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_7156902
_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_absolute_configuration ad
_chemical_formula_sum            'C19 H19 Br O2'
_chemical_formula_weight         359.25
_space_group_crystal_system      monoclinic
_space_group_IT_number           4
_space_group_name_Hall           'P 2yb'
_space_group_name_H-M_alt        'P 1 21 1'
_symmetry_space_group_name_Hall  'P 2yb'
_symmetry_space_group_name_H-M   'P 1 21 1'
_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                 97.704(3)
_cell_angle_gamma                90
_cell_formula_units_Z            6
_cell_length_a                   9.6819(10)
_cell_length_b                   9.8937(10)
_cell_length_c                   25.250(3)
_cell_measurement_reflns_used    5501
_cell_measurement_temperature    100.(2)
_cell_measurement_theta_max      25.1479
_cell_measurement_theta_min      2.3732
_cell_volume                     2396.9(4)
_computing_cell_refinement       'SAINT V8.37A (Bruker AXS Inc., 2015)'
_computing_data_collection       'APEX3 (Bruker AXS Inc., 2016)'
_computing_data_reduction        'SAINT V8.37A (Bruker AXS Inc., 2015)'
_computing_molecular_graphics    'XP (Bruker AXS Inc., 2016)'
_computing_publication_material  'APEX3 (Bruker AXS Inc., 2016)'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'XT, VERSION 2014/5'
_diffrn_ambient_temperature      100.(2)
_diffrn_detector_area_resol_mean 7.4074
_diffrn_measured_fraction_theta_full 0.997
_diffrn_measured_fraction_theta_max 0.997
_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  0.1292
_diffrn_reflns_av_unetI/netI     0.1390
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       31
_diffrn_reflns_limit_l_min       -32
_diffrn_reflns_number            32466
_diffrn_reflns_theta_full        27.14
_diffrn_reflns_theta_max         27.14
_diffrn_reflns_theta_min         2.37
_diffrn_source                   'Incoatec microfocus source'
_diffrn_source_type              'Bruker D8 Quest'
_exptl_absorpt_coefficient_mu    2.577
_exptl_absorpt_correction_T_max  0.90
_exptl_absorpt_correction_T_min  0.65
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2016/2 - Bruker AXS area detector scaling and absorption correction
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.493
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       plate
_exptl_crystal_F_000             1104
_exptl_crystal_size_max          0.240
_exptl_crystal_size_mid          0.220
_exptl_crystal_size_min          0.040
_refine_diff_density_max         0.546
_refine_diff_density_min         -1.380
_refine_ls_abs_structure_details
;

Flack x determined using 2320 quotients [(I+)-(I-)]/[(I+)+(I-)]
(Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.093(11)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.021
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     595
_refine_ls_number_reflns         10573
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.020
_refine_ls_R_factor_all          0.1161
_refine_ls_R_factor_gt           0.0635
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0450P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1258
_refine_ls_wR_factor_ref         0.1496
_reflns_number_gt                7111
_reflns_number_total             10573
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c9ob00750d5.cif
_cod_data_source_block           rb101m
_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_database_code               7156902
_shelx_res_checksum              27998