Biosynthesis inspired asymmetric total synthesis of camptothecin.
Li, Shan-Shan; Wu, Xiao-Guang; Li, Zhen; Tian, Jin-Rui; Ma, Ai-Jun; Tu, Yong-Qiang; Chemical communications (Cambridge, England) 62 (2026) 1276–1279; doi:10.1039/d5cc06451a

data_7135505
_publ_section_title
;
 Biosynthesis inspired asymmetric total synthesis of camptothecin.
;
_journal_issue                   4
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              1276
_journal_page_last               1279
_journal_paper_doi               10.1039/d5cc06451a
_journal_volume                  62
_journal_year                    2026
_chemical_absolute_configuration ad
_chemical_formula_moiety         'C28 H38 N2 O6 Si'
_chemical_formula_sum            'C28 H38 N2 O6 Si'
_chemical_formula_weight         526.69
_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'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_block_doi                 10.5517/ccdc.csd.cc2pgtss
_audit_creation_date             2025-09-03
_audit_creation_method
;
Olex2 1.5
(compiled 2025.07.13 svn.rb7424aed for OlexSys, GUI svn.r7308)
;
_audit_update_record
;
2025-09-10 deposited with the CCDC.	2025-12-07 downloaded from the CCDC.
;
_cell_angle_alpha                90
_cell_angle_beta                 95.1100(10)
_cell_angle_gamma                90
_cell_formula_units_Z            12
_cell_length_a                   12.00550(10)
_cell_length_b                   18.7238(2)
_cell_length_c                   40.9353(5)
_cell_measurement_reflns_used    28639
_cell_measurement_temperature    173.00(13)
_cell_measurement_theta_max      76.0090
_cell_measurement_theta_min      2.6000
_cell_volume                     9165.22(17)
_computing_cell_refinement       'CrysAlisPro 1.171.43.143a (Rigaku OD, 2024)'
_computing_data_collection       'CrysAlisPro 1.171.43.143a (Rigaku OD, 2024)'
_computing_data_reduction        'CrysAlisPro 1.171.43.143a (Rigaku OD, 2024)'
_computing_molecular_graphics    'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5 (Dolomanov et al., 2009)'
_computing_structure_refinement  'SHELXL 2018/3 (Sheldrick, 2015)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_environment      N~2~
_diffrn_ambient_temperature      173.00(13)
_diffrn_detector                 'Hybrid Pixel Array Detector'
_diffrn_detector_area_resol_mean 10.0000
_diffrn_detector_type            HyPix
_diffrn_measured_fraction_theta_full 0.992
_diffrn_measured_fraction_theta_max 0.939
_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     40.00  66.00   0.50    0.40    --  108.90 -61.00 150.00   52
  2  \w     39.00  95.00   0.50    0.40    --  108.90 -77.00  90.00  112
  3  \w     35.00  60.00   0.50    0.40    --  108.90 -61.00  30.00   50
  4  \w    -28.00  33.00   0.50    0.10    --   44.66 -57.00  84.00  122
  5  \w     36.00  62.00   0.50    0.40    --  108.90 -57.00  84.00   52
  6  \w     42.00  67.00   0.50    0.40    --  108.90 -61.00 -30.00   50
  7  \w    -28.00  24.00   0.50    0.10    --   44.66 -19.00 -90.00  104
  8  \w     39.00  64.00   0.50    0.40    --  108.90 -61.00-150.00   50
  9  \w    147.00 173.00   0.50    0.40    --  108.90  57.00-134.00   52
 10  \w     89.00 143.00   0.50    0.40    --  108.90  57.00-134.00  108
 11  \w     25.00 114.00   0.50    0.10    --   44.66  57.00-134.00  178
 12  \w    101.00 175.00   0.50    0.40    --  108.90  45.00 150.00  148
 13  \w    -30.00  33.00   0.50    0.10    --  -44.66  19.00-150.00  126
 14  \w    -40.00  -2.00   0.50    0.10    --  -44.66  57.00-134.00   76
 15  \w    -69.00 -28.00   0.50    0.40    -- -100.00  57.00-134.00   82
