organic compounds
4-Benzyloxy-1-oxaspiro[4.6]undec-3-en-2-one
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
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 C—H⋯O and C—H⋯π hydrogen bonds generate layers in the ac plane.
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).
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]. These double chains, shown in orange and green in Fig. 4, are further arranged back-to-back forming a layer structure.
The PDF-4/Organics (ICDD, 2012) 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 using silica gel (60 to 120 mesh) and hexane–ethyl acetate (5:1) as eluents to afford the pure title compound (yield 70%). Rf = 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 .
details are summarized in Table 2
|
Structural data
CCDC reference: 1507508
https://doi.org/10.1107/S2414314616015388/sj4054sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314616015388/sj4054Isup2.hkl
Data collection: CrystalClear-SM Expert (Rigaku, 2015); cell
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).C17H20O3 | F(000) = 584 |
Mr = 272.33 | Dx = 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 |
Rigaku Pilatus 200K diffractometer | 2663 independent reflections |
Confocal monochromator | 1961 reflections with I > 2σ(I) |
Detector resolution: 5.8140 pixels mm-1 | Rint = 0.028 |
profile data from ω–scans | θmax = 68.0°, θmin = 7.0° |
Absorption correction: analytical (Alcock, 1974) | h = −15→14 |
Tmin = 0.653, Tmax = 1.000 | k = −7→6 |
10788 measured reflections | l = −23→23 |
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 | Δρmax = 0.43 e Å−3 |
2663 reflections | Δρmin = −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) |
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. |
x | y | z | Uiso*/Ueq | ||
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* |
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) |
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) |
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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