[ (IUCr) rac-(E,trans)-4-Bromo-10,10-di­methyl-9,11-dioxabi­cyclo­[6.3.0]undec-4-ene

organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2414-3146

rac-(E,trans)-4-Bromo-10,10-di­methyl-9,11-dioxabi­cyclo­[6.3.0]undec-4-ene

aJohannes Gutenberg University Mainz, Department of Chemistry, Duesbergweg 10-14, 55099 Mainz, Germany
*Correspondence e-mail: detert@uni-mainz.de

Edited by M. Bolte, Goethe-Universität Frankfurt, Germany (Received 24 September 2020; accepted 25 September 2020; online 30 September 2020)

In the title compound, a cyclo­octene ring in a twist-boat conformation and a dioxolane ring with a distorted envelope conformation are annulated in a trans configuration. Alternating strands of single enanti­omers build up the crystal. Within the strands, the mol­ecules are connected by weak C—H⋯O hydrogen bonds.

3D view (loading...)
[Scheme 3D1]
Chemical scheme
[Scheme 1]

Structure description

The title compound (Fig. 1[link]) crystallizes as a racemic mixture of R,R- and S,S-enanti­omers forming strands of identical enanti­omers along the b-axis direction (Fig. 2[link]). The mol­ecules in the strands are connected via weak C—H⋯O contacts (H7B⋯O9 2.586 Å). A center of inversion relates these mol­ecules with their enanti­omeric counterparts in the parallel strands. The eight-membered ring features a twist-boat conformation. It is annulated to a dioxolane ring in a distorted envelope conformation. Within this envelope, atoms C4, C5, O11, and C10 are essentially coplanar (r.m.s. deviation 0.017 Å) but O9 lies 0.477 (2) Å below the mean plane. The cyclo­octene part has two planar moieties: one is the olefinic part (C2—C1—C8—C7), the other one [planar within 0.034 (2) Å] is composed of the four methyl­ene groups (C3—C2—C7—C6); these planes subtend a dihedral angle of 69.3 (2)°. A trans-ethyl­ene bridge (C4,C5) connects the rings; atom C4 lies 0.357 (5) Å above the central plane of the cyclo­octene moiety while C5 is positioned 0.541 (5) Å below this plane.

[Figure 1]
Figure 1
Perspective view of the title compound. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2]
Figure 2
Partial packing diagram of the title compound, viewed along the a axis. H atoms not involved in C—H⋯O contacts are omitted.

Synthesis and crystallization

The title compound was prepared in two steps from 4-bromo-9-oxabi­cyclo­[6.1.0]non-4-ene (Mayer & Meier, 1989[Mayer, W. & Meier, H. (1989). Chem. Ber. 122, 509-517.]) via hydrolysis of the epoxide to the trans-diol in alkaline (pH 10) water/dioxane (1/4) [1H NMR: 6.02 (t, 1H), 3.58 (m, 2 H), 3.17 (s, 2 H, OH), 2.81 (ddd, 1 H), 2.58 (ddd, 1 H), 2.0–2.33 (m, 4 H), 1.58 (m, 12 H); IR: (KBr): 3320, 2918, 1635, 1450, 1430, 1040, 980) and cetalization with 2,2-di­meth­oxy­propane. Alternatively, it may be prepared, more conveniently, from 10,10-dimethyl-9,11-dioxabi­cyclo­[6.3.0]undec-4-ene (Golding et al., 1980[Golding, B. T., Sell, C. S. & Sellars, P. J. (1980). J. Chem. Soc. Perkin Trans. 2, pp. 961-970.]) via bromination (Takahashi et al., 2000[Takahashi, A., Aso, M., Tanaka, M. & Suemune, H. (2000). Tetrahedron, 56, 1999-2006.]) and de­hydro­bromination with 1,8-di­aza­bicyclo­[5.4.0]undec-7-ene (DBU). Procedure: DBU (6 ml) was added to 4,5-di­bromo-10,10-dimethyl-9,11-dioxabi­cyclo­[6.3.0]undec-4-ene (8.92 g, 0.026 mol) in toluene (20 ml) and the mixture was stirred for 72 h. After filtration, the organic layer was washed with water (3 × 20 ml), brine, and dried over MgSO4. The solvent was evaporated in vacuo and the residue purified by chromatography on silica (cyclo­hexa­ne/ethyl acetate 40/1) to give the title compound as a yellowish oil in 88% yield (5.98 g). Crystallization from ethanol solution yielded colorless crystals, m.p. 313 K.

