Synthesis of the [5-7-6] tricyclic core of guanacastepene A via an intramolecular Mukaiyama aldol reaction.
Du, Xiaohui; Chu, Hiufung V.; Kwon, Ohyun; Organic letters 5 (2003) 1923–1926; doi:10.1021/ol0344873

data_1507312
_publ_section_title
;
 Synthesis of the [5-7-6] tricyclic core of guanacastepene A via an
 intramolecular Mukaiyama aldol reaction.
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_journal_issue                   11
_journal_name_full               'Organic letters'
_journal_page_first              1923
_journal_page_last               1926
_journal_paper_doi               10.1021/ol0344873
_journal_volume                  5
_journal_year                    2003
_chemical_formula_sum            'C18 H28 O4'
_chemical_formula_weight         308.40
_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                 94.5070(10)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   5.9749(4)
_cell_length_b                   9.9112(6)
_cell_length_c                   27.8315(18)
_cell_measurement_reflns_used    3479
_cell_measurement_temperature    100(2)
_cell_measurement_theta_max      28.14
_cell_measurement_theta_min      2.56
_cell_volume                     1643.04(18)
_computing_cell_refinement       'Bruker SMART'
_computing_data_collection       'Bruker SMART'
_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      100(2)
_diffrn_measured_fraction_theta_full 0.965
_diffrn_measured_fraction_theta_max 0.965
_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  0.0200
_diffrn_reflns_av_sigmaI/netI    0.0231
_diffrn_reflns_limit_h_max       6
_diffrn_reflns_limit_h_min       -7
_diffrn_reflns_limit_k_max       11
_diffrn_reflns_limit_k_min       -13
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -36
_diffrn_reflns_number            10494
_diffrn_reflns_theta_full        28.31
_diffrn_reflns_theta_max         28.31
_diffrn_reflns_theta_min         2.18
_diffrn_standards_decay_%        0
_exptl_absorpt_coefficient_mu    0.086
_exptl_absorpt_correction_T_max  0.9829
_exptl_absorpt_correction_T_min  0.9746
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Sadabs (Bruker)'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.247
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             672
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.20
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.332
_refine_diff_density_min         -0.177
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.031
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     202
_refine_ls_number_reflns         3949
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.031
_refine_ls_R_factor_all          0.0458
_refine_ls_R_factor_gt           0.0368
_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^)+(0.0476P)^2^+0.5383P] where =P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.0921
_refine_ls_wR_factor_ref         0.0990
_reflns_number_gt                3331
_reflns_number_total             3949
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            ol0344873si20030321_125853.cif
_cod_data_source_block           compound21b
_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      P2(1)/c
_cod_database_code               1507312