Total synthesis of (−)-8-epi-chromazonarol enabled by a unique N2H4·H2O promoted intramolecular oxa-Michael cyclization reaction
Liu, Lin; Song, Huayue; Chen, Peng; Yuan, Ziyun; Feng, Shangbiao; Zhang, Weiwei; Fang, Bowen; Xie, Xingang; She, Xuegong; Organic Chemistry Frontiers 5 (2018) 3013–; doi:10.1039/C8QO00901E

data_1554448
_publ_section_title
;
 Total synthesis of (&#x2212;)-8-epi-chromazonarol enabled by a unique
 N2H4&#x00B7;H2O promoted intramolecular oxa-Michael cyclization reaction
;
_journal_issue                   20
_journal_name_full               'Organic Chemistry Frontiers'
_journal_page_first              3013
_journal_paper_doi               10.1039/C8QO00901E
_journal_volume                  5
_journal_year                    2018
_chemical_formula_sum            'C28 H33 Br O3'
_chemical_formula_weight         497.45
_space_group_IT_number           5
_space_group_name_Hall           'I 2y'
_space_group_name_H-M_alt        'I 1 2 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_audit_update_record
;
2018-07-12 deposited with the CCDC.
2018-09-17 downloaded from the CCDC.
;
_cell_angle_alpha                90.00
_cell_angle_beta                 92.458(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   26.3570(8)
_cell_length_b                   7.5712(3)
_cell_length_c                   24.9141(8)
_cell_measurement_temperature    293(2)
_cell_volume                     4967.1(3)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      293(2)
_diffrn_measured_fraction_theta_full 0.984
_diffrn_measured_fraction_theta_max 0.984
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0188
_diffrn_reflns_av_sigmaI/netI    0.0266
_diffrn_reflns_limit_h_max       31
_diffrn_reflns_limit_h_min       -31
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -5
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -29
_diffrn_reflns_number            10380
_diffrn_reflns_theta_full        66.60
_diffrn_reflns_theta_max         66.60
_diffrn_reflns_theta_min         3.55
_exptl_absorpt_coefficient_mu    2.456
_exptl_crystal_density_diffrn    1.330
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             2080
_refine_diff_density_max         0.819
_refine_diff_density_min         -0.480
_refine_diff_density_rms         0.050
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.02(2)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.974
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     585
_refine_ls_number_reflns         6327
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      0.974
_refine_ls_R_factor_all          0.0497
_refine_ls_R_factor_gt           0.0468
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0904P)^2^+4.2082P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1352
_refine_ls_wR_factor_ref         0.1402
_reflns_number_gt                5918
_reflns_number_total             6327
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c8qo00901e2.cif
_cod_data_source_block           liuc_0410
_cod_original_cell_volume        4967.2(3)
_cod_database_code               1554448