Spectroscopic data: 1H NMR (CDCl3): 6.03 (t, J = 8.2 Hz, 1 H), 3.88 (m, 2 H), 2.76 (ddd, J = 15.1 Hz, J′ = 10.4 Hz, J′′ = 10.2 Hz), 1 H), 2.54 (ddd, J = 14.7 Hz, J = 6.6 Hz, J′′ = 3.9 Hz, 1 H), 2.30 (m, 1 H), 2.16 (m, 3H), 1.55 (m, 2H), 1.38 (s, 3H), 1.37 (s, 3H). 13C NMR: 130.6 (CH), 124.0 (C—Br), 107.7 (O—C—O), 80.7(C—O), 79.9 (C—O), 32.2, 32.0, 29.4, 26.8 (CH3), 24.7.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1[link].

Table 1
Experimental details

Crystal data
Chemical formula C11H17BrO2
Mr 261.15
Crystal system, space group Triclinic, P[\overline{1}]
Temperature (K) 120
a, b, c (Å) 7.5770 (6), 7.6838 (6), 10.2038 (8)
α, β, γ (°) 101.843 (6), 90.893 (6), 104.642 (6)
V3) 561.11 (8)
Z 2
Radiation type Mo Kα
μ (mm−1) 3.64
Crystal size (mm) 0.38 × 0.32 × 0.28
 
Data collection
Diffractometer Stoe IPDS 2T
Absorption correction Integration (X-RED32; Stoe & Cie, 2019[Stoe & Cie (2019). X-RED32 and X-AREA. Stoe & Cie, Darmstadt, Germany.])
Tmin, Tmax 0.195, 0.460
No. of measured, independent and observed [I > 2σ(I)] reflections 4770, 2631, 2481
Rint 0.018
(sin θ/λ)max−1) 0.658
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.034, 0.087, 1.15
No. of reflections 2631
No. of parameters 129
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.73, −0.47
Computer programs: X-AREA WinXpose, Recipe and Integrate (Stoe & Cie, 2019[Stoe & Cie (2019). X-RED32 and X-AREA. Stoe & Cie, Darmstadt, Germany.]), SIR2004 (Burla et al., 2005[Burla, M. C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De Caro, L., Giacovazzo, C., Polidori, G. & Spagna, R. (2005). J. Appl. Cryst. 38, 381-388.]), SHELXL2018/3 (Sheldrick, 2015[Sheldrick, G. M. (2015). Acta Cryst. C71, 3-8.]) and PLATON (Spek, 2020[Spek, A. L. (2020). Acta Cryst. E76, 1-11.]).

Structural data


Computing details top

Data collection: X-AREA WinXpose (Stoe & Cie, 2019); cell refinement: X-AREA Recipe (Stoe & Cie, 2019); data reduction: X-AREA Integrate (Stoe & Cie, 2019); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL2018/3 (Sheldrick, 2015); molecular graphics: PLATON (Spek, 2020).

rac-(E,trans)-4-Bromo-10,10-dimethyl-9,11-dioxabicyclo[6.3.0]undec-4-ene top
Crystal data top
C11H17BrO2F(000) = 268
Mr = 261.15Dx = 1.546 Mg m3
Triclinic, P1Melting point: 313 K
a = 7.5770 (6) ÅMo Kα radiation, λ = 0.71073 Å
b = 7.6838 (6) ÅCell parameters from 10380 reflections
c = 10.2038 (8) Åθ = 2.8–28.4°
α = 101.843 (6)°µ = 3.64 mm1
β = 90.893 (6)°T = 120 K
γ = 104.642 (6)°Block, colourless
V = 561.11 (8) Å30.38 × 0.32 × 0.28 mm
Z = 2
Data collection top
Stoe IPDS 2T
diffractometer
2631 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus2481 reflections with I > 2σ(I)
Detector resolution: 6.67 pixels mm-1Rint = 0.018
rotation method, ω scansθmax = 27.9°, θmin = 2.8°
Absorption correction: integration
(X-RED32; Stoe & Cie, 2019)
h = 99
Tmin = 0.195, Tmax = 0.460k = 910
4770 measured reflectionsl = 1313
Refinement top
Refinement on F2Primary atom site location: dual
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.034H-atom parameters constrained
wR(F2) = 0.087 w = 1/[σ2(Fo2) + (0.0141P)2 + 2.0148P]
where P = (Fo2 + 2Fc2)/3
S = 1.15(Δ/σ)max < 0.001
2631 reflectionsΔρmax = 0.73 e Å3
129 parametersΔρmin = 0.47 e Å3
0 restraints
Special details top

