Photochemical cyclization of α-amino esters to access 3-azetidinones.
Hwang, Meemie U.; Gogoi, Achyut; Scurria, Matthew; Gutierrez, Osvaldo; Scheidt, Karl A.; Chemical science 17 (2026) 6766–6772; doi:10.1039/d5sc09994c

data_1576449
_publ_section_title
;
 Photochemical cyclization of &#x3b1;-amino esters to access
 3-azetidinones.
;
_journal_issue                   13
_journal_name_full               'Chemical science'
_journal_page_first              6766
_journal_page_last               6772
_journal_paper_doi               10.1039/d5sc09994c
_journal_volume                  17
_journal_year                    2026
_chemical_formula_moiety         'C21 H24 N3 O3 S, C F3 O3 S, 0.5(Cl2 H2 C1)'
_chemical_formula_sum            'C22.5 H25 Cl F3 N3 O6 S2'
_chemical_formula_weight         590.02
_space_group_crystal_system      monoclinic
_space_group_IT_number           15
_space_group_name_Hall           '-C 2yc'
_space_group_name_H-M_alt        'C 1 2/c 1'
_atom_sites_solution_hydrogens   mixed
_atom_sites_solution_primary     dual
_audit_block_doi                 10.5517/ccdc.csd.cc2np1v8
_audit_creation_date             2024-01-24
_audit_creation_method
;
Olex2 1.5
(compiled 2023.08.24 svn.re1ec1418 for OlexSys, GUI svn.r6817)
;
_audit_update_record
;
2025-06-09 deposited with the CCDC.	2026-02-03 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 97.585(2)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   25.0211(6)
_cell_length_b                   8.3937(3)
_cell_length_c                   25.1936(6)
_cell_measurement_reflns_used    27664
_cell_measurement_temperature    100.3(6)
_cell_measurement_theta_max      75.2150
_cell_measurement_theta_min      3.4840
_cell_volume                     5244.9(3)
_computing_cell_refinement       'CrysAlisPro 1.171.43.101a (Rigaku OD, 2023)'
_computing_data_collection
'CrysAlisPro system (CCD 43.101a 64-bit (release 13-12-2023))'
_computing_data_reduction        'CrysAlisPro 1.171.43.101a (Rigaku OD, 2023)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2019/2 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT  (Sheldrick, 2015)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      100.3(6)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            HyPix
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.982
_diffrn_measurement_details
;
List of Runs (angles in degrees, time in seconds):

  # Type    Start    End  Width  t~exp~   \w     \q     \k     \f   Frames
  1  \w    -99.00 -69.00   0.50    0.10    --  -48.85 -10.00-114.00   60
  2  \w    -27.00   0.00   0.50    0.10    --  -48.85  10.00  58.00   54
  3  \w    -11.00  14.00   0.50    0.10    --   48.85 -10.00-114.00   50
  4  \w     57.00  82.00   0.50    0.10    --   48.85  10.00  58.00   50
  5  \w    126.00 151.00   0.50    0.70    --  101.75  10.00  58.00   50
  6  \w   -148.00-107.00   0.50    0.70    -- -103.00 -10.00-114.00   82
  7  \w   -107.00 -42.00   0.50    0.10    --  -48.85 -37.00-180.00  130
  8  \w    -29.00  25.00   0.50    0.10    --  -48.85  19.00-180.00  108
  9  \w     36.00  63.00   0.50    0.10    --   48.85  57.00 120.00   54
 10  \w     92.00 120.00   0.50    0.10    --   48.85  77.00-180.00   56
 11  \w     29.00  59.00   0.50    0.10    --   48.85  77.00  90.00   60
 12  \w     28.00  54.00   0.50    0.10    --   48.85  77.00 150.00   52
 13  \w     36.00  65.00   0.50    0.10    --   48.85  57.00 150.00   58
 14  \w     40.00  65.00   0.50    0.10    --   48.85  57.00-180.00   50
 15  \w     42.00  80.00   0.50    0.10    --   48.85  37.00 120.00   76
 16  \w     79.00 120.00   0.50    0.10    --   48.85  19.00-180.00   82
