1,5-Bis(2-formyl­phen­oxy)-3-oxapenta­ne

Abstract

In the title mol­ecule, C₁₈H₁₈O₅, the two aromatic rings are connected by a flexible 3-oxapentane chain. The mol­ecule has a crystallographic twofold rotation axis (C ₂) passing through the central O atom. An intra­molecular C—H⋯O hydrogen bond is observed in the solid state.

Related literature

For related literature, see: Biernat et al. (1992 ▶); Qi et al. (2005 ▶); Jeffrey & Saenger (1991 ▶); Spek (2003 ▶).

Experimental

Crystal data

• C₁₈H₁₈O₅

• M _r = 314.32

• Orthorhombic,

• a = 27.613 (6) Å

• b = 26.404 (5) Å

• c = 4.4313 (9) Å

• V = 3230.8 (11) ų

• Z = 8

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 295 (2) K

• 0.25 × 0.08 × 0.05 mm

Data collection

• Nonius KappaCCD diffractometer

• Absorption correction: none

• 4449 measured reflections

• 1043 independent reflections

• 480 reflections with I > 2σ(I)

• R _int = 0.134

Refinement

• R[F ² > 2σ(F ²)] = 0.051

• wR(F ²) = 0.097

• S = 0.99

• 1043 reflections

• 105 parameters

• H-atom parameters constrained

• Δρ_max = 0.12 e Å⁻³

• Δρ_min = −0.14 e Å⁻³

Data collection: COLLECT (Nonius, 1998 ▶); cell refinement: PHICHI (Duisenberg et al., 2000 ▶); data reduction: EVAL-14 (CCD) (Duisenberg et al., 2003 ▶); program(s) used to solve structure: SHELXS97 (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 ▶).

Supplementary Material

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C9—H9⋯O2	0.93	2.42	2.764 (5)	102

supplementary crystallographic information

Comment

The title molecule is generated by a symmetry operation according to the space group Fdd2. The symmetry operator (0, 1/2, z) applied to the equivalent atoms is a twofold rotation axis passing through the central atom O1 (Fig. 1). Bond lengths and angles are in the ranges reported for analogous structures (Biernat et al., 1992; Qi et al., 2005). The distances involving the C atoms in the central moiety are 1.496 (5) Å for C1—C2, 1.429 (4) Å for C1—O1, and 1.436 (4) Å for C2—O2.

The intramolecular C9—H9···O2 contact observed in the solid state (Fig. 1) is classificated as a non classical hydrogen bond (Jeffrey & Saenger, 1991). This secondary interaction does not affect the torsion angles in the 3-oxapentane chain. The torsion angle for the O2/C2/C1/O1 moiety is -69.3 (3)° and proves the flexibility of the 3-oxapentane chain. The hydrogen bonding geometry of the intramolecular contacts (Jeffrey & Saenger, 1991) with atom O2 as acceptor was calculated with PLATON (Spek, 2003): distances H9···O2 and C9···O2 are 2.42 and 2.764 (5) Å, respectively, and the angle at H9 is 102°.

Experimental

A mixture of 2[2-(2-p-tolylsulfonyloxy)ethoxy]ethanol (1 g, 8.19 mmol), salicylic aldehyde (0.87 g, 2.10 mmol), and K₂CO₃ (0.47 g, 3.40 mmol) in dry MeCN (20 ml) was heated for 12 h under reflux. After the reaction mixture had cooled down to room temperature, it was filtered and the solvent removed under vacuum. The residue was purified by column chromatography (SiO₂, Hexane:EtOAc 1:1) to give the desired product (0.55 g, 83%) as a yellow solid. A single-crystal was isolated after slow evaporation of the crystallization solvent (THF).

Refinement

All hydrogen atoms were geometrically constrained using a riding model, with C—H distances of 0.93 Å for both benzene rings and the aldehyde moieties with U_iso(H) = 1.2U_eq(Csp²), and with C—H distances of 0.97 Å for the ethyl C atoms with U_iso(H) = 1.2U_eq(Csp³).

Figures

Fig. 1.

