4-Benz­yloxy-1-oxa­spiro­[4.6]undec-3-en-2-one

Quintana Mendoza, J.H.; Henao, J.A.; Robles Marin, E.; Urbina Gonzalez, J.M.

doi:10.1107/S2414314616015388

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 1| Part 10| October 2016| x161538

https://doi.org/10.1107/S2414314616015388

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4-Benzyloxy-1-oxaspiro[4.6]undec-3-en-2-one

Jose H. Quintana Mendoza,^a ^* J. A. Henao,^a Elvis Robles Marin ^b and Juan Manuel Urbina Gonzalez ^b

^aGrupo de Investigacion en Quimica Estructural (GIQUE), Escuela de Quimica, Facultad de Ciencias, Universidad Industrial de Santander, A.P. 680002, Carrera 27, Calle 9 Ciudadela Universitaria, Bucaramanga, Colombia, and ^bLaboratorio de Quimica Organica y Biomolecular (LQOBio), Escuela de Quimica, Facultad de Ciencias, Universidad Industrial de Santander, A.P. 680002, Carrera 27, Calle 9 Ciudadela Universitaria, Bucaramanga, Colombia
^*Correspondence e-mail: josehernandoquintana@gmail.com

Edited by J. Simpson, University of Otago, New Zealand (Received 5 September 2016; accepted 30 September 2016; online 4 October 2016)

The title compound, C₁₇H₂₀O₃, the cycloheptane ring adopts a slightly distorted chair conformation. The planar five-membered ring is inclined at 57.13 (11)° to the phenyl ring of the benzyloxy substituent. In the crystal structure, C—H⋯O and C—H⋯π hydrogen bonds generate layers in the ac plane.

Keywords: crystal structure; 4-benzyloxy-1-oxaspiro[4.6]undec-3-en-2-one; hydrogen bonds.

CCDC reference: 1507508

Structure description

The 4-hydroxyfuran-2[5H]-one core (β-tetronic acid) is present in diverse compounds isolated from natural products. These compounds have shown a variety of biological activities (Schobert & Schlenk, 2008 ). The synthesis and structural analysis of related derivatives continues to be of significant interest. Although several methodologies have been reported for their preparation, most of them use expensive organic starting materials as the synthesis is complex (Tejedor & García-Tellado, 2004 ). α-Hydroxyesters and their cycloalkane derivatives can be easily prepared and then used for the direct synthesis of butenolides (furan-2[5H]-ones) through an addition followed by a Wittig olefination reaction using the accumulated ylide Ph₃P=C=C=O; the use of cycloalkane-α-hydroxyesters allows the preparation of spiro systems of analogous substances with antiviral and anticancer activities among their most important properties (Schobert, 2007 ).

In the title compound (Fig. 1), the cycloheptane ring adopts a slightly distorted chair conformation with q2 = 0.438 (3) Å and φ = 20.8 (4)°. The orientation of the five-membered ring (O1/C1/C4/C3/C2) with respect to the cycloheptane ring is similar to that reported by Schobert et al. (2001 ) for spiro-compounds with seven membered rings. The mean plane of the five-membered ring forms a dihedral angle of 57.13 (11)° with the phenyl ring of the benzyloxy substituent. In the molecule there is a very weak C9—H9B⋯O1 contact present (Table 1).

Table 1
Hydrogen-bond geometry (Å, °)

Cg2 is the centroid of the benzene ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C9—H9B⋯O1	0.97	2.56	2.987 (3)	106
C16—H16⋯O2ⁱ	0.93	2.53	3.362 (3)	149
C7—H7B⋯Cg2ⁱⁱ	0.97	2.80	3.750 (3)	165
Symmetry codes: (i) $[x+{\script{1\over 2}}, -y+{\script{3\over 2}}, z+{\script{1\over 2}}]$ ; (ii) -x+2, -y+1, -z+1.

