Synthetic Study of 1,3-Butadiene-Based IMDA Approach to Construct a [5-7-6] Tricyclic Core and Its Application to the Total Synthesis of C8-epi-Guanacastepene O
Chuang-Chuang Li; Cui-Hua Wang; Bo Liang; Xin-Hao Zhang; Lu-Jiang Deng; Shuang Liang; Jia-Hua Chen; Yun-Dong Wu; Zhen Yang; Journal of Organic Chemistry 71 (2006) 6892–6897; doi:10.1021/jo060996h

data_4021939
_publ_section_title
;
 Synthetic Study of 1,3-Butadiene-Based IMDA Approach to Construct
 a [5-7-6] Tricyclic Core and Its Application to the Total Synthesis
 of C8-epi-Guanacastepene O
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              6892
_journal_page_last               6897
_journal_paper_doi               10.1021/jo060996h
_journal_volume                  71
_journal_year                    2006
_chemical_formula_sum            'C18 H20 O4'
_chemical_formula_weight         300.34
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
_audit_creation_method           SHELXL-97
_cell_angle_alpha                90.00
_cell_angle_beta                 99.99(3)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   10.019(2)
_cell_length_b                   9.0397(18)
_cell_length_c                   17.986(4)
_cell_measurement_reflns_used    12916
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.48
_cell_measurement_theta_min      2.30
_cell_volume                     1604.3(6)
_computing_cell_refinement       Rapid-AUTO
_computing_data_collection       'Rapid-AUTO (Rigaku,2000)'
_computing_data_reduction        'CrystalStructure (Rigaku/MSC,2000)'
_computing_molecular_graphics    'Siemens SHELXTL V4.2,(Sheldrick,1990)'
_computing_publication_material  SHELXL-97,(Sheldrick,1997)
_computing_structure_refinement  SHELXL-97,(Sheldrick,1997)
_computing_structure_solution    SHELXS-97,(Sheldrick,1997)
_diffrn_ambient_temperature      293(2)
_diffrn_detector_area_resol_mean 10.00
_diffrn_measured_fraction_theta_full 0.996
_diffrn_measured_fraction_theta_max 0.996
_diffrn_measurement_device_type  'Rigaku RAXIS RAPID IP'
_diffrn_measurement_method       \W
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'fine-focus sealed tube'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0325
_diffrn_reflns_av_sigmaI/netI    0.0547
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -11
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -23
_diffrn_reflns_number            12916
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_diffrn_reflns_theta_min         2.30
_diffrn_standards_decay_%        0
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.087
_exptl_absorpt_correction_T_max  0.983
_exptl_absorpt_correction_T_min  0.957
_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details
;
                                   HIGASHI, T. (1995). Abscor-Empirical
                                   Absorption Correction based on Fourier
                                   Series Approximation.
                                   Rigaku Corporation,Tokyo,Japan.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.244
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             640
_exptl_crystal_size_max          0.50
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.262
_refine_diff_density_min         -0.205
_refine_diff_density_rms         0.036
_refine_ls_extinction_coef       0.027(2)
_refine_ls_extinction_expression Fc^*^=kFc[1+0.001xFc^2^\l^3^/sin(2\q)]^-1/4^
_refine_ls_extinction_method     SHELXL
_refine_ls_goodness_of_fit_ref   0.994
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     200
_refine_ls_number_reflns         3662
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.994
_refine_ls_R_factor_all          0.0871
_refine_ls_R_factor_gt           0.0430
_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0450P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0992
_refine_ls_wR_factor_ref         0.1063
_reflns_number_gt                1890
_reflns_number_total             3662
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo060996hsi20060518_030801.cif
_cod_original_sg_symbol_H-M      'P 21/n'
_cod_database_code               4021939