Maltol- and Allomaltol-Derived Oxidopyrylium Ylides: Methyl Substitution Pattern Kinetically Influences [5 + 3] Dimerization versus [5 + 2] Cycloaddition Reactions.
Bejcek, Lauren P.; Garimallaprabhakaran, Aswin K.; Suyabatmaz, Duygu M.; Greer, Alexander; Hersh, William H.; Greer, Edyta M.; Murelli, Ryan P.; The Journal of organic chemistry  (2019) –; doi:10.1021/acs.joc.9b02137

data_4033608
_publ_section_title
;
 Maltol- and Allomaltol-Derived Oxidopyrylium Ylides: Methyl Substitution
 Pattern Kinetically Influences [5 + 3] Dimerization versus [5 + 2]
 Cycloaddition Reactions.
;
_journal_name_full               'The Journal of organic chemistry'
_journal_paper_doi               10.1021/acs.joc.9b02137
_journal_year                    2019
_chemical_formula_moiety         'C14 H16 O6'
_chemical_formula_sum            'C14 H16 O6'
_chemical_formula_weight         280.27
_chemical_name_common            'Oxidopyrylium dimer 8'
_chemical_name_systematic
;
 racemic (1R,2S,6S,7R)-6,9-dimethoxy-4,7-dimethyl-3,11-
 dioxatricyclo[5.3.1.12,6]-dodeca-4,8-diene-10,12-dione
;
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 93.384(4)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.269(3)
_cell_length_b                   9.888(4)
_cell_length_c                   16.124(6)
_cell_measurement_reflns_used    6227
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      27.117
_cell_measurement_theta_min      2.418
_cell_volume                     1316.1(9)
_computing_cell_refinement       'SAINT V8.34A (Bruker AXS, 2013)'
_computing_data_collection       'Bruker Instrument Service v2011.6.0.0'
_computing_data_reduction        'SAINT V8.34A (Bruker AXS, 2013)'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Mercury 4.1.0 (Build 235322), 2019'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      100(2)
_diffrn_detector_area_resol_mean 8.3333
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.992
_diffrn_measurement_device_type  'Bruker Breeze CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0393
_diffrn_reflns_av_unetI/netI     0.0276
_diffrn_reflns_Laue_measured_fraction_full 1.000
_diffrn_reflns_Laue_measured_fraction_max 0.992
_diffrn_reflns_limit_h_max       10
_diffrn_reflns_limit_h_min       -10
_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            14939
_diffrn_reflns_point_group_measured_fraction_full 1.000
_diffrn_reflns_point_group_measured_fraction_max 0.992
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         27.236
_diffrn_reflns_theta_min         2.417
_diffrn_source                   'fine-focus tube'
_exptl_absorpt_coefficient_mu    0.111
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'SADABS-2014/5 (Bruker AXS)'
_exptl_crystal_colour            clear
_exptl_crystal_density_diffrn    1.414
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       'irregular cube'
_exptl_crystal_F_000             592
_exptl_crystal_size_max          0.403
_exptl_crystal_size_mid          0.338
_exptl_crystal_size_min          0.317
_exptl_transmission_factor_max   0.7455
_exptl_transmission_factor_min   0.6727
_refine_diff_density_max         0.375
_refine_diff_density_min         -0.227
_refine_diff_density_rms         0.046
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.048
_refine_ls_hydrogen_treatment    noref
_refine_ls_matrix_type           full
_refine_ls_number_parameters     185
_refine_ls_number_reflns         2924
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.048
_refine_ls_R_factor_all          0.0418
_refine_ls_R_factor_gt           0.0363
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0416P)^2^+0.6153P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0905
_refine_ls_wR_factor_ref         0.0945
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2545
_reflns_number_total             2924
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo9b02137_si_001.cif
_cod_data_source_block           rm1_p279_0m_a
_cod_database_code               4033608
_shelx_estimated_absorpt_t_min   0.957
_shelx_estimated_absorpt_t_max   0.966
_shelx_res_checksum              12796
_shelx_hkl_checksum              73406