supplementary materials


mw2079 scheme

Acta Cryst. (2012). E68, o2668-o2669    [ doi:10.1107/S1600536812034514 ]

Monoclinic polymorph of 2,5-dideoxy-2,5-epithio-1,3:4,6-bis-O-[(R)-phenylmethylene]-L-iditol

J. G. Gibson, J. Y. Cho, F. R. Fronczek and S. F. Watkins

Abstract top

The title compound C20H20O4S, is polymorphic. In the tetragonal form, the molecule lies on a crystallographic twofold axis, while the monoclinic form has only approximate C2 molecular symmetry. The greatest excursion from C2 symmetry is in the orientation of the two phenyl rings; at 100 K, one of the rings is rotated -37.2 (3)° and the other by 46.9 (3)° from their symmetric (tetragonal) positions. There are only minor differences in the three-ring nucleus; the best molecular fit of the tetragonal and monoclinic forms, both at 100 K and excluding phenyl rings and H atoms, shows an r.m.s. deviation of 0.066 Å. Both forms have the same absolute configuration.

Comment top

The tetragonal form of the title compound (I), C20H20O4S, was determined at 295 K (Rao et al., 1993, hereinafter P4295). We re-examined the tetragonal form at 100 K in our laboratory (hereinafter P4100) and determined the absolute configuration. These data are deposited at the Cambridge Crystallographic Data Centre (Allen, 2002), CCDC 851380 (Gibson et al., 2011). There is a 2.8% volume decrease upon lowering the temperature from 295 K to 100 K but the molecular symmetry is C2 at both temperatures and there is no significant change in molecular structure. The best molecular fit (Gould et al., 1988) of all non-H atoms in P4295 and P4100 yields δr.m.s. = 0.022 Å, while excluding the phenyl groups yields δr.m.s. = 0.011 Å.

In the monoclinic form at 100 K (P2100) the molecular symmetry is C1. The molecular volume of P2100 (435.2 (3) Å3/molecule) is greater than P4100 (433.6 (1) Å3/molecule). The thirteen non-H atoms of the three central rings in P2100 and P4100 are arranged similarly with best molecular fit δr.m.s. = 0.066 Å. The most pronounced structural difference between P2100 and P4100 is in the orientation of the phenyl rings. In P4100, two equivalent O—C—C—C torsions of -14.5 (3)° become +32.4 (2)° and -51.7 (2)° in P2100. The global minimum conformation of this molecule has been calculated using MM2 (Winn & Goodman, 2001) and confirmed by us (Cambridgesoft, 2010). Like the tetragonal form, the minimum conformation has C2 symmetry, but the two equivalent O—C—C—C torsions representing the orientation of the phenyl rings are -56°.

Based on the Flack parameter x = 0.02 (5) (Flack, 1983) and Hooft parameters y = 0.00 (3) and P2(true) = 1.000 for 2730 Bijvoet pairs (Hooft et al., 2008), the absolute configurations of the tetragonal and monoclinic forms are identical at 100 K, with stereochemical specification (2R,4aS,5aS,8R,9aS,9bS)-2,8-diphenylhexahydrothieno[3,2 - d:4,5 - d'] bis([1,3]dioxine).

Related literature top

For details of the synthesis, see: Rao et al. (1988). For the structure of the tetragonal form at 295 K (CCDC refcode WAMRAD), see: Rao et al. (1993); and at 100 K (CCDC refcode 851380), see: Gibson et al. (2011). For a preliminary report of the structures of both polymorphs at room temperature, see: Fronczek et al. (2002). For a description of the Cambridge Structural Database, see: Allen (2002). For the determination of the absolute configuration from Bijvoet pairs, see: Hooft et al. (2008); Flack (1983). For details of the ,olecular mechanics software used, see: Cambridgesoft (2010); Winn & Goodman (2001).

Experimental top

The title compound was prepared by Dr. Ronald Voll according to the scheme reported by Rao et al. (1988). A suitable single-crystal was obtained by recrystallization from ethanol.

