A new and efficient method for o-quinone methide intermediate generation: application to the biomimetic synthesis of the benzopyran derived natural products (+/-)-lucidene and (+/-)-alboatrin.
Rodriguez, Raphaël; Moses, John E.; Adlington, Robert M.; Baldwin, Jack E.; Organic & biomolecular chemistry 3 (2005) 3488–3495; doi:10.1039/b508972g

data_7150270
_publ_section_title
;
 A new and efficient method for o-quinone methide intermediate
 generation: application to the biomimetic synthesis of the benzopyran
 derived natural products (+/-)-lucidene and (+/-)-alboatrin.
;
_journal_issue                   19
_journal_name_full               'Organic &amp; biomolecular chemistry'
_journal_page_first              3488
_journal_page_last               3495
_journal_paper_doi               10.1039/b508972g
_journal_volume                  3
_journal_year                    2005
_chemical_compound_source
;
synthesis as described
;
_chemical_formula_moiety         ' C23 H32 O2 '
_chemical_formula_sum            'C23 H32 O2'
_chemical_formula_weight         340.51
_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
_cell_angle_alpha                90
_cell_angle_beta                 94.5151(8)
_cell_angle_gamma                90
_cell_formula_units_Z            8
_cell_length_a                   19.4765(3)
_cell_length_b                   9.6966(2)
_cell_length_c                   21.0587(4)
_cell_measurement_reflns_used    32823
_cell_measurement_temperature    150
_cell_measurement_theta_max      28
_cell_measurement_theta_min      5
_cell_volume                     3964.72(13)
_computing_cell_refinement
;
KappaCCD software 'DENZO' (Otwinowski & Minor, 1996)
;
_computing_data_collection
;
KappaCCD software 'Collect' (Nonius, 2000)
;
_computing_data_reduction
;
KappaCCD software 'DENZO' (Otwinowski & Minor, 1996)
;
_computing_publication_material
;
CRYSTALS (Watkin et al, 2001)
;
_computing_structure_refinement
;
CRYSTALS (Watkin et al, 2001)
;
_computing_structure_solution    'SIR92 (Giacovazzo et al, 1992)'
_diffrn_ambient_temperature      150
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_diffrn_measurement_device_type
;
Nonius KappaCCD
;
_diffrn_measurement_method       \w
_diffrn_radiation_monochromator  graphite
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71073
_diffrn_reflns_av_R_equivalents  0.051
_diffrn_reflns_limit_h_max       25
_diffrn_reflns_limit_h_min       -25
_diffrn_reflns_limit_k_max       12
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       27
_diffrn_reflns_limit_l_min       -27
_diffrn_reflns_number            32823
_diffrn_reflns_theta_full        27.466
_diffrn_reflns_theta_max         27.466
_diffrn_reflns_theta_min         5.116
_diffrn_standards_decay_%        0.00
_diffrn_standards_interval_count 0
_diffrn_standards_interval_time  0
_diffrn_standards_number         0
_exptl_absorpt_coefficient_mu    0.071
_exptl_absorpt_correction_T_max  0.99
_exptl_absorpt_correction_T_min  0.98
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details
;
Denzo/Scalepack (Otwinowski & Minor, 1996)
;
_exptl_crystal_colour            ' colourless '
_exptl_crystal_density_diffrn    1.141
_exptl_crystal_description       ' plate '
_exptl_crystal_F_000             1488
_exptl_crystal_size_max          0.22
_exptl_crystal_size_mid          0.22
_exptl_crystal_size_min          0.08
_refine_diff_density_max         0.28
_refine_diff_density_min         -0.33
_refine_ls_extinction_method     None
_refine_ls_goodness_of_fit_ref   1.1038
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     464
_refine_ls_number_reflns         5437
_refine_ls_number_restraints     4
_refine_ls_R_factor_all          0.0853
_refine_ls_R_factor_gt           0.0432
_refine_ls_shift/su_max          0.007881
_refine_ls_structure_factor_coef F
_refine_ls_weighting_details
;
Method, part 1, Chebychev polynomial, (Watkin, 1994, Prince, 1982)
[weight] = 1.0/[A~0~*T~0~(x)+A~1~*T~1~(x) ... +A~n-1~]*T~n-1~(x)]
where A~i~ are the Chebychev coefficients listed below and x= Fcalc/Fmax
Method = Robust Weighting (Prince, 1982)
W = [weight] * [1-(deltaF/6*sigmaF)^2^]^2^
A~i~ are:
0.975 0.696 0.640
;
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_all         0.0695
_refine_ls_wR_factor_gt          0.0524
_refine_ls_wR_factor_ref         0.0524
_reflns_limit_h_max              25
_reflns_limit_h_min              -25
_reflns_limit_k_max              12
_reflns_limit_k_min              0
_reflns_limit_l_max              27
_reflns_limit_l_min              0
_reflns_number_gt                5437
_reflns_number_total             9000
_reflns_threshold_expression     I>3.00u(I)
_cod_data_source_file            b508972g.txt
_cod_data_source_block           arc793
_cod_depositor_comments
;
The following automatic conversions were performed:
'_atom_site_refinement_disorder_group' tag replaced with
'_atom_site_disorder_group'.

Automatic conversion script
Id: cif_correct_tags 1383 2010-08-28 14:59:44Z saulius 

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 
;
_cod_original_sg_symbol_H-M      'P 1 21/c 1 '
_cod_original_formula_sum        ' C23 H32 O2 '
_cod_database_code               7150270