Asymmetric Synthesis, Structure, and Reactivity of Unexpectedly Stable Spiroepoxy-β-Lactones Including Facile Conversion to Tetronic Acids: Application to (+)-Maculalactone A
Richard J. Duffy; Kay A. Morris; Ravikrishna Vallakati; Wei Zhang; Daniel Romo; Journal of Organic Chemistry 74 (2009) 4772–4781; doi:10.1021/jo900499e

data_4024626
_publ_section_title
;
Asymmetric Synthesis, Structure, and Reactivity of Unexpectedly Stable
Spiroepoxy-\b-Lactones Including Facile Conversion to Tetronic Acids:
Application to (+)-Maculalactone A
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              4772
_journal_page_last               4781
_journal_paper_doi               10.1021/jo900499e
_journal_volume                  74
_journal_year                    2009
_chemical_formula_sum            'C18 H28 O3'
_chemical_formula_weight         292.40
_space_group_IT_number           14
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-P 2ybc'
_symmetry_space_group_name_H-M   'P 1 21/c 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                 95.406(13)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   14.447(3)
_cell_length_b                   9.549(2)
_cell_length_c                   12.138(3)
_cell_measurement_reflns_used    654
_cell_measurement_temperature    110(2)
_cell_measurement_theta_max      47.01
_cell_measurement_theta_min      3.07
_cell_volume                     1667.1(7)
_computing_cell_refinement       'Bruker FRAMBO'
_computing_data_collection       'Bruker FRAMBO'
_computing_data_reduction        'Bruker SAINT'
_computing_molecular_graphics    'Bruker SHELXTL'
_computing_publication_material  'Bruker SHELXTL'
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      110(2)
_diffrn_measured_fraction_theta_full 0.872
_diffrn_measured_fraction_theta_max 0.872
_diffrn_measurement_device_type  'MWPC area detector'
_diffrn_measurement_method       'phi and omega scans'
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_source         'normal-focus sealed tube'
_diffrn_radiation_type           CuK\a
_diffrn_radiation_wavelength     1.54178
_diffrn_reflns_av_R_equivalents  0.0815
_diffrn_reflns_av_sigmaI/netI    0.0918
_diffrn_reflns_limit_h_max       16
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       9
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       13
_diffrn_reflns_limit_l_min       -13
_diffrn_reflns_number            10030
_diffrn_reflns_theta_full        59.99
_diffrn_reflns_theta_max         59.99
_diffrn_reflns_theta_min         5.91
_exptl_absorpt_coefficient_mu    0.611
_exptl_absorpt_correction_T_max  0.9939
_exptl_absorpt_correction_T_min  0.9414
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.165
_exptl_crystal_density_meas      0
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       needle
_exptl_crystal_F_000             640
_exptl_crystal_size_max          0.10
_exptl_crystal_size_mid          0.01
_exptl_crystal_size_min          0.01
_refine_diff_density_max         0.409
_refine_diff_density_min         -0.255
_refine_diff_density_rms         0.067
_refine_ls_extinction_coef       0.0023(6)
_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   1.034
_refine_ls_hydrogen_treatment    riding
_refine_ls_matrix_type           full
_refine_ls_number_parameters     192
_refine_ls_number_reflns         2161
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.034
_refine_ls_R_factor_all          0.1106
_refine_ls_R_factor_gt           0.0822
_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^)+(0.0473P)^2^+5.5194P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1805
_refine_ls_wR_factor_ref         0.1973
_reflns_number_gt                1550
_reflns_number_total             2161
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            jo900499e_si_002.cif
_cod_data_source_block           dr35a
_cod_depositor_comments
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The following automatic conversions were performed:
'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to '/home/saulius/struct/CIF-dictionaries/cif_core.dic'
dictionary named 'cif_core.dic' version 2.4.1 from 2010-06-29.

Automatic conversion script
Id: cif_fix_enum 1527 2010-12-29 10:47:43Z saulius 
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_cod_original_sg_symbol_H-M      P2(1)/c
_cod_database_code               4024626