 17  \w     39.00  76.00   0.50    0.10    --   48.85  57.00-120.00   74
 18  \w     29.00  74.00   0.50    0.10    --   48.85  77.00-150.00   90
 19  \w     45.00  74.00   0.50    0.10    --   48.85  19.00-180.00   58
 20  \w     28.00  63.00   0.50    0.10    --   48.85  77.00-180.00   70
 21  \w     32.00  59.00   0.50    0.10    --   48.85  77.00-120.00   54
 22  \w     41.00  83.00   0.50    0.10    --   48.85  37.00-180.00   84
 23  \w     20.00  91.00   0.50    0.10    --   48.85-125.00  60.00  142
 24  \w     28.00  54.00   0.50    0.10    --   48.85  77.00 120.00   52
 25  \w     90.00 173.00   0.50    0.70    --  101.75  61.00 150.00  166
 26  \w    138.00 163.00   0.50    0.70    --  101.75  77.00-180.00   50
 27  \w     88.00 118.00   0.50    0.70    --  101.75  61.00 120.00   60
 28  \w     33.00  65.00   0.50    0.70    --  101.75 -77.00  60.00   64
 29  \w    135.00 173.00   0.50    0.70    --  101.75  77.00  60.00   76
 30  \w     81.00 107.00   0.50    0.70    --  101.75  77.00-180.00   52
 31  \w     88.00 114.00   0.50    0.70    --  101.75  61.00  90.00   52
 32  \w     89.00 116.00   0.50    0.70    --  101.75  61.00-150.00   54
 33  \w     89.00 118.00   0.50    0.70    --  101.75  61.00-180.00   58
 34  \w     31.00 104.00   0.50    0.70    --  101.75 -94.00   0.00  146
 35  \w     74.00 102.00   0.50    0.70    --  101.75 -77.00  60.00   56
 36  \w     32.00  73.00   0.50    0.70    --  101.75 -61.00  60.00   82
 37  \w     35.00  67.00   0.50    0.70    --  101.75 -77.00-180.00   64
 38  \w     79.00 106.00   0.50    0.70    --  101.75 -94.00-150.00   54
 39  \w     93.00 173.00   0.50    0.70    --  101.75  45.00-150.00  160
 40  \w    135.00 160.00   0.50    0.70    --  101.75  77.00 120.00   50
 41  \w     93.00 173.00   0.50    0.70    --  101.75  45.00 120.00  160
 42  \w    146.00 171.00   0.50    0.70    --  101.75  77.00 150.00   50
 43  \w    143.00 171.00   0.50    0.70    --  101.75  77.00  90.00   56
 44  \w     94.00 173.00   0.50    0.70    --  101.75  45.00  90.00  158
 45  \w     81.00 107.00   0.50    0.70    --  101.75  77.00 120.00   52
 46  \w     81.00 107.00   0.50    0.70    --  101.75  77.00  60.00   52
 47  \w     81.00 107.00   0.50    0.70    --  101.75  77.00 150.00   52
 48  \w     74.00 100.00   0.50    0.70    --  101.75 -77.00-180.00   52
 49  \w     31.00  75.00   0.50    0.70    --  101.75 -61.00  30.00   88
 50  \w    137.00 164.00   0.50    0.70    --  101.75  61.00  60.00   54
 51  \w     81.00 107.00   0.50    0.70    --  101.75  77.00-150.00   52
 52  \w     88.00 114.00   0.50    0.70    --  101.75  61.00  60.00   52
 53  \w     81.00 107.00   0.50    0.70    --  101.75  77.00  90.00   52
 54  \w     34.00 107.00   0.50    0.70    --  101.75-125.00-180.00  146
 55  \w     30.00  75.00   0.50    0.70    --  101.75 -61.00  90.00   90
 56  \w   -110.00 -83.00   0.50    0.70    -- -103.00 -76.00 162.47   54
 57  \w   -109.00 -83.00   0.50    0.70    -- -103.00 -76.00 159.20   52
 58  \w   -109.00 -83.00   0.50    0.70    -- -103.00 -76.00-170.61   52
 59  \w   -112.00 -86.00   0.50    0.70    -- -103.00 -68.00 118.57   52
 60  \w   -136.00 -86.00   0.50    0.70    -- -103.00 -68.00  91.70  100
 61  \w   -121.00 -91.00   0.50    0.70    -- -103.00 -56.00 119.64   60
 62  \w   -108.00 -82.00   0.50    0.70    -- -103.00 -77.00 120.00   52
 63  \w   -110.00 -83.00   0.50    0.70    -- -103.00 -76.00-175.23   54
 64  \w   -109.00 -83.00   0.50    0.70    -- -103.00 -74.00-133.09   52
 65  \w   -173.00-147.00   0.50    0.70    -- -103.00 -76.00-175.23   52
 66  \w   -109.00 -84.00   0.50    0.70    -- -103.00 -72.00-129.67   50
 67  \w   -169.00-119.00   0.50    0.70    -- -103.00 -72.00-129.67  100