Figure 1
View of the title compound with the atom-numbering scheme. Displacement ellipsoids for non-H atoms are drawn at the 50% probability level.

In the crystal, molecules are connected by C16—H16⋯O2 contacts, generating zigzag C(10) chains parallel to the c axis (Fig. 2). C7—H7B⋯π interactions form between the cycloheptane ring and the centroid Cg2 of the benzene ring. These contacts link the molecules into dimers, forming inversion dimers (Fig. 3), and creating double chains of molecules approximately along [01 $[\overline1]$ ]. These double chains, shown in orange and green in Fig. 4, are further arranged back-to-back forming a layer structure.

Figure 2
A view of the C—H⋯O hydrogen-bonded chain in the crystal structure of the title compound (see Table 1

Figure 3
Inversion dimers formed by C—H⋯π interactions.

Figure 4
A view along the b axis showing the separate zigzag chains.

The PDF-4/Organics (ICDD, 2012 $[ICDD (2012). PDF-4/Organics 2012 (Database), edited by S. Kabekkodu, International Centre for Diffraction Data, Newtown Square, PA, USA.]$ ) and the Cambridge Structural Database (CSD) (Groom et al. 2016 ) both confirm that this is the first report of the structure of this material.

Synthesis and crystallization

In a 250 ml Schlenk round-bottom flask under an argon atmosphere, 2.18 g (7.21 mmol) of keteneylidenetriphenylphosphorane (Ph₃P=C=C=O) and 150 ml of anhydrous toluene (freshly distilled over sodium) were added and stirred magnetically. 0.87 g (3.50 mmol) of benzyl-1-hydroxycycloheptanecarboxylate, previously dried under vacuum for 1 h, were then added. The reaction mixture was heated under reflux for 72 h (completion of the reaction was monitored by thin-layer chromatography). Toluene was removed by rotary evaporation. Triphenylphosphine oxide (TPPO) formed during the reaction was removed by dissolving the reaction residue in methylene chloride and then filtering it through a small column of silica gel (60 to 120 mesh). The methylene chloride was removed by rotary evaporation and the residual crude product was purified by column chromatography using silica gel (60 to 120 mesh) and hexane–ethyl acetate (5:1) as eluents to afford the pure title compound (yield 70%). R_f = 0.4 (SiO₂, hexane:ethyl acetate, 5:2). Colourless plate-shaped crystals were grown by slow evaporation in air at room temperature from a 1:1 ethyl acetate:ethanol solution [61% yield, m.p. 368 K].

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	C₁₇H₂₀O₃
M_r	272.33
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	298
a, b, c (Å)	13.1661 (9), 5.9457 (4), 19.6730 (13)
β (°)	105.774 (3)
V (Å³)	1482.04 (17)
Z	4
Radiation type	Cu Kα
μ (mm⁻¹)	0.66
Crystal size (mm)	0.26 × 0.17 × 0.08

Data collection
Diffractometer	Rigaku Pilatus 200K
Absorption correction	Analytical (Alcock, 1974 )
T_min, T_max	0.653, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	10788, 2663, 1961
R_int	0.028
(sin θ/λ)_max (Å⁻¹)	0.601

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.047, 0.159, 1.12
No. of reflections	2663
No. of parameters	182
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.43, −0.19
Computer programs: CrystalClear-SM Expert (Rigaku, 2015 ), SHELXT (Sheldrick, 2015a ), SHELXL2014 (Sheldrick, 2015b ) and PLATON (Spek, 2009 ).

Structural data

CCDC reference: 1507508

Crystal structure: contains datablocks global, I. DOI: https://doi.org/10.1107/S2414314616015388/sj4054sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314616015388/sj4054Isup2.hkl

checkCIF report

Computing details top

Data collection: CrystalClear-SM Expert (Rigaku, 2015); cell refinement: CrystalClear-SM Expert (Rigaku, 2015); data reduction: CrystalClear-SM Expert (Rigaku, 2015); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: SHELXL2014 (Sheldrick, 2015b); software used to prepare material for publication: PLATON (Spek, 2009).

