Discovery of a Phosphine-Mediated Cycloisomerization of Alkynyl Hemiketals: Access to Spiroketals and Dihydropyrazoles via Tandem Reactions
Jaideep Saha; Chris Lorenc; Bikash Surana; Mark W. Peczuh; Journal of Organic Chemistry 77 (2012) 3846–3858; doi:10.1021/jo3001854

data_4027155
_publ_section_title
;
 Discovery of a Phosphine-Mediated Cycloisomerization of Alkynyl
 Hemiketals: Access to Spiroketals and Dihydropyrazoles via Tandem
 Reactions
;
_journal_name_full               'Journal of Organic Chemistry'
_journal_page_first              3846
_journal_page_last               3858
_journal_paper_doi               10.1021/jo3001854
_journal_volume                  77
_journal_year                    2012
_chemical_absolute_configuration unk
_chemical_formula_moiety         'C18 H24 O8 '
_chemical_formula_sum            'C18 H24 O8'
_chemical_formula_weight         368.38
_space_group_IT_number           19
_symmetry_cell_setting           orthorhombic
_symmetry_Int_Tables_number      19
_symmetry_space_group_name_Hall  'P 2ac 2ab'
_symmetry_space_group_name_H-M   'P 21 21 21'
_cell_angle_alpha                90.0000
_cell_angle_beta                 90.0000
_cell_angle_gamma                90.0000
_cell_formula_units_Z            8
_cell_length_a                   10.150(6)
_cell_length_b                   13.718(8)
_cell_length_c                   26.178(15)
_cell_measurement_reflns_used    5528
_cell_measurement_temperature    223.1
_cell_measurement_theta_max      27.5
_cell_measurement_theta_min      3.1
_cell_volume                     3645(4)
_computing_cell_refinement       PROCESS-AUTO
_computing_data_collection       PROCESS-AUTO
_computing_data_reduction        CrystalStructure
_computing_publication_material  'CrystalStructure 3.8'
_computing_structure_refinement  SHELXL
_computing_structure_solution    SHELXS97
_diffrn_detector_area_resol_mean 6.85
_diffrn_measured_fraction_theta_full 0.964
_diffrn_measured_fraction_theta_max 0.964
_diffrn_measurement_device_type  'Rigaku SCXmini'
_diffrn_measurement_method       \w
_diffrn_radiation_type           'Mo K\a'
_diffrn_radiation_wavelength     0.71075
_diffrn_reflns_av_R_equivalents  0.055
_diffrn_reflns_limit_h_max       12
_diffrn_reflns_limit_h_min       -12
_diffrn_reflns_limit_k_max       8
_diffrn_reflns_limit_k_min       -17
_diffrn_reflns_limit_l_max       29
_diffrn_reflns_limit_l_min       -33
_diffrn_reflns_number            11526
_diffrn_reflns_theta_full        27.48
_diffrn_reflns_theta_max         27.48
_exptl_absorpt_coefficient_mu    0.106
_exptl_absorpt_correction_T_max  0.979
_exptl_absorpt_correction_T_min  0.575
_exptl_absorpt_correction_type   multi-scan
_exptl_absorpt_process_details   'Jacobson, R. (1998) Private communication'
_exptl_crystal_colour            colorless
_exptl_crystal_density_diffrn    1.343
_exptl_crystal_description       block
_exptl_crystal_F_000             1568.00
_exptl_crystal_size_max          0.30
_exptl_crystal_size_mid          0.30
_exptl_crystal_size_min          0.20
_refine_diff_density_max         0.24
_refine_diff_density_min         -0.28
_refine_ls_abs_structure_details
'Flack, H. D. (1983), Acta Cryst. A39, 876-881.  3159 Friedel Pairs'
_refine_ls_abs_structure_Flack   0.1(13)
_refine_ls_extinction_method     none
_refine_ls_goodness_of_fit_ref   1.062
_refine_ls_hydrogen_treatment    refall
_refine_ls_number_parameters     470
_refine_ls_number_reflns         7655
_refine_ls_R_factor_gt           0.0765
_refine_ls_shift/su_max          0.0010
_refine_ls_structure_factor_coef Fsqd
_refine_ls_weighting_details
'w = 1/[\s^2^(Fo^2^)+(0.0747P)^2^+0.5392P] where P=(Fo^2^+2Fc^2^)/3'
_refine_ls_weighting_scheme      calc
_refine_ls_wR_factor_ref         0.1871
_reflns_number_gt                5107
_reflns_number_total             7655
_reflns_threshold_expression     F^2^>2.0\s(F^2^)
_cod_data_source_file            jo3001854_si_001.cif
_cod_data_source_block           '_UCONN_MP10'
_cod_original_formula_sum        'C18 H24 O8 '
_cod_database_code               4027155