ORTEP projection of the title molecule. Symmetry equivalent atoms are generated by the symmetry code [-x, 1 - y, z]. Intramolecular bonds are indicated by dashed lines. Thermal ellipsoids are shown at the 50% probability level.

Crystal data

C18H18O5	F000 = 1328
Mr = 314.32	Dx = 1.292 Mg m−3
Orthorhombic, Fdd2	Mo Kα radiation λ = 0.71073 Å
Hall symbol: F 2 -2d	Cell parameters from 50 reflections
a = 27.613 (6) Å	θ = 1–27.5º
b = 26.404 (5) Å	µ = 0.09 mm−1
c = 4.4313 (9) Å	T = 295 (2) K
V = 3230.8 (11) Å3	Plate, yellow
Z = 8	0.25 × 0.08 × 0.05 mm

Data collection

Nonius KappaCCD diffractometer	480 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.134
Monochromator: graphite	θmax = 27.5º
T = 295(2) K	θmin = 3.1º
φ and ω scans with κ offsets	h = −34→35
Absorption correction: none	k = −34→34
4449 measured reflections	l = −5→5
1043 independent reflections

Refinement

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.051	H-atom parameters constrained
wR(F2) = 0.097	w = 1/[σ2(Fo2) + (0.0377P)2] where P = (Fo2 + 2Fc2)/3
S = 0.99	(Δ/σ)max < 0.001
1043 reflections	Δρmax = 0.12 e Å−3
105 parameters	Δρmin = −0.14 e Å−3
Primary atom site location: structure-invariant direct methods	Extinction correction: none

Special details

Experimental. The transformation of the unit cell axes and hkl intensity data were performed by using the matrix (00–1, 010, 100) in order to solve and refine the structure in the standard setting for space group Fdd2.

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.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.03242 (14)	0.47183 (13)	1.1699 (9)	0.0683 (12)
H1A	0.0138	0.4508	1.3069	0.082*
H1B	0.0515	0.4951	1.2902	0.082*
C2	0.06560 (13)	0.43903 (12)	0.9883 (9)	0.0607 (10)
H2A	0.0831	0.4162	1.1207	0.073*
H2B	0.0469	0.4188	0.8472	0.073*
C3	0.13695 (13)	0.44746 (12)	0.6829 (8)	0.0495 (9)
C4	0.14652 (13)	0.39549 (12)	0.6935 (9)	0.0622 (11)
H4	0.1263	0.3740	0.8015	0.075*
C5	0.18651 (15)	0.37623 (15)	0.5414 (11)	0.0773 (13)
H5	0.1930	0.3417	0.5519	0.093*
C6	0.21687 (15)	0.40706 (15)	0.3753 (10)	0.0731 (13)
H6	0.2433	0.3935	0.2739	0.088*
C7	0.20743 (14)	0.45820 (15)	0.3617 (9)	0.0677 (13)
H7	0.2276	0.4791	0.2491	0.081*
C8	0.16770 (12)	0.47928 (12)	0.5159 (10)	0.0523 (10)
C9	0.15870 (14)	0.53391 (13)	0.4966 (13)	0.0834 (14)
H9	0.1323	0.5466	0.6030	0.100*
O1	0.0000	0.5000	0.9830 (7)	0.0529 (9)
O2	0.09910 (9)	0.47057 (7)	0.8266 (6)	0.0563 (7)
O3	0.18230 (10)	0.56356 (10)	0.3560 (9)	0.1276 (15)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.066 (3)	0.085 (3)	0.054 (3)	−0.002 (2)	−0.005 (3)	0.018 (2)
C2	0.059 (2)	0.061 (2)	0.062 (3)	−0.007 (2)	−0.011 (2)	0.023 (2)
C3	0.044 (2)	0.045 (2)	0.059 (3)	0.0026 (19)	−0.018 (2)	0.003 (2)
C4	0.060 (2)	0.044 (2)	0.083 (3)	−0.0005 (18)	−0.018 (3)	0.0096 (19)
C5	0.075 (3)	0.047 (2)	0.110 (4)	0.010 (2)	−0.029 (3)	−0.009 (3)
C6	0.069 (3)	0.066 (3)	0.084 (3)	0.013 (2)	−0.012 (3)	−0.014 (3)
C7	0.051 (3)	0.073 (3)	0.079 (3)	0.002 (2)	−0.006 (2)	0.007 (2)
C8	0.0426 (19)	0.049 (2)	0.066 (2)	0.0020 (18)	−0.014 (2)	0.011 (2)
C9	0.059 (3)	0.053 (3)	0.138 (4)	0.004 (2)	0.011 (3)	0.023 (3)
O1	0.0469 (17)	0.066 (2)	0.0457 (19)	−0.0031 (18)	0.000	0.000
O2	0.0481 (13)	0.0462 (13)	0.0746 (18)	−0.0005 (12)	0.0020 (13)	0.0170 (14)
O3	0.090 (2)	0.0707 (18)	0.222 (4)	0.0013 (17)	0.043 (3)	0.068 (2)

