Electronic Donation or Steric Contraction: A Spectroscopic and Structural Analysis of Medium-Sized Constrained Rings for Potential Long-Range Hyperconjugation.
Lee, Robert; Bashrum, Bryan; Cagle, Ethan C.; Walters, Jillian; Massey, Jake; Zanghi, Monica; Birchfield, Carolyn; French, David; Joy, Jessica; Dos Passos Gomes, Gabriel; Wiget, Paul A.; The Journal of organic chemistry 84 (2019) 9897–9906; doi:10.1021/acs.joc.9b00979

data_4034008
_publ_section_title
;
 Electronic Donation or Steric Contraction: A Spectroscopic and Structural
 Analysis of Medium-Sized Constrained Rings for Potential Long-Range
 Hyperconjugation.
;
_journal_issue                   16
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              9897
_journal_page_last               9906
_journal_paper_doi               10.1021/acs.joc.9b00979
_journal_volume                  84
_journal_year                    2019
_chemical_formula_moiety         'C10 H12 O2'
_chemical_formula_sum            'C10 H12 O2'
_chemical_formula_weight         164.21
_chemical_name_systematic
(1R,2R,5S,6S)-11-oxatricyclo[4.3.1.12,5]undec-3-en-10-one
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_symmetry_Int_Tables_number      14
_atom_sites_solution_primary     direct
_audit_creation_date             2019-02-27
_audit_creation_method
;
Olex2 1.2
(compiled 2018.05.29 svn.r3508 for OlexSys, GUI svn.r5506)
;
_cell_angle_alpha                90
_cell_angle_beta                 100.9440(10)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   9.04980(10)
_cell_length_b                   6.42590(10)
_cell_length_c                   14.3599(2)
_cell_measurement_reflns_used    24
_cell_measurement_temperature    173(2)
_cell_measurement_theta_max      58.77
_cell_measurement_theta_min      12.61
_cell_volume                     819.89(2)
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'olex2.refine (Bourhis et al., 2015)'
_computing_structure_solution    'XS (Sheldrick, 2008)'
_diffrn_ambient_temperature      173.0
_diffrn_measured_fraction_theta_full 0.9968
_diffrn_measured_fraction_theta_max 0.9968
_diffrn_measurement_device_type  Bruker
_diffrn_measurement_method       'omega and phi scans'
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0226
_diffrn_reflns_av_unetI/netI     0.0155
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       7
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            8932
_diffrn_reflns_theta_full        70.0167
_diffrn_reflns_theta_max         70.02
_diffrn_reflns_theta_min         4.98
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.739
_exptl_absorpt_correction_T_max  0.9947
_exptl_absorpt_correction_T_min  0.8844
_exptl_absorpt_correction_type   numerical
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            yellow
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   yellowish
_exptl_crystal_density_diffrn    1.3302
_exptl_crystal_description       'rect. Prism'
_exptl_crystal_F_000             353.1488
_exptl_crystal_recrystallization_method 'Recrystallization from hot hexanes'
_exptl_crystal_size_max          0.17
_exptl_crystal_size_mid          0.16
_exptl_crystal_size_min          0.07
_refine_diff_density_max         0.2531
_refine_diff_density_min         -0.2348
_refine_diff_density_rms         0.0554
_refine_ls_d_res_high            0.8203
_refine_ls_d_res_low             8.8852
_refine_ls_goodness_of_fit_ref   1.0637
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_constraints    21
_refine_ls_number_parameters     109
_refine_ls_number_reflns         1553
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.0637
_refine_ls_R_factor_all          0.0427
_refine_ls_R_factor_gt           0.0401
_refine_ls_shift/su_max          0.0000
_refine_ls_shift/su_mean         0.0000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0605P)^2^+0.2471P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1034
_refine_ls_wR_factor_ref         0.1063
_reflns_Friedel_coverage         0.0
_reflns_limit_h_max              10
_reflns_limit_h_min              -11
_reflns_limit_k_max              7
_reflns_limit_k_min              0
_reflns_limit_l_max              17
_reflns_limit_l_min              0
_reflns_number_gt                1438
_reflns_number_total             1553
_reflns_threshold_expression     I>=2u(I)
_cod_data_source_file            jo9b00979_si_001.cif
_cod_data_source_block           Wigi_1_0m
_cod_database_code               4034008
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
2.a Ternary CH refined with riding coordinates:
 C2(H2), C3(H3), C6(H6), C7(H7)
2.b Secondary CH2 refined with riding coordinates:
 C1(H1a,H1b), C8(H8a,H8b), C9(H9a,H9b)
2.c Aromatic/amide H refined with riding coordinates:
 C4(H4), C5(H5)
;