Organocatalytic hetero [4+2] cycloaddition reactions of 2-(1-alkynyl)-2-alkene-1-ones: metal-free access to highly substituted 4H-pyrans.
Yu, Xiuzhao; Cao, Zhongyan; Zhang, Junliang; Organic & biomolecular chemistry 8 (2010) 5059–5061; doi:10.1039/c0ob00334d

data_7153482
_publ_section_title
;
 Organocatalytic hetero [4+2] cycloaddition reactions of
 2-(1-alkynyl)-2-alkene-1-ones: metal-free access to highly substituted
 4H-pyrans.
;
_journal_issue                   22
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              5059
_journal_page_last               5061
_journal_paper_doi               10.1039/c0ob00334d
_journal_volume                  8
_journal_year                    2010
_chemical_formula_sum            'C48 H36 O4'
_chemical_formula_weight         676.77
_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                 98.8200(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.6442(5)
_cell_length_b                   24.3720(10)
_cell_length_c                   13.0153(6)
_cell_measurement_temperature    173(2)
_cell_volume                     3650.0(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      173(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0240
_diffrn_reflns_av_sigmaI/netI    0.0254
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       28
_diffrn_reflns_limit_k_min       -28
_diffrn_reflns_limit_l_max       15
_diffrn_reflns_limit_l_min       -15
_diffrn_reflns_number            42410
_diffrn_reflns_theta_full        25.01
_diffrn_reflns_theta_max         25.01
_diffrn_reflns_theta_min         1.67
_exptl_absorpt_coefficient_mu    0.077
_exptl_absorpt_correction_T_max  1
_exptl_absorpt_correction_T_min  0.800603
_exptl_absorpt_correction_type   multi-scan
_exptl_crystal_colour            'light yellow'
_exptl_crystal_density_diffrn    1.232
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1424
_exptl_crystal_size_max          0.569
_exptl_crystal_size_mid          0.552
_exptl_crystal_size_min          0.483
_refine_diff_density_max         0.439
_refine_diff_density_min         -0.268
_refine_diff_density_rms         0.032
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.8(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.026
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     937
_refine_ls_number_reflns         12760
_refine_ls_number_restraints     7
_refine_ls_restrained_S_all      1.044
_refine_ls_R_factor_all          0.0407
_refine_ls_R_factor_gt           0.0344
_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^)+(0.0448P)^2^+0.7568P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0840
_refine_ls_wR_factor_ref         0.0891
_reflns_number_gt                11580
_reflns_number_total             12760
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c0ob00334d.txt
_cod_data_source_block           z
_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 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 1891 2012-01-12 08:04:46Z andrius 
;
_cod_original_sg_symbol_H-M      P2(1)
_cod_database_code               7153482