Synthesis of spiro[2.5]octa-4,7-dien-6-one with consecutive quaternary centers via 1,6-conjugate addition induced dearomatization of para-quinone methides.
Gai, Kuo; Fang, Xinxin; Li, Xuanyi; Xu, Jinyi; Wu, Xiaoming; Lin, Aijun; Yao, Hequan; Chemical communications (Cambridge, England) 51 (2015) 15831–15834; doi:10.1039/c5cc06287j

data_7118036
_publ_section_title
;
 Synthesis of spiro[2.5]octa-4,7-dien-6-one with consecutive quaternary
 centers via 1,6-conjugate addition induced dearomatization of
 para-quinone methides.
;
_journal_issue                   87
_journal_name_full               'Chemical communications (Cambridge, England)'
_journal_page_first              15831
_journal_page_last               15834
_journal_paper_doi               10.1039/c5cc06287j
_journal_volume                  51
_journal_year                    2015
_chemical_formula_sum            'C28 H37 Cl O5'
_chemical_formula_weight         489.03
_chemical_name_systematic
'diethyl 2-(chloro(phenyl)methyl)-2-(3,5-di-tert-butyl-4-hydroxyphenyl)malonate'
_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_block_doi                 10.5517/cc1jh5hp
_audit_creation_method           SHELXL-97
_audit_update_record
;
2015-07-23 deposited with the CCDC.
2015-09-04 downloaded from the CCDC.
;
_cell_angle_alpha                90.00
_cell_angle_beta                 105.460(5)
_cell_angle_gamma                90.00
_cell_formula_units_Z            4
_cell_length_a                   13.459(4)
_cell_length_b                   10.509(3)
_cell_length_c                   20.134(6)
_cell_measurement_reflns_used    3191
_cell_measurement_temperature    296(2)
_cell_measurement_theta_max      22.48
_cell_measurement_theta_min      2.49
_cell_volume                     2744.7(14)
_computing_structure_refinement  'SHELXL-97 (Sheldrick, 2008)'
_computing_structure_solution    'SHELXS-97 (Sheldrick, 2008)'
_diffrn_ambient_temperature      296(2)
_diffrn_measured_fraction_theta_full 0.998
_diffrn_measured_fraction_theta_max 0.998
_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  0.0418
_diffrn_reflns_av_sigmaI/netI    0.0474
_diffrn_reflns_limit_h_max       15
_diffrn_reflns_limit_h_min       -16
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -12
_diffrn_reflns_limit_l_max       23
_diffrn_reflns_limit_l_min       -22
_diffrn_reflns_number            14824
_diffrn_reflns_theta_full        25.01
_diffrn_reflns_theta_max         25.01
_diffrn_reflns_theta_min         2.20
_exptl_absorpt_coefficient_mu    0.173
_exptl_absorpt_correction_T_max  0.9674
_exptl_absorpt_correction_T_min  0.9588
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   sadabs
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.183
_exptl_crystal_density_method    'not measured'
_exptl_crystal_description       block
_exptl_crystal_F_000             1048
_exptl_crystal_recrystallization_method
'Re-crystallisation from solvent: Hexane/DCM'
_exptl_crystal_size_max          0.28
_exptl_crystal_size_mid          0.26
_exptl_crystal_size_min          0.22
_refine_diff_density_max         0.525
_refine_diff_density_min         -0.311
_refine_diff_density_rms         0.043
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.146
_refine_ls_hydrogen_treatment    mixed
_refine_ls_matrix_type           full
_refine_ls_number_parameters     316
_refine_ls_number_reflns         4833
_refine_ls_number_restraints     0
_refine_ls_restrained_S_all      1.146
_refine_ls_R_factor_all          0.0751
_refine_ls_R_factor_gt           0.0499
_refine_ls_shift/su_max          0.003
_refine_ls_shift/su_mean         0.000
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'calc w=1/[\s^2^(Fo^2^)+(0.0656P)^2^+0.4051P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_gt          0.1324
_refine_ls_wR_factor_ref         0.1476
_reflns_number_gt                3431
_reflns_number_total             4833
_reflns_threshold_expression     >2sigma(I)
_cod_data_source_file            c5cc06287j2.cif
_cod_data_source_block           20150715laj_0m
_cod_depositor_comments
;
The following automatic conversions were performed:

'_symmetry_cell_setting' value 'Monoclinic' changed to 'monoclinic'
according to
/usr/data/users/saulius/crontab/automatic-downloads/current/RSC/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 3271 2015-04-21 07:52:19Z andrius 
;
_cod_original_cell_volume        2744.8(13)
_cod_original_sg_symbol_H-M      'P2(1)/c  '
_cod_database_code               7118036