Non-catalytic approach to the synthesis of partially reduced 'S' shaped dioxathia- and oxadithiahelicenes through base induced inter- and intramolecular C-C bond formation.
Maurya, Hardesh K.; Tandon, Vishnu K.; Kumar, Brijesh; Kumar, Abhinav; Huch, Volker; Ram, Vishnu Ji; Organic & biomolecular chemistry 10 (2012) 605–613; doi:10.1039/c1ob06091k

data_7152105
_publ_section_title
;
 Non-catalytic approach to the synthesis of partially reduced 'S' shaped
 dioxathia- and oxadithiahelicenes through base induced inter- and
 intramolecular C-C bond formation.
;
_journal_issue                   3
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              605
_journal_page_last               613
_journal_paper_doi               10.1039/c1ob06091k
_journal_volume                  10
_journal_year                    2012
_chemical_formula_sum            'C17 H13 Cl N2 O2 S'
_chemical_formula_weight         344.80
_space_group_IT_number           29
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2c -2ac'
_symmetry_space_group_name_H-M   'P c a 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            8
_cell_length_a                   8.7105(6)
_cell_length_b                   8.3893(6)
_cell_length_c                   41.097(3)
_cell_measurement_reflns_used    9226
_cell_measurement_temperature    132(2)
_cell_measurement_theta_max      30.73
_cell_measurement_theta_min      2.62
_cell_volume                     3003.2(4)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      132(2)
_diffrn_measured_fraction_theta_full 0.988
_diffrn_measured_fraction_theta_max 0.988
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w 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  0.1281
_diffrn_reflns_av_sigmaI/netI    0.0827
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       60
_diffrn_reflns_limit_l_min       -58
_diffrn_reflns_number            54973
_diffrn_reflns_theta_full        31.28
_diffrn_reflns_theta_max         31.28
_diffrn_reflns_theta_min         0.99
_exptl_absorpt_coefficient_mu    0.404
_exptl_absorpt_correction_T_max  0.9501
_exptl_absorpt_correction_T_min  0.7051
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_density_diffrn    1.525
_exptl_crystal_density_meas      0
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             1424
_exptl_crystal_size_max          0.93
_exptl_crystal_size_mid          0.44
_exptl_crystal_size_min          0.13
_refine_diff_density_max         0.425
_refine_diff_density_min         -0.372
_refine_diff_density_rms         0.083
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.48(6)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.038
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     415
_refine_ls_number_reflns         9542
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.038
_refine_ls_R_factor_all          0.0746
_refine_ls_R_factor_gt           0.0562
_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^)+(0.0792P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1334
_refine_ls_wR_factor_ref         0.1430
_reflns_number_gt                7801
_reflns_number_total             9542
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c1ob06091k.txt
_cod_data_source_block           sh2996
_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_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      Pca2(1)
_cod_database_code               7152105