Ethyl 2-(3-acetyl-6-methyl-2-oxo-2H-pyran-4-yl­oxy)acetate

Rabnawaz, M.; Benson, S.D.; Khan, B.; Shah, M.R.

doi:10.1107/S1600536810001601

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 66| Part 2| February 2010| Page o397

https://doi.org/10.1107/S1600536810001601

Open

access

Ethyl 2-(3-acetyl-6-methyl-2-oxo-2H-pyran-4-yloxy)acetate

Muhammad Rabnawaz,^a Stacy D. Benson,^b Burhan Khan ^a and Muhammad Raza Shah ^a ^*

^aH.E.J. Research Institute of Chemistry, International Center for Chemical and Biological Sciences, University of Karachi, Karachi 75270, Pakistan, and ^bOklahoma State University, Department of Chemistry, 107 Physical Sciences, Stillwater, OK 74078-3071, USA
^*Correspondence e-mail: raza_shahm@yahoo.com

(Received 12 January 2010; accepted 13 January 2010; online 20 January 2010)

The title compound, C₁₂H₁₄O₆, features a roughly planar molecule (r.m.s. deviation for all non-H atoms = 0.287 Å). In the crystal, the molecules are held together by C—H⋯O hydrogen bonds.

Related literature

For the use of dehydroacetic acid as a starting material in the synthesis of heterocyclic ring systems, see: Prakash et al. (2004 ), and of biologically important molecules such as coumarins, see: Hernandez-Galan et al. (1993 ).

Experimental

Crystal data

C₁₂H₁₄O₆
M_r = 254.23
Triclinic, $[P \overline 1]$
a = 7.8258 (10) Å
b = 8.2722 (11) Å
c = 10.0838 (13) Å
α = 77.374 (7)°
β = 77.759 (6)°
γ = 88.857 (7)°
V = 622.28 (14) Å³
Z = 2
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 298 K
0.72 × 0.13 × 0.11 mm

Data collection

Bruker SMART APEXII diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2001 ) T_min = 0.925, T_max = 0.988
14279 measured reflections
3039 independent reflections
2330 reflections with I > 2σ(I)
R_int = 0.036

Refinement

R[F² > 2σ(F²)] = 0.050
wR(F²) = 0.159
S = 1.04
3039 reflections
166 parameters
H-atom parameters constrained
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C6A—H6A1⋯O2ⁱ	0.96	2.53	3.462 (2)	165
C5—H5⋯O3Aⁱ	0.93	2.38	3.3053 (19)	174
C2A—H2A1⋯O3Aⁱ	0.97	2.57	3.355 (2)	138
C2E—H2E2⋯O1ⁱⁱ	0.96	2.54	3.484 (3)	169
Symmetry codes: (i) x+1, y, z; (ii) x+1, y+1, z-1.

Data collection: APEX2 (Bruker, 2008 ); cell refinement: SAINT-Plus (Bruker, 2008); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536810001601/bt5170sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810001601/bt5170Isup2.hkl

checkCIF report

Comment top

3-Acetyl-4-hydroxy-6-methyl-2-oxo-2H-pyran (dehydroacetic acid) is a versatile starting material for the synthesis of a wide variety of heterocyclic ring systems (Prakash et al., 2004) and biologically important molecules like coumarins (Hernandez-Galan et al., 1993).

Related literature top

The title compared was prepared from dehydroacetic acid (3-acetyl-4-hydroxy-6-methyl-2-oxo-2H-pyran) treated with ethylbromoacetate in acetone in the presence of K₂CO₃. For the use of dehydroacetic acid as a starting material in the synthesis of heterocyclic ring systems, see: Prakash et al. (2004), and of biologically important molecules such as coumarins, see: Hernandez-Galan et al. (1993).

