Total synthesis and structural elucidation of ent-micropyrone and (+)-ascosalipyrone.
Gregg, Claire; Perkins, Michael V.; Organic & biomolecular chemistry 10 (2012) 6547–6553; doi:10.1039/c2ob25501d

data_7152498
_publ_section_title
;
 Total synthesis and structural elucidation of ent-micropyrone and
 (+)-ascosalipyrone.
;
_journal_issue                   32
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              6547
_journal_page_last               6553
_journal_paper_doi               10.1039/c2ob25501d
_journal_volume                  10
_journal_year                    2012
_chemical_absolute_configuration syn
_chemical_formula_sum            'C14 H20 O4'
_chemical_formula_weight         252.30
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_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                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   8.1642(3)
_cell_length_b                   12.0184(5)
_cell_length_c                   14.2772(5)
_cell_measurement_reflns_used    5417
_cell_measurement_temperature    150(2)
_cell_measurement_theta_max      29.8536
_cell_measurement_theta_min      2.2106
_cell_volume                     1400.89(9)
_computing_cell_refinement
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET)
(compiled Jan 5 2010,16:28:46)
;
_computing_data_collection
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET)
(compiled Jan 5 2010,16:28:46)
;
_computing_data_reduction
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET)
(compiled Jan 5 2010,16:28:46)
;
_computing_molecular_graphics    'X-Seed (Barbour, 2003)'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      150(2)
_diffrn_detector_area_resol_mean 16.2413
_diffrn_measured_fraction_theta_full 1.000
_diffrn_measured_fraction_theta_max 0.924
_diffrn_measurement_device_type  'Xcalibur, Eos'
_diffrn_measurement_method       '\w scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'Enhance (Mo) X-ray Source'
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.7107
_diffrn_reflns_av_R_equivalents  0.0219
_diffrn_reflns_av_sigmaI/netI    0.0393
_diffrn_reflns_limit_h_max       11
_diffrn_reflns_limit_h_min       -11
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -15
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -19
_diffrn_reflns_number            10454
_diffrn_reflns_theta_full        26.00
_diffrn_reflns_theta_max         29.92
_diffrn_reflns_theta_min         2.22
_exptl_absorpt_coefficient_mu    0.087
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.98666
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
CrysAlisPro, Oxford Diffraction Ltd.,
Version 1.171.33.55 (release 05-01-2010 CrysAlis171 .NET)
(compiled Jan 5 2010,16:28:46)
Empirical absorption correction using spherical harmonics,
implemented in SCALE3 ABSPACK scaling algorithm.
;
_exptl_crystal_colour            colourless
_exptl_crystal_density_diffrn    1.196
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             544
_exptl_crystal_size_max          0.26
_exptl_crystal_size_mid          0.13
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.216
_refine_diff_density_min         -0.198
_refine_diff_density_rms         0.038
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   0.9(8)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   0.973
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     169
_refine_ls_number_reflns         3600
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.973
_refine_ls_R_factor_all          0.0487
_refine_ls_R_factor_gt           0.0374
_refine_ls_shift/su_max          0.001
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0567P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0907
_refine_ls_wR_factor_ref         0.0935
_reflns_number_gt                2916
_reflns_number_total             3600
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c2ob25501d.txt
_cod_data_source_block           g:\cg7157~1\cg71572
_cod_original_sg_symbol_H-M      P212121
_cod_database_code               7152498