Skeleton-rearranged pentacyclic diterpenoids possessing a cyclobutane ring from Euphorbia wallichii.
Pan, Li; Zhou, Ping; Zhang, Xiaofeng; Peng, Shulin; Ding, Lisheng; Qiu, Samuel X.; Organic letters 8 (2006) 2775–2778; doi:10.1021/ol0608552

data_1506019
_publ_section_title
;
 Skeleton-rearranged pentacyclic diterpenoids possessing a cyclobutane
 ring from Euphorbia wallichii.
;
_journal_issue                   13
_journal_name_full               'Organic letters'
_journal_page_first              2775
_journal_page_last               2778
_journal_paper_doi               10.1021/ol0608552
_journal_volume                  8
_journal_year                    2006
_chemical_formula_sum            'C20 H28 O3'
_chemical_formula_weight         316.42
_chemical_name_systematic
; 
 ? 
;
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                   9.697(2)
_cell_length_b                   11.333(3)
_cell_length_c                   31.449(9)
_cell_measurement_reflns_used    33
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      14.52
_cell_measurement_theta_min      3.70
_cell_volume                     3456.1(15)
_computing_cell_refinement       'Siemens XSCANS'
_computing_data_collection       'Siemens XSCANS'
_computing_data_reduction        'Siemens SHELXTL'
_computing_molecular_graphics    'Siemens SHELXTL'
_computing_publication_material  'Siemens SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 1.000
_diffrn_measurement_device_type  'Siemens P4'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'normal-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0132
_diffrn_reflns_av_sigmaI/netI    0.0716
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       0
_diffrn_reflns_limit_k_max       14
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       40
_diffrn_reflns_limit_l_min       -1
_diffrn_reflns_number            4587
_diffrn_reflns_theta_full        27.00
_diffrn_reflns_theta_max         27.00
_diffrn_reflns_theta_min         1.29
_diffrn_standards_decay_%        1.41
_diffrn_standards_interval_count 97
_diffrn_standards_number         3
_exptl_absorpt_coefficient_mu    0.080
_exptl_absorpt_correction_type   none
_exptl_crystal_density_diffrn    1.216
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             1376
_exptl_crystal_size_max          0.58
_exptl_crystal_size_mid          0.44
_exptl_crystal_size_min          0.36
_refine_diff_density_max         0.270
_refine_diff_density_min         -0.161
_refine_diff_density_rms         0.036
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0(10)
_refine_ls_extinction_coef       0.0027(4)
_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   0.901
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     450
_refine_ls_number_reflns         4260
_refine_ls_number_restraints     6
_refine_ls_restrained_S_all      0.901
_refine_ls_R_factor_all          0.0983
_refine_ls_R_factor_gt           0.0498
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0495P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0981
_refine_ls_wR_factor_ref         0.1099
_reflns_number_gt                2334
_reflns_number_total             4260
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol0608552si20060410_022703.cif
_cod_data_source_block           y2050
_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_cell_volume        3456.2(14)
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               1506019