Experimental top

The dehydroacetic acid (500 mg, 3 mmol) was treated with ethylbromoacetate (2 g, 12 mmol) in acetone in the presence of K₂CO₃ (1.6 g, 12 mmol). The reaction mixture was refluxed for 3 h monitored with TLC at regular intervals of 30 minutes. The reaction was quenched by addition of 1 N HCl (10 ml) and the aqueous layer was extracted with ethyl acetate three times. The combined organic layers were concentrated under reduced pressure. The crude residue was dissolved in hot ethanol. The slow evaporation of ethanol yielded colorless needle-like crystals (90%, 680 mg).

Structure description top

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT-Plus (Bruker, 2008); data reduction: SAINT-Plus (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

Fig. 1. Crystal Structure of Ethyl 2-(3-acetyl-6-methyl-2-oxo-2H-pyran-4-yloxy) acetate (50% ellipsoids).

Ethyl 2-(3-acetyl-6-methyl-2-oxo-2H-pyran-4-yloxy)acetate top

Crystal data top

C₁₂H₁₄O₆	Z = 2
M_r = 254.23	F(000) = 268
Triclinic, P1	D_x = 1.357 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 7.8258 (10) Å	Cell parameters from 6664 reflections
b = 8.2722 (11) Å	θ = 2.1–28.3°
c = 10.0838 (13) Å	µ = 0.11 mm⁻¹
α = 77.374 (7)°	T = 298 K
β = 77.759 (6)°	Rectangular prism, clear colourless
γ = 88.857 (7)°	0.72 × 0.13 × 0.11 mm
V = 622.28 (14) Å³

Data collection top

Bruker SMART APEXII diffractometer	3039 independent reflections
Radiation source: fine-focus sealed tube	2330 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.036
Detector resolution: 83.33 pixels mm^-1	θ_max = 28.3°, θ_min = 2.1°
φ scans and ω scans with κ offsets	h = −10→10
Absorption correction: multi-scan (SADABS; Bruker, 2001)	k = −11→10
T_min = 0.925, T_max = 0.988	l = −13→13
14279 measured reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.050	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.159	H-atom parameters constrained
S = 1.04	w = 1/[σ²(F_o²) + (0.0773P)² + 0.1512P] where P = (F_o² + 2F_c²)/3
3039 reflections	(Δ/σ)_max < 0.001
166 parameters	Δρ_max = 0.35 e Å⁻³
0 restraints	Δρ_min = −0.20 e Å⁻³

Crystal data top

C₁₂H₁₄O₆	γ = 88.857 (7)°
M_r = 254.23	V = 622.28 (14) Å³
Triclinic, P1	Z = 2
a = 7.8258 (10) Å	Mo Kα radiation
b = 8.2722 (11) Å	µ = 0.11 mm⁻¹
c = 10.0838 (13) Å	T = 298 K
α = 77.374 (7)°	0.72 × 0.13 × 0.11 mm
β = 77.759 (6)°

Data collection top

Bruker SMART APEXII diffractometer	3039 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2001)	2330 reflections with I > 2σ(I)
T_min = 0.925, T_max = 0.988	R_int = 0.036
14279 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.050	0 restraints
wR(F²) = 0.159	H-atom parameters constrained
S = 1.04	Δρ_max = 0.35 e Å⁻³
3039 reflections	Δρ_min = −0.20 e Å⁻³
166 parameters

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.