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

Refinement. Hydrogen atoms were placed at calculated positions and were refined in the riding-model approximation with C–H ranging from 0.95 Å to 1.00 Å, and with Uiso(H) = 1.5 Ueq(Cmethyl) or Uiso(H) = 1.2 Ueq(C) for the remaining H atoms.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Br10.69071 (4)0.73859 (5)0.45594 (3)0.02384 (10)
C10.5268 (4)0.7199 (4)0.3056 (3)0.0190 (6)
C20.5275 (4)0.5685 (4)0.1873 (3)0.0213 (6)
H2A0.6531080.5533700.1796000.026*
H2B0.4915530.6034260.1046210.026*
C30.3971 (4)0.3848 (4)0.1982 (3)0.0202 (6)
H3A0.3830500.2979300.1100690.024*
H3B0.4534600.3327060.2639670.024*
C40.2085 (4)0.3970 (4)0.2404 (3)0.0186 (6)
H40.2175650.4620690.3367470.022*
C50.0995 (4)0.4826 (4)0.1559 (3)0.0191 (6)
H50.1438660.4702800.0635090.023*
C60.0962 (4)0.6811 (4)0.2095 (3)0.0216 (6)
H6A0.0595980.6936290.3029840.026*
H6B0.0012620.7089810.1556010.026*
C70.2785 (4)0.8259 (4)0.2082 (3)0.0243 (7)
H7A0.3291990.7979940.1197930.029*
H7B0.2547890.9488430.2193500.029*
C80.4184 (4)0.8321 (4)0.3168 (3)0.0219 (6)
H80.4293590.9217760.3980460.026*
O90.0976 (3)0.2121 (3)0.2245 (2)0.0214 (5)
C100.0876 (4)0.2202 (4)0.2147 (3)0.0208 (6)
O110.0850 (3)0.3686 (3)0.1490 (3)0.0252 (5)
C120.1986 (4)0.0422 (5)0.1258 (4)0.0260 (7)
H12A0.1495140.0264350.0370590.039*
H12B0.3263420.0462790.1164520.039*
H12C0.1919010.0613990.1661120.039*
C130.1592 (5)0.2577 (5)0.3534 (4)0.0265 (7)
H13A0.0810670.3724800.4076510.040*
H13B0.1580690.1556280.3970530.040*
H13C0.2845510.2690870.3447260.040*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.02067 (16)0.02777 (17)0.02333 (17)0.00805 (12)0.00350 (11)0.00432 (12)
C10.0179 (14)0.0207 (14)0.0172 (14)0.0025 (11)0.0001 (11)0.0049 (11)
C20.0169 (14)0.0223 (15)0.0221 (15)0.0023 (11)0.0036 (11)0.0026 (12)
C30.0181 (14)0.0179 (14)0.0245 (15)0.0050 (11)0.0011 (11)0.0042 (12)
C40.0162 (14)0.0169 (14)0.0228 (15)0.0034 (11)0.0005 (11)0.0056 (11)
C50.0146 (13)0.0196 (14)0.0234 (15)0.0029 (11)0.0011 (11)0.0073 (12)
C60.0194 (14)0.0219 (15)0.0249 (16)0.0077 (12)0.0029 (12)0.0055 (12)
C70.0242 (16)0.0199 (15)0.0290 (17)0.0057 (12)0.0057 (13)0.0065 (13)
C80.0198 (15)0.0172 (14)0.0253 (16)0.0014 (11)0.0019 (12)0.0019 (12)
O90.0145 (10)0.0178 (10)0.0331 (13)0.0040 (8)0.0007 (9)0.0088 (9)
C100.0142 (13)0.0214 (15)0.0281 (16)0.0042 (11)0.0002 (11)0.0088 (12)
O110.0159 (11)0.0232 (11)0.0375 (14)0.0019 (9)0.0047 (9)0.0136 (10)
C120.0197 (15)0.0251 (16)0.0309 (18)0.0017 (12)0.0003 (13)0.0064 (13)
C130.0199 (15)0.0303 (17)0.0288 (17)0.0058 (13)0.0034 (13)0.0065 (14)
Geometric parameters (Å, º) top
Br1—C11.917 (3)C6—H6A0.9900
C1—C81.324 (4)C6—H6B0.9900
C1—C21.496 (4)C7—C81.507 (4)
C2—C31.532 (4)C7—H7A0.9900
C2—H2A0.9900C7—H7B0.9900
C2—H2B0.9900C8—H80.9500
C3—C41.519 (4)O9—C101.423 (4)
