Racemic hemiacetals as oxygen-centered pronucleophiles triggering cascade 1,4-addition/Michael reaction through dynamic kinetic resolution under iminium catalysis. Development and mechanistic insights.
Orue, Ane; Uria, Uxue; Roca-López, David; Delso, Ignacio; Reyes, Efraím; Carrillo, Luisa; Merino, Pedro; Vicario, Jose L.; Chemical science 8 (2017) 2904–2913; doi:10.1039/c7sc00009j

data_1545177
_publ_section_title
;
 Racemic hemiacetals as oxygen-centered pronucleophiles triggering cascade
 1,4-addition/Michael reaction through dynamic kinetic resolution under
 iminium catalysis. Development and mechanistic insights.
;
_journal_issue                   4
_journal_name_full               'Chemical science'
_journal_page_first              2904
_journal_page_last               2913
_journal_paper_doi               10.1039/c7sc00009j
_journal_volume                  8
_journal_year                    2017
_chemical_absolute_configuration 2S,3S,3aS,7aR
_chemical_compound_source        'synthesis as described'
_chemical_formula_moiety         'C18 H22 O6'
_chemical_formula_sum            'C18 H22 O6'
_chemical_formula_weight         334.37
_chemical_name_systematic
(2S,3S,3aS,7aR)-3-(1,3-dioxolan-2-yl)-2-phenyltetrahydro-4H,6H-spiro[furo[2,3-b]pyran-5,2'-[1,3]dioxolane]
_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'
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_audit_creation_date             2016-07-26T17:03:33-00:00
_audit_creation_method           'WinGX routine CIF_UPDATE'
_audit_update_record
;
2017-01-02 deposited with the CCDC.
2017-01-30 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 90
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   8.96150(9)
_cell_length_b                   10.02283(10)
_cell_length_c                   17.71277(19)
_cell_measurement_reflns_used    19155
_cell_measurement_temperature    100.01(10)
_cell_measurement_theta_max      76.309
_cell_measurement_theta_min      4.975
_cell_volume                     1590.95(3)
_computing_cell_refinement
;
        CrysAlisPro, Agilent Technologies,
        Version 1.171.36.24 (release 03-12-2012 CrysAlis171 .NET)
        (compiled Dec  3 2012,18:21:49)
;
_computing_data_collection
;
        CrysAlisPro, Agilent Technologies,
        Version 1.171.36.24 (release 03-12-2012 CrysAlis171 .NET)
        (compiled Dec  3 2012,18:21:49)
;
_computing_data_reduction
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        CrysAlisPro, Agilent Technologies,
        Version 1.171.36.24 (release 03-12-2012 CrysAlis171 .NET)
        (compiled Dec  3 2012,18:21:49)
;
_computing_molecular_graphics    'Olex2 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 (Dolomanov et al., 2009)'
_computing_structure_refinement  'olex2.refine (Bourhis et al., 2015)'
_computing_structure_solution    'ShelXS (Sheldrick, 2008)'
_diffrn_ambient_temperature      100.15
_diffrn_detector_area_resol_mean 5.2012
_diffrn_measured_fraction_theta_full 0.9994
_diffrn_measured_fraction_theta_max 0.9994
_diffrn_measurement_details
;
  1 omega  -67.00   -6.00   1.0000    1.0000
omega____ theta____ kappa____ phi______ frames
    -      -40.8256  125.0000 -180.0000 61

  2 omega  -64.00   28.00   1.0000    1.0000
omega____ theta____ kappa____ phi______ frames
    -      -40.8256   57.0000  150.0000 92

  3 omega  -42.00   -6.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      -83.0000   30.0000  -30.0000 36

  4 omega  -67.00  -23.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      -83.0000   30.0000   30.0000 44

  5 omega   44.00  109.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -94.0000  -90.0000 65

  6 omega   36.00   68.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -30.0000  -30.0000 32

  7 omega  101.00  146.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000   61.0000  -30.0000 45

  8 omega   35.00   61.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -30.0000    0.0000 26

  9 omega   38.00   69.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -30.0000  -60.0000 31

 10 omega   43.00   68.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -45.0000  150.0000 25

 11 omega  101.00  149.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000   45.0000  -90.0000 48

 12 omega   86.00  122.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000   61.0000    0.0000 36

 13 omega   37.00   62.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -30.0000  120.0000 25

 14 omega   58.00  145.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -77.0000   30.0000 87

 15 omega -110.00  -11.00   1.0000    1.0000
omega____ theta____ kappa____ phi______ frames
    -      -40.8256  -57.0000    0.0000 99

 16 omega -146.00  -95.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      -83.0000  178.0000  120.0000 51

 17 omega  -51.00   -9.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      -83.0000   30.0000  -60.0000 42

 18 omega   42.00   68.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -30.0000   90.0000 26

 19 omega   87.00  156.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000   45.0000  120.0000 69

 20 omega   51.00   78.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000 -111.0000   60.0000 27

 21 omega   47.00  108.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -94.0000  -30.0000 61

 22 omega   37.00   64.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -30.0000  -90.0000 27

 23 omega   58.00   98.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -94.0000 -150.0000 40

 24 omega  111.00  155.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000   45.0000 -150.0000 44

 25 omega   39.00   65.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -30.0000 -120.0000 26

