Highly sterically hindered olefins: a case of E- and Z-di-tert-butyl alpha,beta-unsaturated acids.
Ionkin, Alex S.; Marshall, William J.; Fish, Brian M.; Organic letters 10 (2008) 2303–2305; doi:10.1021/ol800808g

data_1504705
_publ_section_title
;
 Highly sterically hindered olefins: a case of E- and Z-di-tert-butyl
 alpha,beta-unsaturated acids.
;
_journal_issue                   11
_journal_name_full               'Organic letters'
_journal_page_first              2303
_journal_page_last               2305
_journal_paper_doi               10.1021/ol800808g
_journal_volume                  10
_journal_year                    2008
_chemical_formula_sum            'C11 H20 O2'
_chemical_formula_weight         184.27
_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                   6.752(3)
_cell_length_b                   10.198(5)
_cell_length_c                   17.425(9)
_cell_measurement_temperature    293(2)
_cell_volume                     1199.8(10)
_computing_cell_refinement       'Bruker XSCANS'
_computing_data_collection       'Bruker XSCANS'
_computing_data_reduction        'Bruker SHELXTL'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker 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 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'Bruker P4'
_diffrn_measurement_method       '\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  0.0615
_diffrn_reflns_av_sigmaI/netI    0.0476
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -8
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       20
_diffrn_reflns_limit_l_min       -20
_diffrn_reflns_number            8658
_diffrn_reflns_theta_full        25.03
_diffrn_reflns_theta_max         25.03
_diffrn_reflns_theta_min         2.31
_exptl_absorpt_coefficient_mu    0.068
_exptl_absorpt_correction_type   none
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.020
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             408
_exptl_crystal_size_max          0.250
_exptl_crystal_size_mid          0.070
_exptl_crystal_size_min          0.050
_refine_diff_density_max         0.265
_refine_diff_density_min         -0.203
_refine_diff_density_rms         0.048
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   2(4)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.046
_refine_ls_hydrogen_treatment    riding
_refine_ls_matrix_type           full
_refine_ls_number_parameters     135
_refine_ls_number_reflns         2096
_refine_ls_number_restraints     6
_refine_ls_restrained_S_all      1.045
_refine_ls_R_factor_all          0.1020
_refine_ls_R_factor_gt           0.0757
_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^)+(0.1326P)^2^+0.2484P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.2035
_refine_ls_wR_factor_ref         0.2287
_reflns_number_gt                1458
_reflns_number_total             2096
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol800808g-file001.cif
_cod_data_source_block           06273
_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      P2(1)2(1)2(1)
_cod_database_code               1504705