 16  \w    -73.00 -26.00   0.50    0.40    -- -100.00  61.00 -90.00   94
 17  \w    -53.00 -26.00   0.50    0.40    -- -100.00  45.00 -30.00   54
 18  \w    -51.00 -26.00   0.50    0.40    -- -100.00  45.00   0.00   50
 19  \w    -58.00 -33.00   0.50    0.40    -- -100.00  61.00  60.00   50
 20  \w    -52.00 -25.00   0.50    0.40    -- -100.00  45.00  90.00   54
 21  \w    -54.00 -29.00   0.50    0.40    -- -100.00  45.00  60.00   50
 22  \w    -51.00 -25.00   0.50    0.40    -- -100.00  45.00-180.00   52
 23  \w   -174.00-122.00   0.50    0.40    -- -100.00 -45.00 -30.00  104
 24  \w   -151.00-126.00   0.50    0.40    -- -100.00 -57.00  84.00   50
 25  \w   -174.00-147.00   0.50    0.40    -- -100.00 -61.00 150.00   54
 26  \w   -131.00 -82.00   0.50    0.40    -- -100.00 -61.00 150.00   98
 27  \w    -95.00 -70.00   0.50    0.10    --  -44.66 -57.00  84.00   50
 28  \w   -115.00 -79.00   0.50    0.40    -- -100.00 -45.00 -30.00   72
 29  \w   -159.00-133.00   0.50    0.40    -- -100.00 -77.00-150.00   52
 30  \w   -164.00-135.00   0.50    0.40    -- -100.00-125.00-120.00   58
 31  \w   -108.00 -82.00   0.50    0.40    -- -100.00-125.00-120.00   52
;
_diffrn_measurement_device       'four-circle diffractometer'
_diffrn_measurement_device_type  'ROD, Synergy Custom system, HyPix'
_diffrn_measurement_method       '\w scans'
_diffrn_orient_matrix_type
'CrysAlisPro convention (1999,Acta A55,543-557)'
_diffrn_orient_matrix_UB_11      0.0178242000
_diffrn_orient_matrix_UB_12      0.0506627000
_diffrn_orient_matrix_UB_13      -0.0287348000
_diffrn_orient_matrix_UB_21      -0.1128250000
_diffrn_orient_matrix_UB_22      -0.0238073000
_diffrn_orient_matrix_UB_23      -0.0175107000
_diffrn_orient_matrix_UB_31      -0.0596392000
_diffrn_orient_matrix_UB_32      0.0602394000
_diffrn_orient_matrix_UB_33      0.0172219000
_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  0.0491
_diffrn_reflns_av_unetI/netI     0.0556
_diffrn_reflns_Laue_measured_fraction_full 0.992
_diffrn_reflns_Laue_measured_fraction_max 0.939
_diffrn_reflns_limit_h_max       14
_diffrn_reflns_limit_h_min       -15
_diffrn_reflns_limit_k_max       23
_diffrn_reflns_limit_k_min       -21
_diffrn_reflns_limit_l_max       51
_diffrn_reflns_limit_l_min       -51
_diffrn_reflns_number            65421
_diffrn_reflns_point_group_measured_fraction_full 0.820
_diffrn_reflns_point_group_measured_fraction_max 0.760
_diffrn_reflns_theta_full        67.684
_diffrn_reflns_theta_max         76.208
_diffrn_reflns_theta_min         2.167
_diffrn_source                   'Rotating-anode X-ray tube'
_diffrn_source_type              'Rigaku (Cu) X-ray Source'
_exptl_absorpt_coefficient_mu    1.006
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.39379
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro 1.171.43.143a (Rigaku Oxford Diffraction, 2024)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            'clear light colourless'
_exptl_crystal_colour_lustre     clear
_exptl_crystal_colour_modifier   light
_exptl_crystal_colour_primary    colourless
_exptl_crystal_density_diffrn    1.145
_exptl_crystal_description       block
_exptl_crystal_F_000             3384
_exptl_crystal_size_max          0.12
_exptl_crystal_size_mid          0.11
_exptl_crystal_size_min          0.07
_refine_diff_density_max         0.610
_refine_diff_density_min         -0.338
_refine_diff_density_rms         0.063
_refine_ls_abs_structure_details
;
 Flack x determined using 8419 quotients [(I+)-(I-)]/[(I+)+(I-)]
 (Parsons, Flack and Wagner, Acta Cryst. B69 (2013) 249-259).