4-Benzyloxy-1-oxaspiro[4.6]undec-3-en-2-one top

Crystal data top

C₁₇H₂₀O₃	F(000) = 584
M_r = 272.33	D_x = 1.220 Mg m⁻³
Monoclinic, P2₁/n	Cu Kα radiation, λ = 1.54187 Å
Hall symbol: -P 2yn	Cell parameters from 75 reflections
a = 13.1661 (9) Å	θ = 6.6–68.3°
b = 5.9457 (4) Å	µ = 0.66 mm⁻¹
c = 19.6730 (13) Å	T = 298 K
β = 105.774 (3)°	Plate, colorless
V = 1482.04 (17) Å³	0.26 × 0.17 × 0.08 mm
Z = 4

Data collection top

Rigaku Pilatus 200K diffractometer	2663 independent reflections
Confocal monochromator	1961 reflections with I > 2σ(I)
Detector resolution: 5.8140 pixels mm^-1	R_int = 0.028
profile data from ω–scans	θ_max = 68.0°, θ_min = 7.0°
Absorption correction: analytical (Alcock, 1974)	h = −15→14
T_min = 0.653, T_max = 1.000	k = −7→6
10788 measured reflections	l = −23→23

Refinement top

Refinement on F²	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F² > 2σ(F²)] = 0.047	W = 1/[Σ²(FO²) + (0.0944P)² + 0.0383P] WHERE P = (FO² + 2FC²)/3
wR(F²) = 0.159	(Δ/σ)_max < 0.001
S = 1.12	Δρ_max = 0.43 e Å⁻³
2663 reflections	Δρ_min = −0.19 e Å⁻³
182 parameters	Extinction correction: shelxl-2014/7 (Sheldrick 2015a, FC^*=KFC[1+0.001XFC²Λ³/SIN(2Θ)]^-1/4
0 restraints	Extinction coefficient: 0.0055 (12)

Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell esds are taken into account in the estimation of distances, angles and torsion angles

