A stereoselective synthetic route to 1,6-Dioxaspiro[4.4]non-3-en-2-ones from cyclopropyl alkyl ketones and alpha-ketoesters.
Yang, Yong-Hua; Shi, Min; Organic letters 8 (2006) 1709–1712; doi:10.1021/ol060415a

data_1505935
_publ_section_title
;
 A stereoselective synthetic route to 1,6-Dioxaspiro[4.4]non-3-en-2-ones
 from cyclopropyl alkyl ketones and alpha-ketoesters.
;
_journal_issue                   8
_journal_name_full               'Organic letters'
_journal_page_first              1709
_journal_page_last               1712
_journal_paper_doi               10.1021/ol060415a
_journal_volume                  8
_journal_year                    2006
_chemical_formula_sum            'C22 H22 O3'
_chemical_formula_weight         334.40
_space_group_IT_number           15
_symmetry_cell_setting           monoclinic
_symmetry_space_group_name_Hall  '-C 2yc'
_symmetry_space_group_name_H-M   'C 1 2/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                 101.178(2)
_cell_angle_gamma                90.00
_cell_formula_units_Z            8
_cell_length_a                   15.4115(17)
_cell_length_b                   15.2733(17)
_cell_length_c                   15.5755(18)
_cell_measurement_reflns_used    2820
_cell_measurement_temperature    293(2)
_cell_measurement_theta_max      46.548
_cell_measurement_theta_min      4.926
_cell_volume                     3596.7(7)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_computing_data_reduction        'Bruker SHELXTL'
_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      293(2)
_diffrn_measured_fraction_theta_full 0.994
_diffrn_measured_fraction_theta_max 0.994
_diffrn_measurement_device_type  'CCD area detector'
_diffrn_measurement_method       'phi and omega scans'
_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  0.1245
_diffrn_reflns_av_sigmaI/netI    0.0798
_diffrn_reflns_limit_h_max       19
_diffrn_reflns_limit_h_min       -19
_diffrn_reflns_limit_k_max       16
_diffrn_reflns_limit_k_min       -19
_diffrn_reflns_limit_l_max       19
_diffrn_reflns_limit_l_min       -18
_diffrn_reflns_number            10521
_diffrn_reflns_theta_full        27.00
_diffrn_reflns_theta_max         27.00
_diffrn_reflns_theta_min         1.90
_exptl_absorpt_coefficient_mu    0.081
_exptl_absorpt_correction_T_max  1.00000
_exptl_absorpt_correction_T_min  0.62969
_exptl_absorpt_correction_type   empirical
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.235
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             1424
_exptl_crystal_size_max          0.503
_exptl_crystal_size_mid          0.361
_exptl_crystal_size_min          0.160
_refine_diff_density_max         0.229
_refine_diff_density_min         -0.197
_refine_diff_density_rms         0.046
_refine_ls_extinction_coef       0.0021(4)
_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   0.902
_refine_ls_hydrogen_treatment    constr
_refine_ls_matrix_type           full
_refine_ls_number_parameters     228
_refine_ls_number_reflns         3908
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      0.902
_refine_ls_R_factor_all          0.0762
_refine_ls_R_factor_gt           0.0526
_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^)+(0.0694P)^2^+0.0000P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1355
_refine_ls_wR_factor_ref         0.1451
_reflns_number_gt                2395
_reflns_number_total             3908
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol060415asi20060216_073546.cif
_cod_data_source_block           cd25430
_cod_depositor_comments
;
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_values 1715 2011-07-08 13:25:40Z adriana 
;
_cod_original_sg_symbol_H-M      C2/c
_cod_database_code               1505935