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 > 2σ(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 (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.57091 (13)	0.60585 (14)	1.11130 (11)	0.0528 (3)
C2	0.44227 (18)	0.6846 (2)	1.04378 (17)	0.0494 (4)
C3	0.50118 (17)	0.81700 (18)	0.92489 (15)	0.0438 (3)
C4	0.67613 (17)	0.86621 (18)	0.89085 (15)	0.0419 (3)
C5	0.79728 (17)	0.78287 (18)	0.96663 (16)	0.0445 (3)
H5	0.9142	0.8175	0.9433	0.053*
C6	0.74139 (18)	0.65385 (19)	1.07210 (15)	0.0453 (3)
C6A	0.8505 (2)	0.5494 (2)	1.15859 (19)	0.0626 (5)
H6A1	0.9708	0.5851	1.1248	0.094*
H6A2	0.8379	0.4358	1.1537	0.094*
H6A3	0.8134	0.5597	1.2534	0.094*
C3A	0.36798 (19)	0.8935 (2)	0.84701 (18)	0.0525 (4)
C3B	0.4174 (3)	0.9705 (5)	0.6972 (3)	0.1171 (12)
H3B1	0.3199	0.9630	0.6548	0.176*
H3B2	0.5145	0.9138	0.6542	0.176*
H3B3	0.4499	1.0849	0.6854	0.176*
O3A	0.21609 (15)	0.8898 (2)	0.90547 (17)	0.0803 (5)
O4	0.72493 (13)	0.99457 (14)	0.78399 (13)	0.0576 (3)
C1A	0.9346 (2)	1.1577 (2)	0.60243 (17)	0.0525 (4)
C2A	0.8981 (2)	1.0641 (2)	0.74992 (18)	0.0562 (4)
H2A1	0.9816	0.9768	0.7622	0.067*
H2A2	0.9088	1.1378	0.8106	0.067*
O2	0.29702 (14)	0.62711 (18)	1.09368 (15)	0.0704 (4)
O1A	0.8501 (2)	1.1503 (2)	0.51873 (16)	0.0947 (6)
O1B	1.08032 (15)	1.24797 (15)	0.57701 (11)	0.0587 (3)
C1E	1.1521 (3)	1.3319 (3)	0.43439 (19)	0.0748 (6)
H1E1	1.0694	1.4101	0.3996	0.090*
H1E2	1.1769	1.2523	0.3755	0.090*
C2E	1.3156 (3)	1.4200 (4)	0.4343 (3)	0.1057 (9)
H2E1	1.2882	1.5037	0.4875	0.159*
H2E2	1.3712	1.4710	0.3404	0.159*
H2E3	1.3930	1.3424	0.4747	0.159*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0358 (5)	0.0632 (7)	0.0518 (6)	−0.0105 (5)	−0.0048 (4)	0.0003 (5)
C2	0.0325 (7)	0.0602 (9)	0.0533 (8)	−0.0079 (6)	−0.0035 (6)	−0.0126 (7)
C3	0.0282 (6)	0.0524 (8)	0.0514 (8)	−0.0040 (6)	−0.0069 (6)	−0.0141 (6)
C4	0.0306 (6)	0.0461 (7)	0.0475 (7)	−0.0052 (5)	−0.0062 (5)	−0.0084 (6)
C5	0.0280 (6)	0.0528 (8)	0.0512 (8)	−0.0071 (5)	−0.0080 (5)	−0.0077 (6)
C6	0.0338 (7)	0.0543 (8)	0.0469 (7)	−0.0054 (6)	−0.0076 (6)	−0.0096 (6)
C6A	0.0500 (9)	0.0741 (11)	0.0578 (10)	−0.0051 (8)	−0.0168 (7)	0.0039 (8)
C3A	0.0312 (7)	0.0618 (9)	0.0665 (10)	−0.0022 (6)	−0.0129 (6)	−0.0156 (8)
C3B	0.0486 (11)	0.212 (3)	0.0718 (14)	0.0101 (15)	−0.0214 (10)	0.0165 (17)
O3A	0.0314 (6)	0.1083 (11)	0.0932 (10)	0.0034 (6)	−0.0130 (6)	−0.0053 (8)
O4	0.0332 (5)	0.0616 (7)	0.0687 (7)	−0.0110 (5)	−0.0157 (5)	0.0110 (5)
C1A	0.0461 (8)	0.0541 (9)	0.0544 (9)	−0.0057 (7)	−0.0108 (7)	−0.0052 (7)
C2A	0.0361 (7)	0.0655 (10)	0.0578 (9)	−0.0158 (7)	−0.0116 (6)	0.0090 (7)
O2	0.0346 (6)	0.0894 (9)	0.0752 (8)	−0.0196 (6)	−0.0017 (5)	−0.0007 (7)
O1A	0.0861 (11)	0.1290 (14)	0.0670 (9)	−0.0384 (10)	−0.0321 (8)	0.0022 (9)
O1B	0.0544 (7)	0.0653 (7)	0.0469 (6)	−0.0197 (5)	−0.0051 (5)	0.0040 (5)
C1E	0.0799 (13)	0.0853 (13)	0.0456 (9)	−0.0179 (10)	−0.0010 (9)	0.0044 (9)
C2E	0.0910 (17)	0.127 (2)	0.0702 (13)	−0.0493 (15)	0.0077 (12)	0.0197 (13)