 68  \w   -111.00 -84.00   0.50    0.70    -- -103.00 -72.00-141.69   54
 69  \w    -62.00 -34.00   0.50    0.70    -- -103.00  61.00-180.00   56
 70  \w   -106.00 -80.00   0.50    0.70    -- -103.00 -83.00 107.29   52
 71  \w   -105.00 -80.00   0.50    0.70    -- -103.00 -81.00  96.34   50
 72  \w   -174.00-110.00   0.50    0.70    -- -103.00 -81.00  96.34  128
 73  \w   -108.00 -82.00   0.50    0.70    -- -103.00 -77.00-180.00   52
 74  \w   -107.00 -81.00   0.50    0.70    -- -103.00 -80.00-142.36   52
 75  \w   -109.00 -82.00   0.50    0.70    -- -103.00 -77.00 150.00   54
 76  \w   -123.00 -87.00   0.50    0.70    -- -103.00 -65.00 109.70   72
 77  \w   -130.00 -89.00   0.50    0.70    -- -103.00 -59.00-154.40   82
 78  \w   -170.00-145.00   0.50    0.70    -- -103.00 -77.00 150.00   50
 79  \w   -137.00 -90.00   0.50    0.70    -- -103.00 -56.00-148.83   94
 80  \w   -107.00 -81.00   0.50    0.70    -- -103.00 -79.00-152.59   52
 81  \w   -160.00-135.00   0.50    0.70    -- -103.00 -79.00-152.59   50
 82  \w   -108.00 -83.00   0.50    0.70    -- -103.00 -76.00 155.88   50
 83  \w   -172.00-146.00   0.50    0.70    -- -103.00 -76.00 155.88   52
 84  \w   -110.00 -81.00   0.50    0.70    -- -103.00 -83.00 119.79   58
 85  \w   -105.00 -80.00   0.50    0.70    -- -103.00 -81.00 121.51   50
 86  \w   -107.00 -80.00   0.50    0.70    -- -103.00 -83.00-132.34   54
 87  \w   -108.00 -81.00   0.50    0.70    -- -103.00 -79.00 176.50   54
 88  \w   -160.00-134.00   0.50    0.70    -- -103.00 -81.00 121.51   52
 89  \w   -108.00 -82.00   0.50    0.70    -- -103.00 -77.00-120.00   52
 90  \w   -114.00 -83.00   0.50    0.70    -- -103.00 -76.00 166.34   62
 91  \w    -59.00 -34.00   0.50    0.70    -- -103.00 125.00 150.00   50
 92  \w   -133.00 -91.00   0.50    0.70    -- -103.00 -57.00 118.00   84
 93  \w   -109.00 -83.00   0.50    0.70    -- -103.00 -74.00 148.63   52
 94  \w   -113.00 -86.00   0.50    0.70    -- -103.00 -68.00 135.58   54
 95  \w   -112.00 -85.00   0.50    0.70    -- -103.00 -71.00 128.66   54
 96  \w   -111.00 -85.00   0.50    0.70    -- -103.00 -71.00-174.97   52
 97  \w   -111.00 -80.00   0.50    0.70    -- -103.00 125.00 150.00   62
 98  \w   -113.00 -86.00   0.50    0.70    -- -103.00 -67.00-122.67   54
 99  \w   -108.00 -82.00   0.50    0.70    -- -103.00 -78.00 128.54   52
100  \w   -108.00 -81.00   0.50    0.70    -- -103.00 -80.00-158.83   54
101  \w   -174.00 -91.00   0.50    0.70    -- -103.00 -61.00-180.00  166
102  \w   -107.00 -80.00   0.50    0.70    -- -103.00 -82.00-143.42   54
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'XtaLAB Synergy R, DW system, HyPix'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      -0.0455100000
_diffrn_orient_matrix_UB_12      -0.0224081000
_diffrn_orient_matrix_UB_13      0.0350250000
_diffrn_orient_matrix_UB_21      0.0415654000
_diffrn_orient_matrix_UB_22      0.0114509000
_diffrn_orient_matrix_UB_23      0.0508230000
_diffrn_orient_matrix_UB_31      -0.0082918000
_diffrn_orient_matrix_UB_32      0.1814702000
_diffrn_orient_matrix_UB_33      0.0010802000
_diffrn_radiation_monochromator  mirror
_diffrn_radiation_probe          x-ray
_diffrn_radiation_type           'Cu K\a'
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.1107
_diffrn_reflns_av_unetI/netI     0.0435
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.982
_diffrn_reflns_limit_h_max       30
_diffrn_reflns_limit_h_min       -31
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -9
_diffrn_reflns_limit_l_max       31
_diffrn_reflns_limit_l_min       -31
_diffrn_reflns_number            60284
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.982