C3—H3A0.9900C10—O111.433 (4)
C3—H3B0.9900C10—C121.512 (5)
C4—O91.432 (4)C10—C131.521 (5)
C4—C51.531 (4)C12—H12A0.9800
C4—H41.0000C12—H12B0.9800
C5—O111.441 (4)C12—H12C0.9800
C5—C61.518 (4)C13—H13A0.9800
C5—H51.0000C13—H13B0.9800
C6—C71.541 (4)C13—H13C0.9800
C8—C1—C2125.9 (3)C7—C6—H6B108.5
C8—C1—Br1118.7 (2)H6A—C6—H6B107.5
C2—C1—Br1115.3 (2)C8—C7—C6113.1 (3)
C1—C2—C3112.4 (3)C8—C7—H7A109.0
C1—C2—H2A109.1C6—C7—H7A109.0
C3—C2—H2A109.1C8—C7—H7B109.0
C1—C2—H2B109.1C6—C7—H7B109.0
C3—C2—H2B109.1H7A—C7—H7B107.8
H2A—C2—H2B107.9C1—C8—C7123.8 (3)
C4—C3—C2114.7 (3)C1—C8—H8118.1
C4—C3—H3A108.6C7—C8—H8118.1
C2—C3—H3A108.6C10—O9—C4106.7 (2)
C4—C3—H3B108.6O9—C10—O11105.1 (2)
C2—C3—H3B108.6O9—C10—C12108.3 (3)
H3A—C3—H3B107.6O11—C10—C12108.9 (3)
O9—C4—C3107.0 (2)O9—C10—C13110.8 (3)
O9—C4—C5103.2 (2)O11—C10—C13110.8 (3)
C3—C4—C5117.5 (3)C12—C10—C13112.7 (3)
O9—C4—H4109.6C10—O11—C5109.5 (2)
C3—C4—H4109.6C10—C12—H12A109.5
C5—C4—H4109.6C10—C12—H12B109.5
O11—C5—C6107.9 (2)H12A—C12—H12B109.5
O11—C5—C4103.7 (2)C10—C12—H12C109.5
C6—C5—C4117.6 (3)H12A—C12—H12C109.5
O11—C5—H5109.1H12B—C12—H12C109.5
C6—C5—H5109.1C10—C13—H13A109.5
C4—C5—H5109.1C10—C13—H13B109.5
C5—C6—C7115.2 (3)H13A—C13—H13B109.5
C5—C6—H6A108.5C10—C13—H13C109.5
C7—C6—H6A108.5H13A—C13—H13C109.5
C5—C6—H6B108.5H13B—C13—H13C109.5
C8—C1—C2—C390.1 (4)Br1—C1—C8—C7177.4 (2)
Br1—C1—C2—C386.3 (3)C6—C7—C8—C183.7 (4)
C1—C2—C3—C446.3 (4)C3—C4—O9—C10158.8 (2)
C2—C3—C4—O9170.9 (3)C5—C4—O9—C1034.3 (3)
C2—C3—C4—C555.6 (4)C4—O9—C10—O1132.6 (3)
O9—C4—C5—O1122.7 (3)C4—O9—C10—C12148.9 (3)
C3—C4—C5—O11140.1 (3)C4—O9—C10—C1387.1 (3)
O9—C4—C5—C6141.8 (3)O9—C10—O11—C517.2 (3)
C3—C4—C5—C6100.8 (3)C12—C10—O11—C5133.1 (3)
O11—C5—C6—C7173.1 (3)C13—C10—O11—C5102.5 (3)
C4—C5—C6—C770.1 (4)C6—C5—O11—C10129.1 (3)
C5—C6—C7—C874.8 (4)C4—C5—O11—C103.6 (3)
C2—C1—C8—C71.2 (5)
 

References

First citationBurla, M. C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De Caro, L., Giacovazzo, C., Polidori, G. & Spagna, R. (2005). J. Appl. Cryst. 38, 381–388.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationGolding, B. T., Sell, C. S. & Sellars, P. J. (1980). J. Chem. Soc. Perkin Trans. 2, pp. 961–970.  CrossRef Google Scholar
First citationMayer, W. & Meier, H. (1989). Chem. Ber. 122, 509–517.  CrossRef CAS Google Scholar
First citationSheldrick, G. M. (2015). Acta Cryst. C71, 3–8.  Web of Science CrossRef IUCr Journals Google Scholar
First citationSpek, A. L. (2020). Acta Cryst. E76, 1–11.  Web of Science CrossRef IUCr Journals Google Scholar
First citationStoe & Cie (2019). X-RED32 and X-AREA. Stoe & Cie, Darmstadt, Germany.  Google Scholar
First citationTakahashi, A., Aso, M., Tanaka, M. & Suemune, H. (2000). Tetrahedron, 56, 1999–2006.  Web of Science CSD CrossRef CAS Google Scholar

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