Cascade radical cyclisations leading to steroid ring constructions. Regio- and stereo-chemical studies using ester- and fluoro-alkene substituted polyene acyl radical intermediates
Boehm, Haydn M.; Handa, Sandeep; Pattenden, Gerald; Roberts, Lee; Blake, Alexander J.; Li, Wan-Sheung; Journal of the Chemical Society, Perkin Transactions 1  (2000) 3522–; doi:10.1039/b002999h

data_7213348
_publ_section_title
;
 Cascade radical cyclisations leading to steroid ring constructions.
 Regio- and stereo-chemical studies using ester- and fluoro-alkene
 substituted polyene acyl radical intermediates
;
_journal_issue                   20
_journal_name_full
'Journal of the Chemical Society, Perkin Transactions 1'
_journal_page_first              3522
_journal_paper_doi               10.1039/b002999h
_journal_year                    2000
_chemical_formula_moiety         'C21 H30 O4'
_chemical_formula_sum            'C21 H30 O4'
_chemical_formula_weight         346.45
_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                   8.567(3)
_cell_length_b                   12.272(14)
_cell_length_c                   16.895(3)
_cell_measurement_reflns_used    7583
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      25.0
_cell_measurement_theta_min      2.4
_cell_volume                     1776(2)
_computing_cell_refinement       FAST
_computing_data_collection       FAST
_computing_data_reduction        ABSURD
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      150(2)
_diffrn_measured_fraction_theta_full 0.916
_diffrn_measured_fraction_theta_max 0.916
_diffrn_measurement_device_type  'Enraf Nonius FAST TV dtector'
_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  0.158
_diffrn_reflns_av_sigmaI/netI    0.395
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -14
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            7583
_diffrn_reflns_theta_full        24.99
_diffrn_reflns_theta_max         24.99
_diffrn_reflns_theta_min         2.41
_diffrn_standards_decay_%        none
_exptl_absorpt_coefficient_mu    0.088
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.296
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             752
_exptl_crystal_size_max          0.10
_exptl_crystal_size_mid          0.10
_exptl_crystal_size_min          0.10
_refine_diff_density_max         0.13
_refine_diff_density_min         -0.13
_refine_diff_density_rms         0.03
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   'not reliably determined'
_refine_ls_extinction_coef       0.0065(10)
_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   0.406
_refine_ls_hydrogen_treatment    geom
_refine_ls_matrix_type           full
_refine_ls_number_parameters     227
_refine_ls_number_reflns         2769
_refine_ls_number_restraints     74
_refine_ls_restrained_S_all      0.401
_refine_ls_R_factor_all          0.131
_refine_ls_R_factor_gt           0.035
_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^)+(0.00P)^2^+0.00P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0582
_refine_ls_wR_factor_ref         0.0821
_reflns_number_gt                884
_reflns_number_total             2769
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            b002999hsup1.cif
_cod_data_source_block           STERAC
_cod_depositor_comments
;
The following automatic conversions were performed:
'_atom_site_symetry_multiplicity' tag replaced with
'_atom_site_symmetry_multiplicity'.

Automatic conversion script
Id: cif_correct_tags 1440 2010-10-19 06:21:57Z saulius 
;
_cod_original_sg_symbol_H-M      P2(1)2(1)2(1)
_cod_database_code               7213348