;
_refine_ls_abs_structure_Flack   0.068(14)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.818
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     2047
_refine_ls_number_reflns         29167
_refine_ls_number_restraints     25
_refine_ls_restrained_S_all      0.821
_refine_ls_R_factor_all          0.0662
_refine_ls_R_factor_gt           0.0608
_refine_ls_shift/su_max          0.007
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1586P)^2^+3.4976P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1693
_refine_ls_wR_factor_ref         0.1770
_reflns_Friedel_coverage         0.570
_reflns_Friedel_fraction_full    0.637
_reflns_Friedel_fraction_max     0.570
_reflns_number_gt                25849
_reflns_number_total             29167
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5cc06451a2.cif
_cod_data_source_block           lishansha_0829_1_auto
_cod_database_code               7135505
_shelx_shelxl_version_number     2018/3
_shelx_estimated_absorpt_t_max   0.933
_shelx_estimated_absorpt_t_min   0.889
_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. Uiso/Uaniso restraints and constraints
Uanis(C066) \\sim Ueq, Uanis(C062) \\sim Ueq, Uanis(C8) \\sim Ueq, Uanis(C6)
\\sim Ueq: with sigma of 0.01 and sigma for terminal atoms of 0.02
3.a Ternary CH refined with riding coordinates:
 C01E(H01E), C01O(H01O), C01P(H01P), C01Q(H01Q), C01U(H01U), C01W(H01W),
 C022(H022), C025(H025), C026(H026), C028(H028), C029(H029), C02M(H02S),
 C02N(H02W), C02O(H02X), C02U(H02U), C02Y(H02Z), C031(H031), C034(H034),
 C035(H035), C038(H038), C03F(H9), C03P(H3), C03Q(H4), C03R(H10)
3.b Secondary CH2 refined with riding coordinates:
 C01R(H01A,H01B), C020(H02T,H02V), C023(H02L,H02M), C02A(H02H,H02I), C02F(H02J,
 H02K), C02G(H02N,H02O), C02L(H02D,H02E), C02V(H02Y,H), C02X(H02F,H02G),
 C036(H8,HC), C03H(H03,HD), C03O(H03P,H03Q), C04C(H12,HM), C04H(H5,HN),
 C04L(H04T,H04U), C04V(H2,HS), C04W(H13,HT), C04Y(H04L,H04M), C051(H14,HW),
 C054(H05G,H05H), C055(H23,HZ), C05E(H05S,H05T), C05F(H05U,H05V), C05P(H29,H40)
3.c Aromatic/amide H refined with riding coordinates:
 C03G(H03U), C03W(H03Y), C03X(H03Z), C042(H042), C044(H044), C045(H045),
 C04D(H04R), C04F(H04F), C04G(H04S), C04I(H04I), C04P(H04P), C04Z(H04Z),
 C053(H053), C05A(H25), C05B(H26), C05C(H05R), C05I(H05W), C05J(H16),
 C05L(H05X), C05N(H05Y), C05O(H17), C05S(H30), C05T(H31), C05V(H19)
3.d Idealised Me refined as rotating group:
 C02H(H02P,H02Q,H02R), C02J(H02A,H02B,H02C), C02Z(H02,HA,HB), C039(H03G,H03H,
 H03I), C03I(H03V,H03W,H03X), C03J(H03J,H03K,H03L), C03K(H03A,H03B,H03C),
 C03L(H03M,H03N,H03O), C03N(H21,HE,HF), C03S(H03R,H03S,H03T), C03U(H11,HG,HH),
 C03Y(H03D,H03E,H03F), C040(H04N,H04O,H04Q), C043(H04Y,HI,HJ), C048(H04,HK,HL),
 C049(H04A,H04B,H04C), C04K(H04D,H04E,H04G), C04O(H04V,H04W,H04X), C04S(H6,HO,
 HP), C04T(H04H,H04J,H04K), C04U(H1,HQ,HR), C04X(H7,HU,HV), C050(H05O,H05P,
 H05Q), C052(H22,HX,HY), C057(H15,H32,H33), C058(H24,H34,H35), C05D(H27,H36,
 H37), C05G(H05D,H05E,H05F), C05K(H28,H38,H39), C05M(H05I,H05J,H05K), C05Q(H05A,
 H05B,H05C), C05R(H18,H41,H42), C05U(H05Z,H43,H44), C05W(H05,H45,H46), C05X(H20,
 H47,H48), C05Z(H05L,H05M,H05N), C060(H06J,H06K,H06L), C063(H06A,H06B,H06C),
 C065(H06D,H06E,H06F), C066(H06G,H06H,H06I), C6(H6A,H6B,H6C), C8(H8A,H8B,H8C)
3.e Idealised tetrahedral OH refined as rotating group:
 O00A(H00A), O00C(H00C), O00E(H00E), O00K(H00K), O00M(H00M), O00O(H00O)
;
_smtbx_masks_void_probe_radius   1.2
_smtbx_masks_void_truncation_radius 1.2
_shelx_res_checksum              53119
_shelx_hkl_checksum              94026
_shelx_fab_checksum              9732
_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 1.713
_oxdiff_exptl_absorpt_empirical_full_min 0.497