Catalytic enantioselective total syntheses of bakkenolides I, J, and S: application of a carbene-catalyzed desymmetrization.
Phillips, Eric M.; Roberts, John M.; Scheidt, Karl A.; Organic letters 12 (2010) 2830–2833; doi:10.1021/ol100938j

data_1503020
_publ_section_title
;
 Catalytic enantioselective total syntheses of bakkenolides I, J, and S:
 application of a carbene-catalyzed desymmetrization.
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_journal_issue                   12
_journal_name_full               'Organic letters'
_journal_page_first              2830
_journal_page_last               2833
_journal_paper_doi               10.1021/ol100938j
_journal_volume                  12
_journal_year                    2010
_chemical_formula_sum            'C15 H22 O3'
_chemical_formula_weight         250.33
_chemical_name_common
(1'R,2'S,3a'R,4'S,7a'S)-1'-hydroxy-3a',4'-dimethyl-4-methylenedecahydro-2H-spiro[furan-3,2'-inden]-2-one
_space_group_IT_number           19
_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
_audit_update_record
;
2009-09-11 # Formatted by publCIF
;
_cell_angle_alpha                90.00
_cell_angle_beta                 90.00
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   7.33740(10)
_cell_length_b                   7.47950(10)
_cell_length_c                   25.3435(5)
_cell_measurement_temperature    100(2)
_cell_volume                     1390.85(4)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 1997)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 1990)'
_diffrn_ambient_temperature      100(2)
_diffrn_measured_fraction_theta_full 0.995
_diffrn_measured_fraction_theta_max 0.995
_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  0.0587
_diffrn_reflns_av_sigmaI/netI    0.0266
_diffrn_reflns_limit_h_max       9
_diffrn_reflns_limit_h_min       -10
_diffrn_reflns_limit_k_max       10
_diffrn_reflns_limit_k_min       -10
_diffrn_reflns_limit_l_max       35
_diffrn_reflns_limit_l_min       -35
_diffrn_reflns_number            30953
_diffrn_reflns_theta_full        30.17
_diffrn_reflns_theta_max         30.17
_diffrn_reflns_theta_min         1.61
_exptl_absorpt_coefficient_mu    0.082
_exptl_absorpt_correction_T_max  0.9840
_exptl_absorpt_correction_T_min  0.9499
_exptl_crystal_density_diffrn    1.195
_exptl_crystal_density_method    'not measured'
_exptl_crystal_F_000             544
_exptl_crystal_size_max          0.64
_exptl_crystal_size_mid          0.34
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.387
_refine_diff_density_min         -0.314
_refine_diff_density_rms         0.142
_refine_ls_abs_structure_details 'Flack H D (1983), Acta Cryst. A39, 876-881'
_refine_ls_abs_structure_Flack   -0.4(7)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.068
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     166
_refine_ls_number_reflns         4107
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.068
_refine_ls_R_factor_all          0.0412
_refine_ls_R_factor_gt           0.0361
_refine_ls_shift/su_max          0.002
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0544P)^2^+0.1934P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0946
_refine_ls_wR_factor_ref         0.0975
_reflns_number_gt                3858
_reflns_number_total             4107
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol100938j_si_001.cif
_cod_data_source_block           n0146_0m
_cod_database_code               1503020