Geometric parameters (Å, °)

C1—O1	1.429 (4)	C4—H4	0.9300
C1—C2	1.496 (5)	C5—C6	1.381 (5)
C1—H1A	0.9700	C5—H5	0.9300
C1—H1B	0.9700	C6—C7	1.377 (4)
C2—O2	1.436 (4)	C6—H6	0.9300
C2—H2A	0.9700	C7—C8	1.407 (5)
C2—H2B	0.9700	C7—H7	0.9300
C3—O2	1.368 (4)	C8—C9	1.466 (4)
C3—C4	1.398 (4)	C9—O3	1.194 (4)
C3—C8	1.405 (4)	C9—H9	0.9300
C4—C5	1.390 (5)	O1—C1i	1.429 (4)
O1—C1—C2	111.9 (3)	C6—C5—C4	121.7 (4)
O1—C1—H1A	109.2	C6—C5—H5	119.2
C2—C1—H1A	109.2	C4—C5—H5	119.2
O1—C1—H1B	109.2	C7—C6—C5	119.1 (4)
C2—C1—H1B	109.2	C7—C6—H6	120.4
H1A—C1—H1B	107.9	C5—C6—H6	120.4
O2—C2—C1	109.1 (3)	C6—C7—C8	121.0 (4)
O2—C2—H2A	109.9	C6—C7—H7	119.5
C1—C2—H2A	109.9	C8—C7—H7	119.5
O2—C2—H2B	109.9	C3—C8—C7	119.4 (3)
C1—C2—H2B	109.9	C3—C8—C9	121.1 (4)
H2A—C2—H2B	108.3	C7—C8—C9	119.5 (4)
O2—C3—C4	124.5 (3)	O3—C9—C8	125.7 (4)
O2—C3—C8	116.1 (3)	O3—C9—H9	117.2
C4—C3—C8	119.4 (3)	C8—C9—H9	117.2
C5—C4—C3	119.5 (3)	C1i—O1—C1	109.1 (4)
C5—C4—H4	120.2	C3—O2—C2	117.8 (2)
C3—C4—H4	120.2
O1—C1—C2—O2	69.3 (3)	C4—C3—C8—C9	179.4 (4)
O2—C3—C4—C5	−179.1 (3)	C6—C7—C8—C3	−0.8 (6)
C8—C3—C4—C5	0.7 (5)	C6—C7—C8—C9	−180.0 (4)
C3—C4—C5—C6	−1.0 (6)	C3—C8—C9—O3	−178.5 (4)
C4—C5—C6—C7	0.5 (6)	C7—C8—C9—O3	0.6 (7)
C5—C6—C7—C8	0.4 (6)	C2—C1—O1—C1i	176.7 (3)
O2—C3—C8—C7	−180.0 (3)	C4—C3—O2—C2	−3.0 (5)
C4—C3—C8—C7	0.2 (5)	C8—C3—O2—C2	177.2 (3)
O2—C3—C8—C9	−0.8 (5)	C1—C2—O2—C3	170.5 (3)

Symmetry codes: (i) −x, −y+1, z.

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
C9—H9···O2	0.93	2.42	2.764 (5)	102