Refinement. Refinement on F² for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The observed criterion of F² > 2sigma(F²) is used only for calculating -R-factor-obs 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 (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.65557 (10)	0.7811 (2)	0.39735 (6)	0.0587 (4)
O2	0.51051 (14)	0.9560 (3)	0.40696 (9)	0.0926 (7)
O3	0.75329 (9)	0.4593 (2)	0.55237 (6)	0.0586 (4)
C1	0.73395 (13)	0.6282 (3)	0.43863 (9)	0.0466 (5)
C2	0.58293 (15)	0.8307 (3)	0.43300 (11)	0.0616 (7)
C3	0.60803 (14)	0.7127 (3)	0.49933 (10)	0.0572 (6)
C4	0.69565 (13)	0.5954 (3)	0.50349 (9)	0.0483 (5)
C5	0.84009 (14)	0.7456 (4)	0.45714 (10)	0.0615 (7)
C6	0.8889 (2)	0.7882 (5)	0.39683 (17)	0.0958 (11)
C7	0.9329 (2)	0.5925 (6)	0.36911 (17)	0.1085 (13)
C8	0.8603 (3)	0.4293 (5)	0.32391 (18)	0.1036 (12)
C9	0.7490 (2)	0.4241 (5)	0.32610 (13)	0.0845 (9)
C10	0.72762 (17)	0.4081 (3)	0.39760 (11)	0.0616 (7)
C11	0.71428 (15)	0.4155 (4)	0.61342 (10)	0.0626 (7)
C12	0.79198 (13)	0.2632 (3)	0.66139 (9)	0.0481 (5)
C13	0.81346 (15)	0.0543 (3)	0.63809 (10)	0.0573 (6)
C14	0.88756 (17)	−0.0856 (3)	0.68052 (12)	0.0673 (7)
C15	0.94012 (16)	−0.0186 (4)	0.74684 (12)	0.0668 (7)
C16	0.91935 (16)	0.1878 (4)	0.77136 (10)	0.0647 (7)
C17	0.84535 (15)	0.3281 (3)	0.72885 (9)	0.0555 (6)
H3	0.57020	0.71750	0.53290	0.0690*
H5A	0.88920	0.65620	0.49250	0.0740*
H5B	0.83240	0.88920	0.47860	0.0740*
H6A	0.83550	0.85530	0.35820	0.1150*
H6B	0.94480	0.89810	0.41250	0.1150*
H7A	0.97630	0.51050	0.40920	0.1300*
H7B	0.97960	0.64850	0.34240	0.1300*
H8A	0.88950	0.28020	0.33610	0.1240*
H8B	0.86070	0.45740	0.27540	0.1240*
H9A	0.71510	0.29710	0.29810	0.1010*
H9B	0.71490	0.55910	0.30310	0.1010*
H10A	0.77770	0.30310	0.42630	0.0740*
H10B	0.65770	0.34520	0.39110	0.0740*
H11A	0.64540	0.34440	0.59890	0.0750*
H11B	0.70780	0.55500	0.63740	0.0750*
H13	0.77730	0.00710	0.59290	0.0690*
H14	0.90160	−0.22540	0.66390	0.0810*
H15	0.99020	−0.11260	0.77560	0.0800*
H16	0.95530	0.23310	0.81680	0.0780*
H17	0.83140	0.46740	0.74580	0.0670*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0626 (8)	0.0623 (8)	0.0523 (7)	0.0119 (6)	0.0175 (6)	0.0119 (6)
O2	0.0841 (11)	0.1050 (13)	0.0885 (11)	0.0474 (10)	0.0234 (9)	0.0288 (10)
O3	0.0541 (7)	0.0765 (9)	0.0513 (7)	0.0182 (6)	0.0248 (6)	0.0183 (6)
C1	0.0483 (9)	0.0480 (10)	0.0446 (9)	0.0035 (7)	0.0146 (7)	0.0037 (7)
C2	0.0574 (11)	0.0630 (12)	0.0641 (12)	0.0134 (10)	0.0159 (9)	0.0070 (10)
C3	0.0516 (10)	0.0673 (13)	0.0567 (10)	0.0096 (9)	0.0215 (8)	0.0037 (9)
C4	0.0460 (9)	0.0526 (10)	0.0478 (9)	0.0035 (7)	0.0154 (7)	0.0037 (8)
C5	0.0572 (11)	0.0668 (12)	0.0639 (11)	−0.0080 (9)	0.0223 (9)	−0.0029 (10)
C6	0.0947 (18)	0.0952 (19)	0.112 (2)	−0.0267 (15)	0.0528 (16)	0.0020 (16)
C7	0.0777 (16)	0.158 (3)	0.108 (2)	0.0046 (18)	0.0564 (16)	−0.013 (2)
C8	0.113 (2)	0.102 (2)	0.120 (2)	0.0209 (18)	0.0730 (19)	−0.0032 (18)
C9	0.0960 (17)	0.0951 (17)	0.0661 (14)	0.0017 (14)	0.0285 (12)	−0.0249 (12)
C10	0.0660 (12)	0.0567 (12)	0.0653 (12)	−0.0034 (9)	0.0233 (9)	−0.0069 (9)
C11	0.0586 (11)	0.0801 (14)	0.0582 (11)	0.0134 (10)	0.0316 (9)	0.0172 (10)
C12	0.0488 (9)	0.0545 (10)	0.0464 (9)	−0.0010 (8)	0.0223 (7)	0.0063 (8)
C13	0.0629 (11)	0.0596 (12)	0.0493 (10)	−0.0065 (9)	0.0152 (8)	−0.0085 (9)
C14	0.0763 (13)	0.0526 (11)	0.0777 (14)	0.0053 (10)	0.0291 (11)	0.0011 (10)
C15	0.0568 (11)	0.0761 (14)	0.0664 (13)	0.0054 (10)	0.0150 (10)	0.0205 (11)
C16	0.0640 (12)	0.0853 (15)	0.0430 (9)	−0.0158 (11)	0.0115 (8)	0.0021 (10)
C17	0.0721 (12)	0.0531 (10)	0.0494 (10)	−0.0067 (9)	0.0303 (9)	−0.0041 (8)