Refinement top

All H atoms were placed in calculated positions, guided by difference maps, with C—H bond distances 0.95 (aromatic C), 0.99 (CH2), 1.00 Å, (R3CH) and Uiso=1.2Ueq, thereafter refined as riding. The absolute configuration, based on 2730 Bijvoet pairs with Flack parameter x = 0.02 (5), Hooft parameter y = 0.00 (3) and Hooft P2(true) = 1.000, is consistent with that of the starting materials.

Computing details top

Data collection: COLLECT (Nonius, 2000); cell refinement: DENZO and SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SHELXS86 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999) and IDEAL (Gould et al., 1988).

Figures top
[Figure 1] Fig. 1. View of (I) (50% probability displacement ellipsoids).
2,5-dideoxy-2,5-epithio-1,3:4,6-bis-O-[(R)-phenylmethylene]- L-iditol top
Crystal data top
C20H20O4SF(000) = 376
Mr = 356.42Dx = 1.36 Mg m3
Monoclinic, P21Melting point: 481.5(5) K
Hall symbol: P 2ybMo Kα radiation, λ = 0.71073 Å
a = 6.158 (1) ÅCell parameters from 3254 reflections
b = 9.223 (2) Åθ = 2.5–33.1°
c = 15.407 (4) ŵ = 0.21 mm1
β = 95.785 (8)°T = 100 K
V = 870.6 (3) Å3Lath, colorless
Z = 20.25 × 0.22 × 0.10 mm
Data collection top
Nonius KappaCCD
diffractometer
6225 independent reflections
Radiation source: sealed tube5648 reflections with I > 2σ(I)
Horizonally mounted graphite crystal monochromatorRint = 0
Detector resolution: 9 pixels mm-1θmax = 33.1°, θmin = 2.6°
ω and φ scansh = 99
Absorption correction: multi-scan
(SCALEPACK; Otwinowski & Minor, 1997)
k = 1413
Tmin = 0.950, Tmax = 0.980l = 023
6225 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.037H-atom parameters constrained
wR(F2) = 0.088 w = 1/[σ2(Fo2) + (0.0366P)2 + 0.1562P]
where P = (Fo2 + 2Fc2)/3
S = 1.05(Δ/σ)max = 0.001
6225 reflectionsΔρmax = 0.29 e Å3
227 parametersΔρmin = 0.23 e Å3
1 restraintAbsolute structure: Flack (1983), 2730 Bijvoet pairs
0 constraintsFlack parameter: 0.02 (5)
Primary atom site location: structure-invariant direct methods
Crystal data top
C20H20O4SV = 870.6 (3) Å3
Mr = 356.42Z = 2
Monoclinic, P21Mo Kα radiation
a = 6.158 (1) ŵ = 0.21 mm1
b = 9.223 (2) ÅT = 100 K
c = 15.407 (4) Å0.25 × 0.22 × 0.10 mm
β = 95.785 (8)°
Data collection top
Nonius KappaCCD
diffractometer
6225 independent reflections
Absorption correction: multi-scan
(SCALEPACK; Otwinowski & Minor, 1997)
5648 reflections with I > 2σ(I)
Tmin = 0.950, Tmax = 0.980Rint = 0
6225 measured reflectionsθmax = 33.1°
Refinement top
R[F2 > 2σ(F2)] = 0.037H-atom parameters constrained
