Enantioselective Synthesis of Substituted δ-Lactones by Cooperative Oxidative N-Heterocyclic Carbene and Lewis Acid Catalysis.
Bera, Srikrishna; Daniliuc, Constantin G.; Studer, Armido; Organic letters 17 (2015) 4940–4943; doi:10.1021/acs.orglett.5b01932

data_1555171
_publ_section_title
;
 Enantioselective Synthesis of Substituted \d-Lactones by Cooperative
 Oxidative N-Heterocyclic Carbene and Lewis Acid Catalysis.
;
_journal_issue                   20
_journal_name_full               'Organic letters'
_journal_page_first              4940
_journal_page_last               4943
_journal_paper_doi               10.1021/acs.orglett.5b01932
_journal_volume                  17
_journal_year                    2015
_chemical_absolute_configuration ad
_chemical_formula_sum            'C23 H28 O7'
_chemical_formula_weight         416.45
_space_group_crystal_system      orthorhombic
_space_group_IT_number           19
_space_group_name_Hall           'P 2ac 2ab'
_space_group_name_H-M_alt        'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.5586(3)
_cell_length_b                   9.2119(3)
_cell_length_c                   27.3349(8)
_cell_measurement_reflns_used    9998
_cell_measurement_temperature    100.(2)
_cell_measurement_theta_max      68.1743
_cell_measurement_theta_min      5.0665
_cell_volume                     2155.11(12)
_computing_cell_refinement       'SAINT V8.34A (Bruker AXS Inc., 2013)'
_computing_data_collection
;
APEX2 v.2014.1-1 (Bruker AXS Inc., 2014)

;
_computing_data_reduction        'SAINT V8.34A (Bruker AXS Inc., 2013)'
_computing_molecular_graphics    'XP (Sheldrick, 2014)'
_computing_publication_material  'SHELXL-2014 (Sheldrick, 2014)'
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_computing_structure_solution    'SHELXL-2014 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100.(2)
_diffrn_detector_area_resol_mean 10.4167
_diffrn_measured_fraction_theta_full 0.957
_diffrn_measured_fraction_theta_max 0.957
_diffrn_measurement_device_type  'Bruker D8 Venture PHOTON 100 CMOS'
_diffrn_measurement_method       'omega and phi scans'
_diffrn_radiation_monochromator  'MX mirror'
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0407
_diffrn_reflns_av_unetI/netI     0.0373
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -9
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -30
_diffrn_reflns_number            13119
_diffrn_reflns_theta_full        61.16
_diffrn_reflns_theta_max         61.16
_diffrn_reflns_theta_min         5.07
_diffrn_source                   'Cu ImS'
_diffrn_source_type              'micro focus tube'
_exptl_absorpt_coefficient_mu    0.782
_exptl_absorpt_correction_T_max  0.93
_exptl_absorpt_correction_T_min  0.71
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
Bruker AXS (2014). SADABS, Version 2014/2, Bruker AXS Inc., Madison, Wisconsin,
USA.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.284
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       prism
_exptl_crystal_F_000             888
_exptl_crystal_size_max          0.258
_exptl_crystal_size_mid          0.103
_exptl_crystal_size_min          0.098
_refine_diff_density_max         0.284
_refine_diff_density_min         -0.311
_refine_ls_abs_structure_details
;
Flack x determined using 1081 quotients [(I+)-(I-)]/[(I+)+(I-)]
(Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.18(9)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.358
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     275
_refine_ls_number_reflns         3057
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.358
_refine_ls_R_factor_all          0.0631
_refine_ls_R_factor_gt           0.0618
_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^)+3.9903P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1241
_refine_ls_wR_factor_ref         0.1245
_reflns_number_gt                3004
_reflns_number_total             3057
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol5b01932_si_002.cif
_cod_data_source_block           stu8061
_cod_database_code               1555171
_shelx_res_checksum              68142
_shelx_hkl_checksum              98567