Synthesis of Chromones from 1,1-Diacylcyclopropanes: Toward the Synthesis of Bromophycoic Acid E.
Smith, Robert J.; Nhu, Duong; Clark, Mitchell R.; Gai, Sinan; Lucas, Nigel T.; Hawkins, Bill C.; The Journal of organic chemistry 82 (2017) 5317–5327; doi:10.1021/acs.joc.7b00648

data_4032523
_publ_section_title
;
 Synthesis of Chromones from 1,1-Diacylcyclopropanes: Toward the Synthesis
 of Bromophycoic Acid E.
;
_journal_issue                   10
_journal_name_full               'The Journal of organic chemistry'
_journal_page_first              5317
_journal_page_last               5327
_journal_paper_doi               10.1021/acs.joc.7b00648
_journal_volume                  82
_journal_year                    2017
_chemical_formula_moiety         'C19 H16 O3'
_chemical_formula_sum            'C19 H16 O3'
_chemical_formula_weight         292.32
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2yn'
_space_group_name_H-M_alt        'P 1 21/n 1'
_symmetry_space_group_name_Hall  '-P 2yn'
_symmetry_space_group_name_H-M   'P 1 21/n 1'
_atom_sites_solution_hydrogens   geom
_audit_block_code                ntl1602
_audit_creation_method           SHELXL-2014/7
_cell_angle_alpha                90
_cell_angle_beta                 101.919(2)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   10.8211(2)
_cell_length_b                   7.3341(2)
_cell_length_c                   18.3161(4)
_cell_measurement_reflns_used    6377
_cell_measurement_temperature    100(1)
_cell_measurement_theta_max      74.185
_cell_measurement_theta_min      4.166
_cell_volume                     1422.28(6)
_computing_structure_refinement  'SHELXL-2014/7 (Sheldrick, 2014)'
_diffrn_ambient_temperature      100(1)
_diffrn_crystal_treatment
; 
Crystal was attached with Paratone N oil to a 0.3 mm CryoLoop supported 
in a copper mounting pin, then quenched in a cold nitrogen gas from a gas
stream from an Oxford Cryosystems Cryostream.
;
_diffrn_detector_area_resol_mean 5.1725
_diffrn_measured_fraction_theta_full 0.991
_diffrn_measured_fraction_theta_max 0.962
_diffrn_measurement_device_type  'SuperNova, Dual, Cu at zero, Atlas'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_source         'SuperNova (Cu) X-ray Source'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54184
_diffrn_reflns_av_R_equivalents  0.0228
_diffrn_reflns_av_unetI/netI     0.0182
_diffrn_reflns_Laue_measured_fraction_full 0.991
_diffrn_reflns_Laue_measured_fraction_max 0.962
_diffrn_reflns_limit_h_max       13
_diffrn_reflns_limit_h_min       -13
_diffrn_reflns_limit_k_max       6
_diffrn_reflns_limit_k_min       -8
_diffrn_reflns_limit_l_max       22
_diffrn_reflns_limit_l_min       -21
_diffrn_reflns_number            7916
_diffrn_reflns_point_group_measured_fraction_full 0.991
_diffrn_reflns_point_group_measured_fraction_max 0.962
_diffrn_reflns_theta_full        67.000
_diffrn_reflns_theta_max         74.181
_diffrn_reflns_theta_min         4.936
_exptl_absorpt_coefficient_mu    0.740
_exptl_absorpt_correction_T_max  0.922
_exptl_absorpt_correction_T_min  0.850
_exptl_absorpt_correction_type   gaussian
_exptl_absorpt_process_details
;
CrysAlisPro, Agilent Technologies,Version 1.171.37.33
Numerical absorption correction based on gaussian integration over
a multifaceted crystal model. Empirical absorption correction using 
spherical harmonics,implemented in SCALE3 ABSPACK 
scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.365
_exptl_crystal_description       block
_exptl_crystal_F_000             616
_exptl_crystal_size_max          0.310
_exptl_crystal_size_mid          0.260
_exptl_crystal_size_min          0.140
_refine_diff_density_max         0.288
_refine_diff_density_min         -0.213
_refine_diff_density_rms         0.046
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.045
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     200
_refine_ls_number_reflns         2794
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.045
_refine_ls_R_factor_all          0.0419
_refine_ls_R_factor_gt           0.0401
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.0678P)^2^+0.4937P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1097
_refine_ls_wR_factor_ref         0.1117
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2622
_reflns_number_total             2794
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            jo7b00648_si_002.cif
_cod_data_source_block           27a
_cod_database_code               4032523
_shelx_shelxl_version_number     2014/7
_shelx_estimated_absorpt_t_min   0.803
_shelx_estimated_absorpt_t_max   0.904
_shelx_hkl_checksum              30503