wR(F2) = 0.088Δρmax = 0.29 e Å3
S = 1.05Δρmin = 0.23 e Å3
6225 reflectionsAbsolute structure: Flack (1983), 2730 Bijvoet pairs
227 parametersFlack parameter: 0.02 (5)
1 restraint
Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.7808 (2)0.62050 (15)0.17832 (8)0.0169 (2)
H10.72750.55540.12880.02*
C20.6502 (2)0.76146 (15)0.17125 (8)0.0163 (2)
H20.49150.74180.15540.02*
C30.7424 (2)0.85423 (15)0.10263 (8)0.0161 (2)
H30.6810.95460.10240.019*
C40.9911 (2)0.85639 (15)0.12534 (8)0.0168 (2)
H41.02760.92790.17340.02*
C51.1053 (2)0.90189 (16)0.04642 (9)0.0212 (3)
H5A1.0861.00750.03690.025*
H5B1.26360.88220.0580.025*
C60.7929 (2)0.84807 (15)0.04585 (8)0.0167 (2)
H60.76220.95460.04760.02*
C70.7107 (2)0.78161 (14)0.13235 (8)0.0172 (2)
C80.4961 (2)0.73435 (15)0.14903 (9)0.0198 (2)
H80.39990.73950.10470.024*
C90.4225 (2)0.67920 (18)0.23124 (8)0.0229 (2)
H90.27710.64450.24220.027*
C100.5608 (2)0.67481 (19)0.29699 (8)0.0259 (3)
H100.5090.63910.35310.031*
C110.7744 (3)0.72253 (17)0.28063 (9)0.0279 (3)
H110.86950.71920.32550.033*
C120.8496 (2)0.77535 (16)0.19836 (9)0.0232 (3)
H120.99640.80730.18720.028*
C130.7489 (2)0.54497 (15)0.26421 (8)0.0197 (2)
H13A0.59920.50490.26130.024*
H13B0.8530.46330.27330.024*
C140.6415 (2)0.76351 (14)0.32492 (8)0.0161 (2)
H140.48570.73130.32010.019*
C150.6900 (2)0.85965 (15)0.40299 (8)0.0168 (2)
C160.5382 (2)0.87628 (16)0.46339 (9)0.0204 (3)
H160.40120.82820.45470.025*
C170.5876 (3)0.96367 (17)0.53664 (9)0.0252 (3)
H170.48380.97560.57770.03*
C180.7877 (3)1.03315 (17)0.54964 (9)0.0255 (3)
H180.82161.09160.59990.031*
C190.9390 (2)1.01740 (18)0.48917 (9)0.0263 (3)
H191.07561.06580.49790.032*
C200.8902 (2)0.93077 (17)0.41595 (9)0.0225 (3)
H200.99370.920.37460.027*
O11.02017 (15)0.82585 (11)0.03065 (6)0.01980 (19)
O20.68339 (15)0.78354 (10)0.02114 (5)0.01686 (18)
O30.68371 (15)0.84402 (11)0.24980 (6)0.01752 (18)
O40.78222 (15)0.64292 (10)0.33617 (6)0.01824 (19)
S11.06220 (5)0.67372 (4)0.16652 (2)0.01900 (7)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0184 (6)0.0173 (6)0.0159 (5)0.0023 (4)0.0049 (4)0.0009 (4)
C20.0156 (6)0.0206 (6)0.0127 (5)0.0006 (4)0.0016 (4)0.0001 (4)
C30.0186 (5)0.0169 (6)0.0130 (5)0.0019 (5)0.0022 (4)0.0002 (4)
C40.0191 (5)0.0158 (6)0.0153 (5)0.0015 (5)0.0009 (4)0.0016 (4)
C50.0204 (6)0.0236 (7)0.0196 (6)0.0057 (5)0.0024 (5)0.0012 (5)
C60.0190 (5)0.0181 (6)0.0135 (5)0.0011 (5)0.0035 (4)0.0022 (4)
C70.0232 (6)0.0146 (6)0.0139 (5)0.0006 (5)0.0029 (4)0.0016 (4)
C80.0241 (6)0.0181 (6)0.0176 (5)0.0016 (5)0.0036 (5)0.0002 (5)
