Lactols in an asymmetric aldol-desymmetrization sequence: access to tetrahydro-4H-furo[2,3-b]pyran-2-one and tetrahydro-4H-furo[2,3-b]furan-2-one derivatives.
Li, Ji-Yao; Yu, Ke-Wei; Xie, Chao-Chao; Liu, Yan-Kai; Organic & biomolecular chemistry 15 (2017) 1407–1417; doi:10.1039/c6ob02420c

data_7155431
_publ_section_title
;
 Lactols in an asymmetric aldol-desymmetrization sequence: access to
 tetrahydro-4H-furo[2,3-b]pyran-2-one and
 tetrahydro-4H-furo[2,3-b]furan-2-one derivatives.
;
_journal_issue                   6
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              1407
_journal_page_last               1417
_journal_paper_doi               10.1039/c6ob02420c
_journal_volume                  15
_journal_year                    2017
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C16 H17 Br O7'
_chemical_formula_sum            'C16 H17 Br O7'
_chemical_formula_weight         401.19
_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
_atom_sites_solution_primary     dual
_audit_creation_date             2016-08-29
_audit_creation_method
;
Olex2 1.2-beta
(compiled 2016.08.25 svn.r3337 for OlexSys, GUI svn.r5221)
;
_audit_update_record
;
2016-10-17 deposited with the CCDC.
2017-01-05 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 99.962(7)
_cell_angle_gamma                90
_cell_formula_units_Z            2
_cell_length_a                   5.5345(9)
_cell_length_b                   10.8618(18)
_cell_length_c                   14.707(2)
_cell_measurement_reflns_used    5124
_cell_measurement_temperature    293.15
_cell_measurement_theta_max      68
_cell_measurement_theta_min      3
_cell_volume                     870.8(2)
_computing_cell_refinement       'SAINT v8.37A (Bruker, 2015)'
_computing_data_reduction        'SAINT v8.37A (Bruker, 2015)'
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'ShelXL (Sheldrick, 2015)'
_computing_structure_solution    'ShelXT (Sheldrick, 2015)'
_diffrn_ambient_temperature      293.15
_diffrn_measured_fraction_theta_full 0.983
_diffrn_measured_fraction_theta_max 0.978
_diffrn_measurement_device_type  'CCD Area Detector'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0349
_diffrn_reflns_av_unetI/netI     0.0464
_diffrn_reflns_Laue_measured_fraction_full 0.983
_diffrn_reflns_Laue_measured_fraction_max 0.978
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       13
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       17
_diffrn_reflns_limit_l_min       -17
_diffrn_reflns_number            6095
_diffrn_reflns_point_group_measured_fraction_full 0.942
_diffrn_reflns_point_group_measured_fraction_max 0.937
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         68.509
_diffrn_reflns_theta_min         3.051
_exptl_absorpt_coefficient_mu    3.532
_exptl_absorpt_correction_T_max  0.7531
_exptl_absorpt_correction_T_min  0.4350
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2014/5 (Bruker,2014/5) was used for absorption correction.
wR2(int) was 0.1241 before and 0.0624 after correction.
The Ratio of minimum to maximum transmission is 0.5776.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.530
_exptl_crystal_description       block
_exptl_crystal_F_000             408
_refine_diff_density_max         0.301
_refine_diff_density_min         -0.352
_refine_diff_density_rms         0.045
_refine_ls_abs_structure_details
;
 Flack x determined using 1219 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.089(12)
_refine_ls_extinction_coef       0.043(4)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     'SHELXL-2014/7 (Sheldrick 2014'
_refine_ls_goodness_of_fit_ref   1.053
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     221
_refine_ls_number_reflns         3000
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.053
_refine_ls_R_factor_all          0.0410
_refine_ls_R_factor_gt           0.0392
_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^)+(0.0512P)^2^+0.2411P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1042
_refine_ls_wR_factor_ref         0.1058
_reflns_Friedel_coverage         0.813
_reflns_Friedel_fraction_full    0.896
_reflns_Friedel_fraction_max     0.891
_reflns_number_gt                2856
_reflns_number_total             3000
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            c6ob02420c2.cif
_cod_data_source_block           cu_2016003_0m
_cod_depositor_comments          'Adding full bibliography for 7155431.cif.'
_cod_database_code               7155431
_shelx_estimated_absorpt_t_max   68
_shelx_estimated_absorpt_t_min   3
_olex2_refinement_description
;
1. Fixed Uiso
 At 1.2 times of:
  All C(H) groups, All C(H,H) groups
 At 1.5 times of:
  All C(H,H,H) groups, All O(H) groups
2.a Ternary CH refined with riding coordinates:
 C7(H7), C8(H8), C14(H14)
2.b Secondary CH2 refined with riding coordinates:
 C12(H12A,H12B), C15(H15A,H15B)
2.c Aromatic/amide H refined with riding coordinates:
 C4(H4), C5(H5A), C16(H16)
2.d Idealised Me refined as rotating group:
 C3(H3A,H3B,H3C), C13(H13A,H13B,H13C)
2.e Idealised tetrahedral OH refined as rotating group:
 O5(H5)
;
_shelx_res_checksum              82642
_shelx_shelxl_version_number     2014/7
_olex2_submission_special_instructions 'No special instructions were received'