Enantioselective synthesis of A key A-ring intermediate for the preparation of 1α,25-dihydroxyvitamin D(3).
Chen, Yan; Ju, Tong; Organic letters 13 (2011) 86–89; doi:10.1021/ol102586w

data_1501869
_publ_section_title
;
 Enantioselective synthesis of A key A-ring intermediate for the
 preparation of 1\a,25-dihydroxyvitamin D(3).
;
_journal_issue                   1
_journal_name_full               'Organic letters'
_journal_page_first              86
_journal_page_last               89
_journal_paper_doi               10.1021/ol102586w
_journal_volume                  13
_journal_year                    2011
_chemical_absolute_configuration rm
_chemical_formula_moiety         'C16 H17 N O7'
_chemical_formula_sum            'C16 H17 N O7'
_chemical_formula_weight         335.31
_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                 102.13(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            2
_cell_length_a                   7.4253(15)
_cell_length_b                   6.7697(14)
_cell_length_c                   16.333(3)
_cell_measurement_reflns_used    2895
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.89
_cell_measurement_theta_min      2.35
_cell_volume                     802.7(3)
_computing_cell_refinement       'SAINT (Bruker, 2004)'
_computing_data_collection       'APEX-II (Bruker, 2004)'
_computing_data_reduction        SAINT
_computing_molecular_graphics    'SHELXTL-XP (Bruker, 2004)'
_computing_publication_material  SHELXTL
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.990
_diffrn_measured_fraction_theta_max 0.990
_diffrn_measurement_device_type  'Bruker APEX-II area-detector diffractometer'
_diffrn_measurement_method       '\f and \w scan'
_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  0.0218
_diffrn_reflns_av_sigmaI/netI    0.0310
_diffrn_reflns_limit_h_max       8
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            4135
_diffrn_reflns_theta_full        25.20
_diffrn_reflns_theta_max         25.20
_diffrn_reflns_theta_min         2.55
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.110
_exptl_absorpt_correction_T_max  0.989
_exptl_absorpt_correction_T_min  0.975
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS (Sheldrick, 1996)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.387
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             352
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.21
_refine_diff_density_max         0.114
_refine_diff_density_min         -0.130
_refine_diff_density_rms         0.029
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.3(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.040
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     219
_refine_ls_number_reflns         2299
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.040
_refine_ls_R_factor_all          0.0496
_refine_ls_R_factor_gt           0.0371
_refine_ls_shift/su_max          0.017
_refine_ls_shift/su_mean         0.001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0519P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0875
_refine_ls_wR_factor_ref         0.0955
_reflns_number_gt                1864
_reflns_number_total             2299
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol102586w_si_002.cif
_cod_data_source_block           1
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
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_sg_symbol_H-M      'P 21'
_cod_database_code               1501869