N-heterocyclic carbene catalyzed annulation of enals to aurone analogs: synthesis of cyclopentene-fused spirobenzofuran-3-ones.
Seetha Lakshmi, K. C.; Krishnan, Jagadeesh; Sinu, C. R.; Varughese, Sunil; Nair, Vijay; Organic letters 16 (2014) 6374–6377; doi:10.1021/ol5031684

data_1518430
_publ_section_title
;
 N-heterocyclic carbene catalyzed annulation of enals to aurone analogs:
 synthesis of cyclopentene-fused spirobenzofuran-3-ones.
;
_journal_issue                   24
_journal_name_full               'Organic letters'
_journal_page_first              6374
_journal_page_last               6377
_journal_paper_doi               10.1021/ol5031684
_journal_volume                  16
_journal_year                    2014
_chemical_formula_moiety         'C27 H24 O3'
_chemical_formula_sum            'C27 H24 O3'
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_space_group_name_H-M_alt        'P b c a'
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_computing_cell_refinement
;
CrystalClear-SM Expert 2.0 r14k (Rigaku, 2012)
;
_computing_data_collection
;
CrystalClear-SM Expert 2.0 r14k (Rigaku, 2012)
;
_computing_data_reduction
;
CrystalClear-SM Expert 2.0 r14k (Rigaku, 2012)
;
_computing_structure_refinement  'SHELXL-2013 (Sheldrick, 2013)'
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_diffrn_measurement_device_type
;
Rigaku Saturn724+ (4x4 bin mode)
;
_diffrn_measurement_method       'profile data from \w-scans'
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_diffrn_reflns_limit_l_max       21
_diffrn_reflns_limit_l_min       -18
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_exptl_absorpt_coefficient_mu    0.079
_exptl_absorpt_correction_T_max  1.000
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_exptl_absorpt_correction_type   empirical
_exptl_absorpt_process_details   'Jacobson, unpublished results'
_exptl_crystal_colour            Colorless
_exptl_crystal_density_diffrn    1.223
_exptl_crystal_description       Block
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_exptl_crystal_size_min          0.600
_refine_diff_density_max         0.225
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_refine_ls_extinction_method     none
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_refine_ls_shift/su_max          0.000
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w=1/[\s^2^(Fo^2^)+(0.1088P)^2^] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1669
_refine_ls_wR_factor_ref         0.1994
_reflns_Friedel_coverage         0.000
_reflns_number_gt                2462
_reflns_number_total             4322
_reflns_threshold_expression     'I > 2\s(I)'
_cod_data_source_file            ol5031684_si_002.cif
_cod_data_source_block           shelx
_cod_depositor_comments
;
The following automatic conversions were performed:

'_exptl_absorpt_correction_type' value 'Empirical' changed to
'empirical' according to
/home/saulius/struct/COD-crude-data--automatic-downloads/rss-feeds/ACS/lib/dictionaries/cif_core.dic
dictionary named 'cif_core.dic' version 2.4.2 from 2011-04-26.

Automatic conversion script
Id: cif_fix_values 2935 2014-11-11 08:27:57Z andrius 

 Adding full bibliography for 1518430.cif.
;
_cod_database_code               1518430
_shelx_estimated_absorpt_t_min   0.954
_shelx_estimated_absorpt_t_max   0.954
_shelxl_version_number           2013-4
_shelx_res_checksum              61296
_shelx_hkl_checksum              58034