How an early or late transition state impacts the stereoselectivity of tetrahydropyran formation by intramolecular oxa-Michael addition.
Csókás, Dániel; Ho, Annabel Xuan Ying; Ramabhadran, Raghunath O.; Bates, Roderick W.; Organic & biomolecular chemistry 17 (2019) 6293–6304; doi:10.1039/c9ob00750d

data_7156901
_publ_section_title
;
 How an early or late transition state impacts the stereoselectivity of
 tetrahydropyran formation by intramolecular oxa-Michael addition.
;
_journal_issue                   25
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              6293
_journal_page_last               6304
_journal_paper_doi               10.1039/c9ob00750d
_journal_volume                  17
_journal_year                    2019
_chemical_formula_sum            'C19 H19 Br O2'
_chemical_formula_weight         359.25
_space_group_crystal_system      orthorhombic
_space_group_IT_number           33
_space_group_name_Hall           'P 2c -2n'
_space_group_name_H-M_alt        'P n a 21'
_symmetry_space_group_name_Hall  'P 2c -2n'
_symmetry_space_group_name_H-M   'P n a 21'
_atom_sites_solution_hydrogens   geom
_audit_update_record
;
2019-02-07 deposited with the CCDC.    2019-06-07 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   19.185(2)
_cell_length_b                   5.7454(7)
_cell_length_c                   29.323(3)
_cell_measurement_reflns_used    9924
_cell_measurement_temperature    100.(2)
_cell_measurement_theta_max      27.8080
_cell_measurement_theta_min      2.2321
_cell_volume                     3232.1(6)
_computing_cell_refinement       'SAINT V8.38A (Bruker AXS Inc., 2017)'
_computing_data_collection       'APEX3 (Bruker AXS Inc., 2017)'
_computing_data_reduction        'SAINT V8.38A (Bruker AXS Inc., 2017)'
_computing_publication_material  'APEX3 (Bruker AXS Inc., 2017)'
_computing_structure_refinement  'SHELXL-2016/6 (Sheldrick, 2016)'
_computing_structure_solution    'SHELXT 2014/5 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100.(2)
_diffrn_detector_area_resol_mean 7.4074
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type  'Photon II CPADs detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  'Multilayer Mirror'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0670
_diffrn_reflns_av_unetI/netI     0.0905
_diffrn_reflns_limit_h_max       24
_diffrn_reflns_limit_h_min       -25
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -7
_diffrn_reflns_limit_l_max       38
_diffrn_reflns_limit_l_min       -38
_diffrn_reflns_number            18414
_diffrn_reflns_theta_full        27.94
_diffrn_reflns_theta_max         27.94
_diffrn_reflns_theta_min         2.23
_diffrn_source                   'Incoatec microfocus source'
_diffrn_source_type              'Bruker D8 Quest'
_exptl_absorpt_coefficient_mu    2.548
_exptl_absorpt_correction_T_max  0.91
_exptl_absorpt_correction_T_min  0.45
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
'TWINABS - Bruker AXS scaling for twinned crystals - Version 2012/1'
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.477
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1472
_exptl_crystal_size_max          0.320
_exptl_crystal_size_mid          0.120
_exptl_crystal_size_min          0.040
_refine_diff_density_max         2.354
_refine_diff_density_min         -0.874
_refine_ls_abs_structure_details
;

Refined as an inversion twin.
;
_refine_ls_abs_structure_Flack   0.39(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.034
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     398
_refine_ls_number_reflns         7547
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.033
_refine_ls_R_factor_all          0.0960
_refine_ls_R_factor_gt           0.0645
_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^)+(0.0817P)^2^+2.4536P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1480
_refine_ls_wR_factor_ref         0.1637
_reflns_number_gt                5514
_reflns_number_total             7547
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c9ob00750d5.cif
_cod_data_source_block           rb107m
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_absorpt_correction_type' value 'Multi-Scan' changed to
'multi-scan' according to
/home/data/users/saulius/crontab/automatic-downloads/rss-feeds/RSC/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 4973 2017-02-22 13:04:09Z antanas 

 Adding full bibliography for 7156900--7156902.cif.
;
_cod_original_cell_volume        3232.1(7)
_cod_database_code               7156901
_shelx_res_checksum              92641