Cascade Polycyclization: Exploration of a Convergent Route to Access Various Tricyclic and Tetracyclic Products Related to Sterols
Benoit Guay; Pierre Deslongchamps; Journal of Organic Chemistry 68 (2003) 6140–6148; doi:10.1021/jo034280n

data_4022432
_publ_section_title
;
 Cascade Polycyclization: Exploration of a Convergent Route
 to Access Various Tricyclic and Tetracyclic Products
 Related to Sterols
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              6140
_journal_page_last               6148
_journal_paper_doi               10.1021/jo034280n
_journal_volume                  68
_journal_year                    2003
_chemical_formula_sum            'C21 H26 O5'
_chemical_formula_weight         358.42
_space_group_IT_number           2
_symmetry_cell_setting           triclinic
_symmetry_space_group_name_Hall  '-P 1'
_symmetry_space_group_name_H-M   'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                69.967(10)
_cell_angle_beta                 83.763(6)
_cell_angle_gamma                78.833(6)
_cell_formula_units_Z            2
_cell_length_a                   7.1492(3)
_cell_length_b                   11.0375(12)
_cell_length_c                   12.7736(15)
_cell_measurement_temperature    293(2)
_cell_volume                     928.06(15)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.767
_diffrn_measured_fraction_theta_max 0.767
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0605
_diffrn_reflns_av_sigmaI/netI    0.0523
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       0
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -14
_diffrn_reflns_number            2524
_diffrn_reflns_theta_full        65.05
_diffrn_reflns_theta_max         65.05
_diffrn_reflns_theta_min         3.69
_exptl_absorpt_coefficient_mu    0.738
_exptl_crystal_density_diffrn    1.283
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             384
_refine_diff_density_max         0.184
_refine_diff_density_min         -0.153
_refine_diff_density_rms         0.038
_refine_ls_extinction_coef       0.0046(8)
_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   1.011
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     236
_refine_ls_number_reflns         2418
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.011
_refine_ls_R_factor_all          0.0891
_refine_ls_R_factor_gt           0.0526
_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^)+(0.0573P)^2^+0.3558P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1250
_refine_ls_wR_factor_ref         0.1485
_reflns_number_gt                1528
_reflns_number_total             2418
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo034280nsi20030611_112520_5.cif
_cod_data_source_block           ben1599b
_cod_database_code               4022432