Stereodivergent approach to the asymmetric synthesis of bacillariolides: a formal synthesis of ent-bacillariolide II.
Ghosh, Subrata; Sinha, Saikat; Drew, Michael G. B.; Organic letters 8 (2006) 3781–3784; doi:10.1021/ol061377y

data_1506134
_publ_section_title
;
 Stereodivergent approach to the asymmetric synthesis of bacillariolides:
 a formal synthesis of ent-bacillariolide II.
;
_journal_issue                   17
_journal_name_full               'Organic letters'
_journal_page_first              3781
_journal_page_last               3784
_journal_paper_doi               10.1021/ol061377y
_journal_volume                  8
_journal_year                    2006
_chemical_formula_sum            'C14 H26 O4 Si'
_chemical_formula_weight         286.44
_space_group_IT_number           4
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_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                 97.796(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   7.577(8)
_cell_length_b                   8.208(11)
_cell_length_c                   13.461(15)
_cell_measurement_temperature    293(2)
_cell_volume                     829.4(17)
_computing_cell_refinement       XDS
_computing_data_collection       'XDS (Kabsch, 1988)'
_computing_data_reduction        XDS
_computing_molecular_graphics    PLATON(Spek,2004)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1997)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.984
_diffrn_measured_fraction_theta_max 0.984
_diffrn_measurement_device       'Marresearch Image Plate'
_diffrn_measurement_method
'95 frames at 2^o intervals, counting time 2 min.'
_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  0.0450
_diffrn_reflns_av_sigmaI/netI    0.0686
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       16
_diffrn_reflns_limit_l_min       -16
_diffrn_reflns_number            4877
_diffrn_reflns_theta_full        25.74
_diffrn_reflns_theta_max         25.74
_diffrn_reflns_theta_min         2.71
_exptl_absorpt_coefficient_mu    0.149
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            white
_exptl_crystal_density_diffrn    1.147
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             312
_exptl_crystal_size_max          0.25
_exptl_crystal_size_mid          0.04
_exptl_crystal_size_min          0.04
_refine_diff_density_max         0.195
_refine_diff_density_min         -0.160
_refine_diff_density_rms         0.040
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.2(2)
_refine_ls_extinction_coef       0.014(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   1.049
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     179
_refine_ls_number_reflns         2680
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.048
_refine_ls_R_factor_all          0.0723
_refine_ls_R_factor_gt           0.0553
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
;
  w=1/[\s^2^(Fo^2^)+(0.0502P)^2^+0.1379P] where P=(Fo^2^+2Fc^2^)/3 
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1129
_refine_ls_wR_factor_ref         0.1200
_reflns_number_gt                2195
_reflns_number_total             2680
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol061377ysi20060606_014428.cif
_cod_data_source_block           1
_cod_original_sg_symbol_H-M      P21
_cod_database_code               1506134