Geometric parameters (Å, º) top

O1—C6	1.3501 (16)	C3B—H3B1	0.9600
O1—C2	1.404 (2)	C3B—H3B2	0.9600
C2—O2	1.2024 (17)	C3B—H3B3	0.9600
C2—C3	1.436 (2)	O4—C2A	1.4256 (17)
C3—C4	1.3856 (17)	C1A—O1A	1.189 (2)
C3—C3A	1.486 (2)	C1A—O1B	1.3228 (18)
C4—O4	1.3326 (18)	C1A—C2A	1.489 (2)
C4—C5	1.417 (2)	C2A—H2A1	0.9700
C5—C6	1.337 (2)	C2A—H2A2	0.9700
C5—H5	0.9300	O1B—C1E	1.450 (2)
C6—C6A	1.481 (2)	C1E—C2E	1.485 (3)
C6A—H6A1	0.9600	C1E—H1E1	0.9700
C6A—H6A2	0.9600	C1E—H1E2	0.9700
C6A—H6A3	0.9600	C2E—H2E1	0.9600
C3A—O3A	1.2073 (19)	C2E—H2E2	0.9600
C3A—C3B	1.476 (3)	C2E—H2E3	0.9600

C6—O1—C2	122.89 (12)	H3B1—C3B—H3B2	109.5
O2—C2—O1	113.96 (15)	C3A—C3B—H3B3	109.5
O2—C2—C3	129.34 (16)	H3B1—C3B—H3B3	109.5
O1—C2—C3	116.68 (12)	H3B2—C3B—H3B3	109.5
C4—C3—C2	118.59 (13)	C4—O4—C2A	121.02 (12)
C4—C3—C3A	124.32 (14)	O1A—C1A—O1B	124.77 (16)
C2—C3—C3A	117.09 (12)	O1A—C1A—C2A	126.07 (16)
O4—C4—C3	117.09 (13)	O1B—C1A—C2A	109.14 (14)
O4—C4—C5	121.74 (12)	O4—C2A—C1A	108.53 (13)
C3—C4—C5	121.17 (13)	O4—C2A—H2A1	110.0
C6—C5—C4	119.19 (12)	C1A—C2A—H2A1	110.0
C6—C5—H5	120.4	O4—C2A—H2A2	110.0
C4—C5—H5	120.4	C1A—C2A—H2A2	110.0
C5—C6—O1	121.31 (13)	H2A1—C2A—H2A2	108.4
C5—C6—C6A	126.34 (14)	C1A—O1B—C1E	117.97 (14)
O1—C6—C6A	112.35 (13)	O1B—C1E—C2E	107.09 (17)
C6—C6A—H6A1	109.5	O1B—C1E—H1E1	110.3
C6—C6A—H6A2	109.5	C2E—C1E—H1E1	110.3
H6A1—C6A—H6A2	109.5	O1B—C1E—H1E2	110.3
C6—C6A—H6A3	109.5	C2E—C1E—H1E2	110.3
H6A1—C6A—H6A3	109.5	H1E1—C1E—H1E2	108.6
H6A2—C6A—H6A3	109.5	C1E—C2E—H2E1	109.5
O3A—C3A—C3B	118.99 (17)	C1E—C2E—H2E2	109.5
O3A—C3A—C3	119.99 (16)	H2E1—C2E—H2E2	109.5
C3B—C3A—C3	120.99 (14)	C1E—C2E—H2E3	109.5
C3A—C3B—H3B1	109.5	H2E1—C2E—H2E3	109.5
C3A—C3B—H3B2	109.5	H2E2—C2E—H2E3	109.5

