Lewis acid-promoted intramolecular cyclization of ortho-prenylated chalcones: application to first total synthesis of (±) involucrasin C and its novel analogues
Ahamad, Jarish; Khatua, Rashmi Ranjan; Khan, Faiz Ahmed; RSC Advances 15 (2025) 27254–27259; doi:10.1039/D5RA04830C

data_7250752
_publ_section_title
;
 Lewis acid-promoted intramolecular cyclization of ortho-prenylated
 chalcones: application to first total synthesis of (+-) involucrasin C
 and its novel analogues
;
_journal_issue                   33
_journal_name_full               'RSC Advances'
_journal_page_first              27254
_journal_page_last               27259
_journal_paper_doi               10.1039/D5RA04830C
_journal_volume                  15
_journal_year                    2025
_chemical_formula_moiety         'C48 H46 O6'
_chemical_formula_sum            'C48 H46 O6'
_chemical_formula_weight         718.85
_space_group_crystal_system      triclinic
_space_group_IT_number           2
_space_group_name_Hall           '-P 1'
_space_group_name_H-M_alt        'P -1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     dual
_audit_creation_date             2025-01-23
_audit_creation_method
;
Olex2 1.5-alpha
(compiled 2025.01.10 svn.r16582094 for OlexSys, GUI svn.r7115)
;
_audit_update_record
;
2025-02-15 deposited with the CCDC.	2025-07-18 downloaded from the CCDC.
;
_cell_angle_alpha                104.078(5)
_cell_angle_beta                 95.959(5)
_cell_angle_gamma                95.907(5)
_cell_formula_units_Z            2
_cell_length_a                   5.9062(8)
_cell_length_b                   14.2368(19)
_cell_length_c                   23.850(3)
_cell_measurement_reflns_used    3009
_cell_measurement_temperature    298
_cell_measurement_theta_max      23.696
_cell_measurement_theta_min      2.594
_cell_volume                     1917.5(4)
_computing_cell_refinement       'SAINT V8.40B (?, 2016)'
_computing_data_reduction        'SAINT V8.40B (?, 2016)'
_computing_molecular_graphics    'Olex2 1.5-alpha (Dolomanov et al., 2009)'
_computing_publication_material  'Olex2 1.5-alpha (Dolomanov et al., 2009)'
_computing_structure_refinement  'XL  (Sheldrick, 2008)'
_computing_structure_solution    'SHELXT 2018/2 (Sheldrick, 2018)'
_diffrn_ambient_temperature      298
_diffrn_measured_fraction_theta_full 0.999
_diffrn_measured_fraction_theta_max 0.999
_diffrn_measurement_device_type  'Bruker APEX-V Photon II'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.1185
_diffrn_reflns_av_unetI/netI     0.0897
_diffrn_reflns_Laue_measured_fraction_full 0.999
_diffrn_reflns_Laue_measured_fraction_max 0.999
_diffrn_reflns_limit_h_max       7
_diffrn_reflns_limit_h_min       -6
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       28
_diffrn_reflns_limit_l_min       -28
_diffrn_reflns_number            37662
_diffrn_reflns_point_group_measured_fraction_full 0.999
_diffrn_reflns_point_group_measured_fraction_max 0.999
_diffrn_reflns_theta_full        25.000
_diffrn_reflns_theta_max         25.000
_diffrn_reflns_theta_min         1.919
_diffrn_source_current           1.4
_diffrn_source_power             0.07
_diffrn_source_voltage           50.0
_exptl_absorpt_coefficient_mu    0.081
_exptl_absorpt_correction_T_max  0.7455
_exptl_absorpt_correction_T_min  0.5744
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
SADABS-2016/2 (Bruker,2016/2) was used for absorption correction.
wR2(int) was 0.1566 before and 0.0712 after correction.
The Ratio of minimum to maximum transmission is 0.7705.
The \l/2 correction factor is Not present.
;
_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    1.245
_exptl_crystal_description       block
_exptl_crystal_F_000             764
_exptl_crystal_recrystallization_method
'The material was recrystallised from a mixture of hexane and CH3CN  by slow evaporation'
_exptl_crystal_size_max          0.12
_exptl_crystal_size_mid          0.09
_exptl_crystal_size_min          0.06
_refine_diff_density_max         0.153
_refine_diff_density_min         -0.188
_refine_diff_density_rms         0.038
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.008
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     490
_refine_ls_number_reflns         6719
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.008
_refine_ls_R_factor_all          0.1540
_refine_ls_R_factor_gt           0.0565
_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^)+(0.0520P)^2^+0.4134P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1164
_refine_ls_wR_factor_ref         0.1589
_reflns_Friedel_coverage         0.000
_reflns_number_gt                3168
_reflns_number_total             6719
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            d5ra04830c2.cif
_cod_data_source_block           mo_fak_ja_exp_743_b
_cod_original_cell_volume        1917.5(5)
_cod_database_code               7250752
_shelx_shelxl_version_number     2017/1
_shelx_estimated_absorpt_t_max   0.995
_shelx_estimated_absorpt_t_min   0.990
_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.a Ternary CH refined with riding coordinates:
 C23(H23), C22(H22)
2.b Secondary CH2 refined with riding coordinates:
 C35(H35A,H35B), C27(H27A,H27B), C8(H8A,H8B), C42(H42A,H42B), C1(H1A,H1B),
 C21(H21A,H21B)
2.c Aromatic/amide H refined with riding coordinates:
 C38(H38), C37(H37), C36(H36), C33(H33), C34(H34), C10(H10), C11(H11),
 C12(H12), C40(H40), C39(H39), C31(H31), C44(H44), C45(H45), C46(H46), C47(H47),
  C48(H48), C17(H17), C16(H16), C13(H13), C14(H14), C7(H7), C6(H6), C5(H5),
 C4(H4), C3(H3A)
2.d Idealised Me refined as rotating group:
 C26(H26A,H26B,H26C), C25(H25A,H25B,H25C)
2.e Idealised tetrahedral OH refined as rotating group:
 O3(H3)
;
_shelx_res_checksum              48491
_shelx_hkl_checksum              57528
_olex2_exptl_crystal_mounting_method 'Nylon loop used'
_olex2_submission_special_instructions 'No special instructions were received'