Ethyl (E)-3-hy­droxy-2-[(4-meth­oxy­styr­yl)­carbamo­yl]but-2-enoate

Zhao, S.-Y.; Huang, J.

doi:10.1107/S1600536812006538

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 68| Part 3| March 2012| Page o798

doi:10.1107/S1600536812006538

Open

access

Ethyl (E)-3-hydroxy-2-[(4-methoxystyryl)carbamoyl]but-2-enoate

Sheng-Yin Zhao ^a ^* and Jing Huang ^a

^aCollege of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, People's Republic of China
^*Correspondence e-mail: syzhao8@dhu.edu.cn

(Received 7 December 2011; accepted 14 February 2012; online 24 February 2012)

The title compound, C₁₆H₁₉NO₅, which was synthesized from p-methoxycinnamic acid, has intramolecular O—H⋯O and N—H⋯O hydrogen-bonding interactions. In the crystal, molecules are linked by weak C—H⋯O hydrogen bonds and aromatic π–π stacking interactions [minimum ring centroid–centroid separation = 3.790 (1) Å].

Related literature

For applications of 4-hydroxy-2-pyridones, see: Jessen & Gademann (2010 ). For general background to the synthesis and characterization, see: Rigby & Burkhardt (1986 ); Rigby & Qabar (1989 ); Tang et al. (2011 ).

Experimental

Crystal data

C₁₆H₁₉NO₅
M_r = 305.32
Monoclinic, P 2₁ /n
a = 11.1878 (15) Å
b = 10.5349 (14) Å
c = 13.5586 (18) Å
β = 101.424 (2)°
V = 1566.4 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 293 K
0.31 × 0.27 × 0.25 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2003 ) T_min = 0.733, T_max = 1.000
8234 measured reflections
3064 independent reflections
2489 reflections with I > 2σ(I)
R_int = 0.023

Refinement

R[F² > 2σ(F²)] = 0.043
wR(F²) = 0.122
S = 1.04
3064 reflections
211 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.13 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1A⋯O3	0.893 (17)	1.887 (16)	2.6088 (16)	136.7 (14)
O2—H2A⋯O1	0.95 (2)	1.49 (2)	2.3992 (15)	158 (2)
C1—H1⋯O3ⁱ	0.93	2.49	3.3533 (17)	154
C16—H16B⋯O5ⁱⁱ	0.96	2.59	3.411 (2)	144
Symmetry codes: (i) $[-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (ii) -x+1, -y-1, -z.

Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536812006538/zs2172sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536812006538/zs2172Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536812006538/zs2172Isup3.cml

checkCIF report

Comment top

The title compound, C₁₆H₁₉NO₅ is an important intermediate for the synthesis of 4-hydroxy-2-pyridone derivatives (Jessen & Gademann, 2010). The X-ray structural analysis of this compound reported here confirms the assignment of its structure determined from spectroscopic data (Tang et al., 2011). The conformation of this molecule is stabilized by intramolecular N—H···O and O—H···O hydrogen bonds (Table 1, Fig. 1). In the crystal (Fig. 2), molecules are linked by weak intermolecular C—H···O hydrogen bonds. The layers are further connected into a three-dimensional network by weak π–π stacking interactions down the a axiial direction of the unit cell [minimum centroid separation, 3.790 (1) Å].

Related literature top

For applications of 4-hydroxy-2-pyridones, see: Jessen & Gademann (2010). For general background to the synthesis and characterization, see: Rigby & Burkhardt (1986); Rigby & Qabar (1989); Tang et al. (2011).

Experimental top

The preparation of the title compound follows the procedure of Rigby & Burkhardt (1986) and Rigby & Qabar (1989). To an ice-cooled solution of p-methoxycinnamic acid (2.0 g, 11.2 mmol) in 20 ml of toluene was added triethylamine (1.6 ml, 11.6 mmol) and diphenyl phosphorazidate (DPPA, 2.9 g, 10.5 mmol). The solution was stirred at room temperature for 3 h. The acyl azide product was isolated by dilution with cold water. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was removed in vacuo to provide a crude product. The acyl azide was dissolved in 20 ml of benzene and heated at reflux until azide decomposition was complete as monitored by TLC. The reaction mixture was then cooled to 273 K and ethyl sodioacetocaetate [prepared from ethyl acetoacetate (1.46 g, 11.2 mmol) and sodium hydride (0.37 g, 80% dispersion in oil, 12.3 mmol) in toluene (10 ml) at 273 K] was added. The reaction mixture was allowed to warm to room temperature over 2 h and was then quenched with a saturated aqueous ammonium chloride solution extracted with ether (3 times, 30 ml), rinsed with brine (3 times,30 ml), and dried over anhydrous sodium sulfate. The solvent was removed in vacuo to give white crystals (m.p. 367–369 K). ¹H NMR (DMSO-d₆, 400 MHz): 1.39 (t, 3H, CH₃), 2.49 (s, 3H, CH₃), 3.82 (s, 3H, CH₃), 4.32 (q, 2H, CH₂), 6.21 (d, 1H, =CH), 6.85 (d, 2H, Ar—H), 7.28 (d, 2H, Ar—H), 7.43 (dd, 1H, =CH), 11.04 (d, NH). Crystals suitable for X-ray diffraction were obtained by slow evaporation of a 1:1 ethyl acetate–petroleum ether solution.