C6—O1—C2—O2	−179.01 (14)	C2—O1—C6—C5	1.2 (2)
C6—O1—C2—C3	2.6 (2)	C2—O1—C6—C6A	−179.19 (14)
O2—C2—C3—C4	177.25 (16)	C4—C3—C3A—O3A	−153.29 (17)
O1—C2—C3—C4	−4.6 (2)	C2—C3—C3A—O3A	26.1 (2)
O2—C2—C3—C3A	−2.2 (3)	C4—C3—C3A—C3B	28.5 (3)
O1—C2—C3—C3A	175.96 (13)	C2—C3—C3A—C3B	−152.2 (2)
C2—C3—C4—O4	−176.87 (13)	C3—C4—O4—C2A	173.81 (14)
C3A—C3—C4—O4	2.5 (2)	C5—C4—O4—C2A	−6.3 (2)
C2—C3—C4—C5	3.3 (2)	C4—O4—C2A—C1A	159.18 (14)
C3A—C3—C4—C5	−177.39 (14)	O1A—C1A—C2A—O4	−13.5 (3)
O4—C4—C5—C6	−179.39 (14)	O1B—C1A—C2A—O4	168.37 (13)
C3—C4—C5—C6	0.5 (2)	O1A—C1A—O1B—C1E	−6.2 (3)
C4—C5—C6—O1	−2.8 (2)	C2A—C1A—O1B—C1E	172.01 (16)
C4—C5—C6—C6A	177.66 (16)	C1A—O1B—C1E—C2E	−178.72 (19)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6A—H6A1···O2ⁱ	0.96	2.53	3.462 (2)	165
C5—H5···O3Aⁱ	0.93	2.38	3.3053 (19)	174
C2A—H2A1···O3Aⁱ	0.97	2.57	3.355 (2)	138
C2E—H2E2···O1ⁱⁱ	0.96	2.54	3.484 (3)	169

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

Experimental details

Crystal data
Chemical formula	C₁₂H₁₄O₆
M_r	254.23
Crystal system, space group	Triclinic, P1
Temperature (K)	298
a, b, c (Å)	7.8258 (10), 8.2722 (11), 10.0838 (13)
α, β, γ (°)	77.374 (7), 77.759 (6), 88.857 (7)
V (Å³)	622.28 (14)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.11
Crystal size (mm)	0.72 × 0.13 × 0.11

Data collection
Diffractometer	Bruker SMART APEXII
Absorption correction	Multi-scan (SADABS; Bruker, 2001)
T_min, T_max	0.925, 0.988
No. of measured, independent and observed [I > 2σ(I)] reflections	14279, 3039, 2330
R_int	0.036
(sin θ/λ)_max (Å⁻¹)	0.667

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.050, 0.159, 1.04
No. of reflections	3039
No. of parameters	166
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.35, −0.20

Computer programs: APEX2 (Bruker, 2008), SAINT-Plus (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C6A—H6A1···O2ⁱ	0.9600	2.5300	3.462 (2)	165.00
C5—H5···O3Aⁱ	0.9300	2.3800	3.3053 (19)	174.00
C2A—H2A1···O3Aⁱ	0.9700	2.5700	3.355 (2)	138.00
C2E—H2E2···O1ⁱⁱ	0.9600	2.5400	3.484 (3)	169.00

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

Acknowledgements

The authors thank the Organization for the Prohibition of Chemical Weapons for financial support.

References

Bruker (2001). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2008). APEX2 and SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Hernandez-Galan, R., Salva, J., Massannet, G. M. & Collado, I. G. (1993). Tetrahedron, 49, 1701–1702. CrossRef CAS Web of Science Google Scholar
Prakash, O., Kumar, A. & Singh, S. P. (2004). Heterocycles, 63, 1193–1194. CrossRef CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar