Sequential Ketene Generation from Dioxane-4,6-dione-keto-dioxinones for the Synthesis of Terpenoid Resorcylates.
Elliott, Daniel C.; Ma, Tsz-Kan; Selmani, Aymane; Cookson, Rosa; Parsons, Philip J.; Barrett, Anthony G. M.; Organic letters 18 (2016) 1800–1803; doi:10.1021/acs.orglett.6b00533

data_1555514
_publ_section_title
;
 Sequential Ketene Generation from Dioxane-4,6-dione-keto-dioxinones for
 the Synthesis of Terpenoid Resorcylates.
;
_journal_issue                   8
_journal_name_full               'Organic letters'
_journal_page_first              1800
_journal_page_last               1803
_journal_paper_doi               10.1021/acs.orglett.6b00533
_journal_volume                  18
_journal_year                    2016
_chemical_formula_moiety         'C21 H28 O4'
_chemical_formula_sum            'C21 H28 O4'
_chemical_formula_weight         344.43
_space_group_crystal_system      monoclinic
_space_group_IT_number           14
_space_group_name_Hall           '-P 2ybc'
_space_group_name_H-M_alt        'P 1 21/c 1'
_atom_sites_solution_hydrogens   mixed
_audit_creation_method           SHELXL
_cell_angle_alpha                90
_cell_angle_beta                 94.596(7)
_cell_angle_gamma                90
_cell_formula_units_Z            4
_cell_length_a                   15.5552(10)
_cell_length_b                   15.6415(10)
_cell_length_c                   8.1031(7)
_cell_measurement_reflns_used    1242
_cell_measurement_temperature    173
_cell_measurement_theta_max      27.7690
_cell_measurement_theta_min      2.9970
_cell_volume                     1965.2(2)
_computing_cell_refinement       'CrysAlisPro, Agilent Technologies'
_computing_data_collection       'CrysAlisPro, Agilent Technologies'
_computing_data_reduction        'CrysAlisPro, Agilent Technologies'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'CIFTAB-2013 (Sheldrick, 2013)'
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
_computing_structure_solution    'SHELXS-2013 (Sheldrick, 2013)'
_diffrn_ambient_temperature      173
_diffrn_detector_area_resol_mean 16.0382
_diffrn_measured_fraction_theta_full 0.987
_diffrn_measured_fraction_theta_max 0.803
_diffrn_measurement_device_type  'Agilent Xcalibur 3 E'
_diffrn_measurement_method       'omega scans'
_diffrn_radiation_type           MoK\a
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.0510
_diffrn_reflns_av_unetI/netI     0.0976
_diffrn_reflns_Laue_measured_fraction_full 0.987
_diffrn_reflns_Laue_measured_fraction_max 0.803
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -17
_diffrn_reflns_limit_k_max       19
_diffrn_reflns_limit_k_min       -20
_diffrn_reflns_limit_l_max       5
_diffrn_reflns_limit_l_min       -9
_diffrn_reflns_number            7041
_diffrn_reflns_point_group_measured_fraction_full 0.987
_diffrn_reflns_point_group_measured_fraction_max 0.803
_diffrn_reflns_theta_full        25.242
_diffrn_reflns_theta_max         28.318
_diffrn_reflns_theta_min         2.604
_diffrn_source                   'Enhance (Mo) X-ray Source'
_exptl_absorpt_coefficient_mu    0.079
_exptl_absorpt_correction_T_max  0.998
_exptl_absorpt_correction_T_min  0.974
_exptl_absorpt_correction_type   analytical
_exptl_absorpt_process_details
;
CrysAlisPro, Agilent Technologies,
Version 1.171.37.35 (release 13-08-2014 CrysAlis171 .NET)
(compiled Aug 13 2014,18:06:01)
Analytical numeric absorption correction using a multifaceted crystal
model based on expressions derived by R.C. Clark & J.S. Reid.
(Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            Colourless
_exptl_crystal_density_diffrn    1.164
_exptl_crystal_description       'thin plates'
_exptl_crystal_F_000             744
_exptl_crystal_size_max          0.64
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.02
_refine_diff_density_max         0.272
_refine_diff_density_min         -0.300
_refine_diff_density_rms         0.065
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.002
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     236
_refine_ls_number_reflns         3936
_refine_ls_number_restraints     1
_refine_ls_restrained_S_all      1.002
_refine_ls_R_factor_all          0.1377
_refine_ls_R_factor_gt           0.0751
_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^)+(0.0887P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1638
_refine_ls_wR_factor_ref         0.2066
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2179
_reflns_number_total             3936
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol6b00533_si_003.cif
_cod_data_source_block           3h
_cod_original_sg_symbol_H-M      'P 21/c'
_cod_database_code               1555514
_shelxl_version_number           2013-4