An Entry to Enantioenriched 3,3-Disubstituted Phthalides through Asymmetric Phase-Transfer-Catalyzed γ-Alkylation.
Sicignano, Marina; Schettini, Rosaria; Pierri, Giovanni; Marino, Maria Leda; Izzo, Irene; De Riccardis, Francesco; Bernardi, Luca; Sala, Giorgio Della; The Journal of organic chemistry  (2020) –; doi:10.1021/acs.joc.0c00880

data_4038430
_publ_section_title
;
 An Entry to Enantioenriched 3,3-Disubstituted Phthalides through
 Asymmetric Phase-Transfer-Catalyzed \g-Alkylation.
;
_journal_name_full               'The Journal of organic chemistry'
_journal_paper_doi               10.1021/acs.joc.0c00880
_journal_year                    2020
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C20 H20 O4'
_chemical_formula_sum            'C20 H20 O4'
_chemical_formula_weight         324.36
_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
_atom_sites_solution_primary     direct
_audit_creation_date             2020-01-13
_audit_creation_method
;
Olex2 1.2
(compiled 2018.05.29 svn.r3508 for OlexSys, GUI svn.r5506)
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   6.0173(2)
_cell_length_b                   16.8850(5)
_cell_length_c                   17.2658(5)
_cell_measurement_reflns_used    9915
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      71.00
_cell_measurement_theta_min      5.24
_cell_volume                     1754.24(9)
_computing_cell_refinement       'Bruker SAINT'
_computing_data_collection       'Bruker APEX2'
_computing_data_reduction        'Bruker SAINT'
_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    'ShelXS (Sheldrick, 2008)'
_diffrn_ambient_temperature      296.15
_diffrn_measured_fraction_theta_full 0.971
_diffrn_measured_fraction_theta_max 0.966
_diffrn_measurement_device_type  'Bruker APEX-II CCD'
_diffrn_measurement_method       '\f and \w scans'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0361
_diffrn_reflns_av_unetI/netI     0.0305
_diffrn_reflns_Laue_measured_fraction_full 0.971
_diffrn_reflns_Laue_measured_fraction_max 0.966
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       20
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            17420
_diffrn_reflns_point_group_measured_fraction_full 0.972
_diffrn_reflns_point_group_measured_fraction_max 0.960
_diffrn_reflns_theta_full        67.679
_diffrn_reflns_theta_max         71.270
_diffrn_reflns_theta_min         5.239
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.690
_exptl_absorpt_correction_T_max  0.7534
_exptl_absorpt_correction_T_min  0.5726
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2014/5 (Bruker,2014/5) was used for absorption correction.
wR2(int) was 0.1628 before and 0.0581 after correction.
The Ratio of minimum to maximum transmission is 0.7600.
The \l/2 correction factor is Not present.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.228
_exptl_crystal_description       prism
_exptl_crystal_F_000             688
_exptl_crystal_size_max          0.56
_exptl_crystal_size_mid          0.38
_exptl_crystal_size_min          0.27
_refine_diff_density_max         0.118
_refine_diff_density_min         -0.126
_refine_diff_density_rms         0.023
_refine_ls_abs_structure_details
;
 Flack x determined using 1271 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.07(5)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.058
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     220
_refine_ls_number_reflns         3280
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.058
_refine_ls_R_factor_all          0.0355
_refine_ls_R_factor_gt           0.0343
_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^)+(0.0485P)^2^+0.1386P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0888
_refine_ls_wR_factor_ref         0.0898
_reflns_Friedel_coverage         0.707
_reflns_Friedel_fraction_full    0.973
_reflns_Friedel_fraction_max     0.952
_reflns_number_gt                3157
_reflns_number_total             3280
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo0c00880_si_002.cif
_cod_data_source_block           mlm80_4
_cod_database_code               4038430
_shelx_shelxl_version_number     2018/3
_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
2.a Secondary CH2 refined with riding coordinates:
 C14(H14A,H14B)
2.b Aromatic/amide H refined with riding coordinates:
 C2(H2), C5(H5), C16(H16), C4(H4), C17(H17), C3(H3), C20(H20), C18(H18),
 C19(H19)
2.c Idealised Me refined as rotating group:
 C11(H11A,H11B,H11C), C12(H12A,H12B,H12C), C13(H13A,H13B,H13C)
;
_shelx_res_checksum              40315
_shelx_hkl_checksum              74201
_olex2_submission_special_instructions 'No special instructions were received'