Synthesis of 1,4-naphthoquinone methides via acid-catalyzed cascade cyclizations of benzannulated enediynyl alcohols.
Wen, Bo; Petersen, Jeffrey L.; Wang, Kung K.; Organic letters 13 (2011) 168–171; doi:10.1021/ol102793a

data_1501909
_publ_section_title
;
 Synthesis of 1,4-naphthoquinone methides via acid-catalyzed cascade
 cyclizations of benzannulated enediynyl alcohols.
;
_journal_issue                   1
_journal_name_full               'Organic letters'
_journal_page_first              168
_journal_page_last               171
_journal_paper_doi               10.1021/ol102793a
_journal_volume                  13
_journal_year                    2011
_chemical_formula_sum            'C28 H24 O2'
_chemical_formula_weight         392.47
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_atom_sites_solution_primary     direct
_atom_sites_solution_secondary   difmap
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_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   11.083(1)
_cell_length_b                   12.964(1)
_cell_length_c                   14.977(1)
_cell_measurement_reflns_used    7932
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      27.41
_cell_measurement_theta_min      2.28
_cell_volume                     2151.9(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 0.994
_diffrn_measured_fraction_theta_max 0.994
_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  0.0365
_diffrn_reflns_av_sigmaI/netI    0.0586
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -14
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -16
_diffrn_reflns_limit_l_max       18
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            14647
_diffrn_reflns_theta_full        27.41
_diffrn_reflns_theta_max         27.41
_diffrn_reflns_theta_min         2.29
_diffrn_standards_decay_%        none
_exptl_absorpt_coefficient_mu    0.075
_exptl_absorpt_correction_T_max  0.981
_exptl_absorpt_correction_T_min  0.967
_exptl_absorpt_correction_type   semi-empirical
_exptl_absorpt_process_details   SADABS
_exptl_crystal_colour            yellow
_exptl_crystal_density_diffrn    1.211
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             832
_exptl_crystal_size_max          0.45
_exptl_crystal_size_mid          0.42
_exptl_crystal_size_min          0.26
_refine_diff_density_max         0.136
_refine_diff_density_min         -0.135
_refine_diff_density_rms         0.033
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.2(15)
_refine_ls_extinction_method     none
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_refine_ls_matrix_type           full
_refine_ls_number_parameters     274
_refine_ls_number_reflns         4853
_refine_ls_number_restraints     0
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_refine_ls_R_factor_all          0.0512
_refine_ls_R_factor_gt           0.0429
_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^)+(0.0492P)^2^+0.165P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1104
_refine_ls_wR_factor_ref         0.1177
_reflns_number_gt                4171
_reflns_number_total             4853
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol102793a_si_002.cif
_cod_data_source_block           bw13ccd
_cod_original_cell_volume        2152.0(3)
_cod_original_sg_symbol_H-M      P212121
_cod_database_code               1501909