 26 omega   69.00  110.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000 -111.0000 -180.0000 41

 27 omega   43.00   77.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -45.0000 -180.0000 34

 28 omega   83.00  116.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000 -111.0000   60.0000 33

 29 omega   59.00   85.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000 -111.0000  -60.0000 26

 30 omega   91.00  116.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000 -111.0000  -60.0000 25

 31 omega  112.00  138.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000   45.0000 -180.0000 26

 32 omega   96.00  150.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  111.0000 -150.0000 54

 33 omega -115.00  -11.00   1.0000    1.0000
omega____ theta____ kappa____ phi______ frames
    -      -40.8256  -57.0000   90.0000 104

 34 omega -115.00  -11.00   1.0000    1.0000
omega____ theta____ kappa____ phi______ frames
    -      -40.8256  -57.0000  -90.0000 104

 35 omega -115.00  -11.00   1.0000    1.0000
omega____ theta____ kappa____ phi______ frames
    -      -40.8256  -57.0000 -180.0000 104

 36 omega    2.00   98.00   1.0000    1.0000
omega____ theta____ kappa____ phi______ frames
    -       40.8256 -125.0000   60.0000 96

 37 omega -162.00  -49.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      -83.0000  -77.0000  150.0000 113

 38 omega -162.00  -49.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      -83.0000  -77.0000  -30.0000 113

 39 omega -162.00  -49.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      -83.0000  -77.0000   90.0000 113

 40 omega -162.00  -49.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      -83.0000  -77.0000  -90.0000 113

 41 omega -162.00  -49.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      -83.0000  -77.0000   30.0000 113

 42 omega -162.00  -49.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      -83.0000  -77.0000 -150.0000 113

 43 omega   83.00  158.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000   61.0000  150.0000 75

 44 omega   83.00  158.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000   61.0000  -60.0000 75

 45 omega   35.00   69.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -30.0000 -120.0000 34

 46 omega   29.00  109.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -94.0000 -180.0000 80

 47 omega   35.00   69.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -30.0000   60.0000 34

 48 omega   82.00  158.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000   30.0000   60.0000 76

 49 omega   35.00   69.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -30.0000  150.0000 34

 50 omega   38.00   77.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -45.0000  -60.0000 39

 51 omega   35.00   69.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -30.0000   30.0000 34

 52 omega   79.00  158.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000   77.0000   60.0000 79

 53 omega   35.00   69.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -30.0000 -150.0000 34

 54 omega   29.00   74.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000  -94.0000  -30.0000 45

 55 omega   82.00  158.00   1.0000    4.0000
omega____ theta____ kappa____ phi______ frames
    -      113.0000   30.0000 -120.0000 76

;
_diffrn_measurement_device_type  'SuperNova, Single source at offset), Atlas'
_diffrn_measurement_method       '\w scans'
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_diffrn_orient_matrix_UB_13      0.0778268
_diffrn_orient_matrix_UB_21      -0.1427712
_diffrn_orient_matrix_UB_22      0.0845443
_diffrn_orient_matrix_UB_23      -0.0075441
_diffrn_orient_matrix_UB_31      -0.0797732
_diffrn_orient_matrix_UB_32      -0.1182652
_diffrn_orient_matrix_UB_33      -0.0381326
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0406
_diffrn_reflns_av_unetI/netI     0.053
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       12
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_diffrn_reflns_number            31492
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_exptl_absorpt_coefficient_mu    0.869
_exptl_absorpt_correction_T_max  0.962
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_exptl_absorpt_correction_type   analytical
_exptl_absorpt_process_details
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        CrysAlisPro, Agilent Technologies,
        Version 1.171.36.24 (release 03-12-2012 CrysAlis171 .NET)
        (compiled Dec  3 2012,18:21:49)
Analytical numeric absorption correction using a multifaceted crystal
                        model based on expressions derived by R.C. Clark & J.S.
        (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.3959
_exptl_crystal_description       needle
_exptl_crystal_F_000             714.5655
_exptl_crystal_size_max          0.2389
_exptl_crystal_size_mid          0.1392
_exptl_crystal_size_min          0.053
_refine_diff_density_max         0.157
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_refine_diff_density_rms         0.0345
_refine_ls_abs_structure_details
'Flack, H. D. (1983). Acta Cryst. A39, 876-881.'
_refine_ls_abs_structure_Flack   0.06(11)
_refine_ls_goodness_of_fit_ref   1.0626
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_constraints    38
_refine_ls_number_parameters     216
_refine_ls_number_reflns         3160
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.0626
_refine_ls_R_factor_all          0.0255
_refine_ls_R_factor_gt           0.0246
_refine_ls_shift/su_max          0.0002
_refine_ls_shift/su_mean         0.0001
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0358P)^2^+0.2451P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0631
_refine_ls_wR_factor_ref         0.0638
_reflns_number_gt                3078
_reflns_number_total             3160
_reflns_threshold_expression     I>=2u(I)
_cod_data_source_file            c7sc00009j2.cif
_cod_data_source_block           a20150171_diacetal2
_cod_depositor_comments
;Adding full bibliography for 1545175--1545177.cif.

 Adding full bibliography for 1545175--1545177.cif.
;
_cod_original_sg_symbol_Hall     ' P 2ac 2ab'
_cod_database_code               1545177