Geometric parameters (Å, º) top

O1—C1	1.448 (2)	C16—C17	1.379 (3)
O1—C2	1.363 (2)	C3—H3	0.9300
O2—C2	1.209 (3)	C5—H5A	0.9700
O3—C4	1.326 (2)	C5—H5B	0.9700
O3—C11	1.452 (2)	C6—H6A	0.9700
C1—C4	1.507 (2)	C6—H6B	0.9700
C1—C5	1.515 (3)	C7—H7A	0.9700
C1—C10	1.528 (3)	C7—H7B	0.9700
C2—C3	1.439 (3)	C8—H8A	0.9700
C3—C4	1.331 (3)	C8—H8B	0.9700
C5—C6	1.516 (4)	C9—H9A	0.9700
C6—C7	1.469 (4)	C9—H9B	0.9700
C7—C8	1.478 (5)	C10—H10A	0.9700
C8—C9	1.478 (5)	C10—H10B	0.9700
C9—C10	1.511 (3)	C11—H11A	0.9700
C11—C12	1.494 (3)	C11—H11B	0.9700
C12—C13	1.380 (3)	C13—H13	0.9300
C12—C17	1.377 (2)	C14—H14	0.9300
C13—C14	1.378 (3)	C15—H15	0.9300
C14—C15	1.360 (3)	C16—H16	0.9300
C15—C16	1.373 (3)	C17—H17	0.9300

C1—O1—C2	109.88 (13)	C7—C6—H6A	108.00
C4—O3—C11	116.60 (14)	C7—C6—H6B	108.00
O1—C1—C4	101.81 (14)	H6A—C6—H6B	107.00
O1—C1—C5	108.41 (15)	C6—C7—H7A	108.00
O1—C1—C10	108.26 (14)	C6—C7—H7B	108.00
C4—C1—C5	110.81 (15)	C8—C7—H7A	108.00
C4—C1—C10	110.72 (15)	C8—C7—H7B	108.00
C5—C1—C10	115.84 (16)	H7A—C7—H7B	107.00
O1—C2—O2	119.88 (19)	C7—C8—H8A	108.00
O1—C2—C3	109.93 (16)	C7—C8—H8B	108.00
O2—C2—C3	130.2 (2)	C9—C8—H8A	108.00
C2—C3—C4	107.02 (17)	C9—C8—H8B	108.00
O3—C4—C1	115.83 (15)	H8A—C8—H8B	107.00
O3—C4—C3	132.82 (17)	C8—C9—H9A	108.00
C1—C4—C3	111.35 (16)	C8—C9—H9B	108.00
C1—C5—C6	116.63 (18)	C10—C9—H9A	108.00
C5—C6—C7	116.9 (3)	C10—C9—H9B	108.00
C6—C7—C8	119.2 (3)	H9A—C9—H9B	107.00
C7—C8—C9	118.7 (3)	C1—C10—H10A	108.00
C8—C9—C10	117.8 (2)	C1—C10—H10B	108.00
C1—C10—C9	116.15 (18)	C9—C10—H10A	108.00
O3—C11—C12	107.20 (15)	C9—C10—H10B	108.00
C11—C12—C13	120.19 (16)	H10A—C10—H10B	107.00
C11—C12—C17	121.41 (17)	O3—C11—H11A	110.00
C13—C12—C17	118.39 (17)	O3—C11—H11B	110.00
C12—C13—C14	121.18 (18)	C12—C11—H11A	110.00
C13—C14—C15	119.76 (19)	C12—C11—H11B	110.00
C14—C15—C16	120.1 (2)	H11A—C11—H11B	108.00
C15—C16—C17	120.20 (18)	C12—C13—H13	119.00
C12—C17—C16	120.41 (17)	C14—C13—H13	119.00
C2—C3—H3	126.00	C13—C14—H14	120.00
C4—C3—H3	127.00	C15—C14—H14	120.00
C1—C5—H5A	108.00	C14—C15—H15	120.00
C1—C5—H5B	108.00	C16—C15—H15	120.00
C6—C5—H5A	108.00	C15—C16—H16	120.00
C6—C5—H5B	108.00	C17—C16—H16	120.00
H5A—C5—H5B	107.00	C12—C17—H17	120.00
C5—C6—H6A	108.00	C16—C17—H17	120.00
C5—C6—H6B	108.00

