Bio-inspired polyene cyclization: synthesis of tetracyclic terpenoids promoted by steroidal acetal-SnCl4.
Zhao, Yu-Jun; Loh, Teck-Peng; Chemical communications (Cambridge, England)  (2008) 1434–1436; doi:10.1039/b714474a

data_7102970
_publ_section_title
;
 Bio-inspired polyene cyclization: synthesis of tetracyclic terpenoids
 promoted by steroidal acetal-SnCl4.
;
_journal_issue                   12
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              1434
_journal_page_last               1436
_journal_paper_doi               10.1039/b714474a
_journal_year                    2008
_chemical_formula_sum            'C49 H72 O3'
_chemical_formula_weight         709.07
_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            4
_cell_length_a                   11.7545(3)
_cell_length_b                   14.9209(4)
_cell_length_c                   23.9958(6)
_cell_measurement_reflns_used    6357
_cell_measurement_temperature    298(2)
_cell_measurement_theta_max      0.00
_cell_measurement_theta_min      0.00
_cell_volume                     4208.57(19)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      298(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0549
_diffrn_reflns_av_sigmaI/netI    0.0365
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       21
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       34
_diffrn_reflns_limit_l_min       -34
_diffrn_reflns_number            86435
_diffrn_reflns_theta_full        30.72
_diffrn_reflns_theta_max         30.72
_diffrn_reflns_theta_min         2.18
_exptl_absorpt_coefficient_mu    0.067
_exptl_absorpt_correction_T_max  0.9900
_exptl_absorpt_correction_T_min  0.9802
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.119
_exptl_crystal_density_meas      0
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       fragment
_exptl_crystal_F_000             1560
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.15
_refine_diff_density_max         0.246
_refine_diff_density_min         -0.147
_refine_diff_density_rms         0.030
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.2(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.002
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     478
_refine_ls_number_reflns         12994
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.002
_refine_ls_R_factor_all          0.0973
_refine_ls_R_factor_gt           0.0499
_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^)+(0.0679P)^2^+0.3343P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1195
_refine_ls_wR_factor_ref         0.1438
_reflns_number_gt                7988
_reflns_number_total             12994
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b714474a.txt
_cod_data_source_block           ltp21r
_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_enum 1527 2010-12-29 10:47:43Z saulius 
;
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               7102970