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         76.664
_diffrn_reflns_theta_min         3.540
_diffrn_source                   'Rotating-anode X-ray tube'
_diffrn_source_type              'Rigaku (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    3.364
_exptl_absorpt_correction_T_max  1.000
_exptl_absorpt_correction_T_min  0.411
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.43.101a (Rigaku Oxford Diffraction, 2023)
Numerical absorption correction based on gaussian integration over
a multifaceted crystal model
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.494
_exptl_crystal_description       needle
_exptl_crystal_F_000             2440
_exptl_crystal_recrystallization_method
'The material was recrystallised from --- by as supplied'
_exptl_crystal_size_max          0.353
_exptl_crystal_size_mid          0.066
_exptl_crystal_size_min          0.021
_refine_diff_density_max         0.598
_refine_diff_density_min         -0.922
_refine_diff_density_rms         0.103
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.082
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     361
_refine_ls_number_reflns         5429
_refine_ls_number_restraints     35
_refine_ls_restrained_S_all      1.087
_refine_ls_R_factor_all          0.0733
_refine_ls_R_factor_gt           0.0700
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1025P)^2^+11.8840P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1841
_refine_ls_wR_factor_ref         0.1875
_reflns_Friedel_coverage         0.000
_reflns_number_gt                5069
_reflns_number_total             5429
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5sc09994c1.cif
_cod_data_source_block           cx3273
_cod_depositor_comments
'Adding full bibliography for 1576448--1576450.cif.'
_cod_original_cell_volume        5244.8(2)
_cod_original_formula_sum        'C22.50 H25 Cl F3 N3 O6 S2'
_cod_database_code               1576449
_shelx_shelxl_version_number     2019/2
_chemical_oxdiff_formula         C22H24F3N3O6S2
_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. Restrained distances
 Cl1-C23 \\sim Cl1A-C23A
 with sigma of 0.02
3. Uiso/Uaniso restraints and constraints
Cl1 \\sim C23 \\sim Cl1A \\sim C23A: within 2A with sigma of 0.04 and sigma for
terminal atoms of 0.08 within 2A
4. Rigid body (RIGU) restrains
 Cl1, C23, Cl1A, C23A
 with sigma for 1-2 distances of 0.004 and sigma for 1-3 distances of 0.004
5. Others
 Sof(Cl1A)=1-FVAR(1)
 Sof(C23A)=Sof(H23C)=Sof(H23D)=0.5*(1-FVAR(2))
 Sof(C23)=Sof(H23A)=Sof(H23B)=0.5*FVAR(2)
 Sof(Cl1)=FVAR(1)
6.a Ternary CH refined with riding coordinates:
 C1(H1A)
6.b Secondary CH2 refined with riding coordinates:
 C3(H3A,H3B), C23(H23A,H23B), C23A(H23C,H23D)
6.c Aromatic/amide H refined with riding coordinates:
 C5(H5), C6(H6), C8(H8), C9(H9), C10(H10), C11(H11), C12(H12), C16(H16),
 C17(H17), C19(H19), C20(H20)
6.d Idealised Me refined as rotating group:
 C13(H13A,H13B,H13C), C14(H14A,H14B,H14C), C21(H21A,H21B,H21C)
;
_shelx_res_checksum              85754
_olex2_date_sample_data_collection 2024-01-23
_olex2_date_sample_submission    2024-01-22
_olex2_diffrn_ambient_temperature_device 'Oxford Cryosystems'
_olex2_exptl_crystal_mounting_method
'The crystal was mounted on a MITIGEN holder in paratone oil'
_olex2_submission_original_sample_id cx3273
_olex2_submission_special_instructions 'No special instructions were received'
_oxdiff_exptl_absorpt_empirical_details
;
Empirical correction (ABSPACK) includes:
- Absorption correction using spherical harmonics
- Frame scaling
;
_oxdiff_exptl_absorpt_empirical_full_max 1.881
_oxdiff_exptl_absorpt_empirical_full_min 0.380