C2—O1—C1—C4	0.28 (18)	O1—C2—C3—C4	0.6 (2)
C2—O1—C1—C5	−116.60 (16)	O2—C2—C3—C4	179.7 (2)
C2—O1—C1—C10	117.00 (16)	C2—C3—C4—O3	179.77 (19)
C1—O1—C2—O2	−179.77 (18)	C2—C3—C4—C1	−0.4 (2)
C1—O1—C2—C3	−0.6 (2)	C1—C5—C6—C7	−73.6 (3)
C11—O3—C4—C1	−176.58 (15)	C5—C6—C7—C8	75.0 (4)
C11—O3—C4—C3	3.2 (3)	C6—C7—C8—C9	−19.3 (4)
C4—O3—C11—C12	−179.01 (15)	C7—C8—C9—C10	−51.0 (4)
O1—C1—C4—O3	179.95 (15)	C8—C9—C10—C1	81.3 (3)
O1—C1—C4—C3	0.11 (19)	O3—C11—C12—C13	−60.0 (2)
C5—C1—C4—O3	−64.9 (2)	O3—C11—C12—C17	118.58 (19)
C5—C1—C4—C3	115.24 (18)	C11—C12—C13—C14	177.65 (19)
C10—C1—C4—O3	65.0 (2)	C17—C12—C13—C14	−1.0 (3)
C10—C1—C4—C3	−114.81 (18)	C11—C12—C17—C16	−177.78 (19)
O1—C1—C5—C6	−69.6 (2)	C13—C12—C17—C16	0.9 (3)
C4—C1—C5—C6	179.51 (19)	C12—C13—C14—C15	0.6 (3)
C10—C1—C5—C6	52.3 (3)	C13—C14—C15—C16	0.0 (3)
O1—C1—C10—C9	60.9 (2)	C14—C15—C16—C17	−0.1 (3)
C4—C1—C10—C9	171.67 (18)	C15—C16—C17—C12	−0.3 (3)
C5—C1—C10—C9	−61.1 (2)

Hydrogen-bond geometry (Å, º) top

Cg2 is the centroid of the benzene ring.

D—H···A	D—H	H···A	D···A	D—H···A
C9—H9B···O1	0.97	2.56	2.987 (3)	106
C16—H16···O2ⁱ	0.93	2.53	3.362 (3)	149
C7—H7B···Cg2ⁱⁱ	0.97	2.80	3.750 (3)	165

Symmetry codes: (i) x+1/2, −y+3/2, z+1/2; (ii) −x+2, −y+1, −z+1.

Acknowledgements

The authors acknowledge the support of the Vicerrectoría de Investigación y Extensión, Universidad Industrial de Santander (UIS) and the Parque Tecnológico Guatiguará, UIS, Piedecuesta, Santander, Colombia, Laboratorio de Difracción de Rayos-X, for recording X-ray diffraction data.

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