C90.0290 (6)0.0186 (6)0.0203 (5)0.0035 (6)0.0009 (5)0.0014 (5)
C100.0401 (7)0.0211 (6)0.0165 (5)0.0059 (7)0.0020 (5)0.0034 (6)
C110.0402 (8)0.0282 (8)0.0168 (6)0.0065 (6)0.0107 (5)0.0039 (5)
C120.0278 (7)0.0255 (7)0.0175 (6)0.0051 (5)0.0073 (5)0.0010 (5)
C130.0287 (7)0.0148 (6)0.0164 (5)0.0010 (5)0.0070 (5)0.0002 (4)
C140.0169 (5)0.0195 (6)0.0123 (5)0.0018 (4)0.0037 (4)0.0004 (4)
C150.0203 (6)0.0174 (6)0.0127 (5)0.0036 (5)0.0009 (4)0.0010 (4)
C160.0218 (6)0.0214 (7)0.0187 (6)0.0012 (5)0.0048 (5)0.0010 (5)
C170.0307 (7)0.0272 (8)0.0184 (6)0.0033 (6)0.0067 (5)0.0028 (5)
C180.0309 (7)0.0258 (7)0.0190 (6)0.0045 (6)0.0013 (5)0.0060 (5)
C190.0222 (7)0.0315 (8)0.0244 (7)0.0006 (6)0.0018 (5)0.0061 (6)
C200.0200 (6)0.0290 (7)0.0189 (6)0.0003 (5)0.0032 (5)0.0045 (5)
O10.0184 (4)0.0243 (5)0.0173 (4)0.0027 (4)0.0045 (3)0.0002 (3)
O20.0193 (4)0.0209 (5)0.0107 (4)0.0027 (3)0.0031 (3)0.0004 (3)
O30.0244 (5)0.0167 (4)0.0119 (4)0.0027 (4)0.0038 (3)0.0003 (3)
O40.0243 (4)0.0164 (5)0.0139 (4)0.0029 (3)0.0017 (3)0.0001 (3)
S10.01709 (13)0.01938 (15)0.02103 (13)0.00212 (12)0.00436 (10)0.00274 (12)
Geometric parameters (Å, º) top
C1—C131.5256 (18)C9—H90.95
C1—C21.5266 (19)C10—C111.386 (2)
C1—S11.8279 (13)C10—H100.95
C1—H11C11—C121.3928 (19)
C2—O31.4271 (15)C11—H110.95
C2—C31.5144 (18)C12—H120.95
C2—H21C13—O41.4287 (16)
C3—O21.4288 (15)C13—H13A0.99
C3—C41.5360 (18)C13—H13B0.99
C3—H31C14—O41.4100 (15)
C4—C51.5236 (19)C14—O31.4211 (15)
C4—S11.8376 (14)C14—C151.5000 (17)
C4—H41C14—H141
C5—O11.4322 (16)C15—C161.3925 (18)
C5—H5A0.99C15—C201.3928 (19)
C5—H5B0.99C16—C171.3952 (19)
C6—O11.4103 (16)C16—H160.95
C6—O21.4195 (15)C17—C181.386 (2)
C6—C71.5073 (18)C17—H170.95
C6—H61C18—C191.390 (2)
C7—C81.3907 (19)C18—H180.95
C7—C121.3945 (19)C19—C201.390 (2)
C8—C91.3974 (18)C19—H190.95
C8—H80.95C20—H200.95
C9—C101.3879 (19)
C13—C1—C2109.75 (11)C11—C10—C9119.92 (12)
C13—C1—S1114.52 (9)C11—C10—H10120
C2—C1—S1105.18 (9)C9—C10—H10120
C13—C1—H1109.1C10—C11—C12119.93 (13)
C2—C1—H1109.1C10—C11—H11120
S1—C1—H1109.1C12—C11—H11120
O3—C2—C3104.97 (10)C11—C12—C7120.40 (14)
O3—C2—C1111.34 (10)C11—C12—H12119.8
C3—C2—C1107.41 (11)C7—C12—H12119.8
O3—C2—H2111O4—C13—C1111.31 (11)
C3—C2—H2111O4—C13—H13A109.4
C1—C2—H2111C1—C13—H13A109.4
O2—C3—C2105.99 (10)O4—C13—H13B109.4
O2—C3—C4111.45 (10)C1—C13—H13B109.4
C2—C3—C4106.47 (10)H13A—C13—H13B108
O2—C3—H3110.9O4—C14—O3110.58 (10)
C2—C3—H3110.9O4—C14—C15107.30 (10)
C4—C3—H3110.9O3—C14—C15107.83 (11)
C5—C4—C3110.57 (10)O4—C14—H14110.4
C5—C4—S1114.52 (10)O3—C14—H14110.4
C3—C4—S1105.32 (9)C15—C14—H14110.4
C5—C4—H4108.8C16—C15—C20119.77 (12)
C3—C4—H4108.8C16—C15—C14120.53 (12)
S1—C4—H4108.8C20—C15—C14119.69 (12)
O1—C5—C4111.54 (11)C15—C16—C17119.85 (14)
O1—C5—H5A109.3C15—C16—H16120.1
C4—C5—H5A109.3C17—C16—H16120.1
O1—C5—H5B109.3C18—C17—C16120.16 (14)
C4—C5—H5B109.3C18—C17—H17119.9
H5A—C5—H5B108C16—C17—H17119.9
O1—C6—O2110.77 (10)C17—C18—C19120.07 (13)
O1—C6—C7109.08 (11)C17—C18—H18120
O2—C6—C7109.30 (11)C19—C18—H18120
O1—C6—H6109.2C18—C19—C20119.97 (14)
O2—C6—H6109.2C18—C19—H19120
C7—C6—H6109.2C20—C19—H19120
C8—C7—C12119.57 (12)C19—C20—C15120.17 (13)
C8—C7—C6121.27 (12)C19—C20—H20119.9
C12—C7—C6119.06 (12)C15—C20—H20119.9
C7—C8—C9119.79 (12)C6—O1—C5109.91 (10)
C7—C8—H8120.1C6—O2—C3110.49 (10)
C9—C8—H8120.1C14—O3—C2112.91 (10)
C10—C9—C8120.36 (13)C14—O4—C13111.41 (9)
C10—C9—H9119.8C1—S1—C494.89 (6)
C8—C9—H9119.8
C13—C1—C2—O347.28 (14)O3—C14—C15—C16129.50 (12)
S1—C1—C2—O376.39 (11)O4—C14—C15—C2067.48 (15)
C13—C1—C2—C3161.68 (10)O3—C14—C15—C2051.66 (15)
S1—C1—C2—C338.02 (11)C20—C15—C16—C170.2 (2)
O3—C2—C3—O2172.01 (9)C14—C15—C16—C17178.65 (12)
C1—C2—C3—O269.39 (12)C15—C16—C17—C180.4 (2)
O3—C2—C3—C469.21 (12)C16—C17—C18—C190.8 (2)
C1—C2—C3—C449.39 (13)C17—C18—C19—C200.6 (2)
O2—C3—C4—C545.85 (15)C18—C19—C20—C150.0 (2)
C2—C3—C4—C5160.99 (11)C16—C15—C20—C190.4 (2)
O2—C3—C4—S178.37 (11)C14—C15—C20—C19178.47 (13)
C2—C3—C4—S136.77 (11)O2—C6—O1—C566.02 (13)
C3—C4—C5—O146.70 (16)C7—C6—O1—C5173.64 (10)
S1—C4—C5—O172.07 (13)C4—C5—O1—C656.52 (14)
O1—C6—C7—C8153.67 (12)O1—C6—O2—C365.43 (13)
O2—C6—C7—C832.42 (17)C7—C6—O2—C3174.35 (10)
O1—C6—C7—C1230.07 (16)C2—C3—O2—C6170.15 (10)
O2—C6—C7—C12151.31 (12)C4—C3—O2—C654.71 (13)
C12—C7—C8—C90.9 (2)O4—C14—O3—C260.93 (13)
C6—C7—C8—C9177.15 (13)C15—C14—O3—C2177.96 (10)
C7—C8—C9—C101.7 (2)C3—C2—O3—C14169.74 (10)
C8—C9—C10—C111.4 (3)C1—C2—O3—C1453.83 (13)
C9—C10—C11—C120.3 (2)O3—C14—O4—C1362.23 (13)
C10—C11—C12—C70.5 (2)C15—C14—O4—C13179.58 (10)
C8—C7—C12—C110.2 (2)C1—C13—O4—C1457.33 (14)
C6—C7—C12—C11176.16 (13)C13—C1—S1—C4134.53 (10)
C2—C1—C13—O449.24 (15)C2—C1—S1—C413.96 (9)
S1—C1—C13—O468.77 (13)C5—C4—S1—C1134.60 (10)
O4—C14—C15—C16111.36 (13)C3—C4—S1—C112.90 (9)
Acknowledgements top

Purchase of the diffractometer was made possible by grant No. LEQSF(1999–2000)-ENH-TR-13, administered by the Louisiana Board of Regents. We thank Dr Ronald Voll for providing the sample.

references
References top

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