zhen; Li, Xia; Wang, Xiao-Ning; Xie, Chun-Feng; Zhou, Jin-Chuan; Lou, Hong-Xiang; Organic letters 14 (2012) 1102–1105; doi:10.1021/ol3000124

data_1503623
_publ_section_title
;
 Pallambins A and B, Unprecedented Hexacyclic 19-nor-Secolabdane
 Diterpenoids from the Chinese Liverwort Pallavicinia ambigua.
;
_journal_issue                   4
_journal_name_full               'Organic letters'
_journal_page_first              1102
_journal_page_last               1105
_journal_paper_doi               10.1021/ol3000124
_journal_volume                  14
_journal_year                    2012
_chemical_absolute_configuration unkown
_chemical_formula_moiety         'C19 H22 O4'
_chemical_formula_sum            'C19 H22 O4'
_chemical_formula_weight         314.37
_chemical_name_common            'pallambin A'
_space_group_IT_number           18
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2 2ab'
_symmetry_space_group_name_H-M   'P 21 21 2'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   13.7792(17)
_cell_length_b                   39.505(5)
_cell_length_c                   6.2897(8)
_cell_measurement_reflns_used    2473
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      19.43
_cell_measurement_theta_min      2.54
_cell_volume                     3423.8(7)
_computing_cell_refinement       'APEX2 Software Suite (Bruker,2005)'
_computing_data_collection       'APEX2 Software Suite (Bruker,2005)'
_computing_data_reduction        'APEX2 Software Suite (Bruker,2005)'
_computing_molecular_graphics    'SHELXTL (Bruker, 1997)'
_computing_publication_material  'WINGX (Farrugia,1999)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SIR97 (Altomare,1999)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Bruker APEX2 CCD area-detector diffractometer'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71069
_diffrn_reflns_av_R_equivalents  0.0530
_diffrn_reflns_av_sigmaI/netI    0.0742
_diffrn_reflns_limit_h_max       17
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       43
_diffrn_reflns_limit_k_min       -51
_diffrn_reflns_limit_l_max       8
_diffrn_reflns_limit_l_min       -8
_diffrn_reflns_number            21280
_diffrn_reflns_theta_full        27.56
_diffrn_reflns_theta_max         27.56
_diffrn_reflns_theta_min         1.03
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.085
_exptl_absorpt_correction_T_max  0.9983
_exptl_absorpt_correction_T_min  0.9710
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'APEX2 Software Suite (Bruker,2005)'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.220
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             1344
_exptl_crystal_size_max          0.35
_exptl_crystal_size_mid          0.12
_exptl_crystal_size_min          0.02
_refine_diff_density_max         1.001
_refine_diff_density_min         -0.310
_refine_diff_density_rms         0.128
_refine_ls_extinction_coef       0.0172(17)
_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   1.018
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     424
_refine_ls_number_reflns         7813
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.018
_refine_ls_R_factor_all          0.1445
_refine_ls_R_factor_gt           0.0728
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.1150P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1814
_refine_ls_wR_factor_ref         0.2212
_reflns_number_gt                3910
_reflns_number_total             7813
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol3000124_si_002.cif
_cod_data_source_block           wangln01
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Orthorhombic' changed to
'orthorhombic' according to
/home/saulius/struct/CIF-dictionaries/cif_core.dic dictionary named
'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      'P2(1)2(1)2 '
_cod_database_code               1503623