Computing details top

Data collection: SMART (Bruker, 2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT (Bruker, 2003); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

	Fig. 1. Molecular structure of the title compound showing the atom labelling scheme. Displacement ellipsoids are drawn at the 30% probability level. Hydrogen bonds are shown as dashed lines.
	Fig. 2. Molecular packing of the title compound viewed down the a axial direction, with intermolecular C—H···O hydrogen-bonding shown as dashed lines.

Ethyl (E)-3-hydroxy-2-[(4-methoxystyryl)carbamoyl]but-2-enoate top

Crystal data top

C₁₆H₁₉NO₅	F(000) = 648
M_r = 305.32	D_x = 1.295 Mg m⁻³
Monoclinic, P2₁/n	Melting point = 367–369 K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 11.1878 (15) Å	Cell parameters from 3146 reflections
b = 10.5349 (14) Å	θ = 4.9–54.1°
c = 13.5586 (18) Å	µ = 0.10 mm⁻¹
β = 101.424 (2)°	T = 293 K
V = 1566.4 (4) Å³	Prismatic, yellow
Z = 4	0.31 × 0.27 × 0.25 mm

Data collection top

Bruker SMART CCD area-detector diffractometer	3064 independent reflections
Radiation source: fine-focus sealed tube	2489 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.023
ϕ and ω scans	θ_max = 26.0°, θ_min = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2003)	h = −12→13
T_min = 0.733, T_max = 1.000	k = −12→12
8234 measured reflections	l = −16→10

Refinement top

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)] = 0.043	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.122	w = 1/[σ²(F_o²) + (0.0681P)² + 0.143P] where P = (F_o² + 2F_c²)/3
S = 1.04	(Δ/σ)_max = 0.025
3064 reflections	Δρ_max = 0.13 e Å⁻³
211 parameters	Δρ_min = −0.18 e Å⁻³
1 restraint	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.100 (6)

Crystal data top

C₁₆H₁₉NO₅	V = 1566.4 (4) Å³
M_r = 305.32	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 11.1878 (15) Å	µ = 0.10 mm⁻¹
b = 10.5349 (14) Å	T = 293 K
c = 13.5586 (18) Å	0.31 × 0.27 × 0.25 mm
β = 101.424 (2)°

Data collection top

Bruker SMART CCD area-detector diffractometer	3064 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2003)	2489 reflections with I > 2σ(I)
T_min = 0.733, T_max = 1.000	R_int = 0.023
8234 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.043	1 restraint
wR(F²) = 0.122	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	Δρ_max = 0.13 e Å⁻³
3064 reflections	Δρ_min = −0.18 e Å⁻³
211 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 > 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 (Å²) top

	x	y	z	U_iso*/U_eq
N1	0.77258 (10)	0.36381 (11)	−0.00047 (9)	0.0537 (3)
O1	0.76724 (11)	0.39921 (10)	−0.16424 (7)	0.0731 (3)
O2	0.83950 (12)	0.59326 (11)	−0.22428 (7)	0.0749 (4)
O3	0.86298 (11)	0.54370 (10)	0.12448 (7)	0.0706 (3)
O4	0.93449 (9)	0.71806 (9)	0.06663 (7)	0.0622 (3)
O5	0.57847 (10)	−0.35005 (9)	0.03629 (8)	0.0684 (3)
C1	0.65197 (14)	−0.02958 (14)	0.13759 (10)	0.0588 (4)
H1	0.6582	0.0155	0.1974	0.071*
C2	0.61898 (13)	−0.15608 (14)	0.13560 (10)	0.0593 (4)
H2	0.6036	−0.1950	0.1934	0.071*
C3	0.60897 (11)	−0.22447 (13)	0.04747 (10)	0.0521 (3)
C4	0.63126 (13)	−0.16397 (14)	−0.03769 (10)	0.0577 (4)
H4	0.6241	−0.2091	−0.0975	0.069*
C5	0.66365 (13)	−0.03854 (14)	−0.03493 (10)	0.0569 (4)
H5	0.6777	0.0002	−0.0932	0.068*
C6	0.67605 (11)	0.03238 (13)	0.05345 (9)	0.0500 (3)
C7	0.71325 (12)	0.16556 (13)	0.06022 (11)	0.0569 (4)
H7	0.7259	0.2023	0.1238	0.068*
C8	0.73077 (12)	0.23922 (13)	−0.01454 (10)	0.0540 (3)
H8	0.7145	0.2064	−0.0795	0.065*
C9	0.79420 (12)	0.43913 (13)	−0.07438 (9)	0.0506 (3)
C10	0.84919 (11)	0.56419 (12)	−0.05171 (8)	0.0456 (3)
C11	0.86942 (12)	0.63708 (13)	−0.13301 (9)	0.0517 (3)
C12	0.92260 (15)	0.76693 (15)	−0.12982 (11)	0.0666 (4)
H12A	1.0067	0.7641	−0.0964	0.100*
H12B	0.8785	0.8226	−0.0938	0.100*
H12C	0.9169	0.7978	−0.1972	0.100*
C13	0.88127 (11)	0.60534 (12)	0.05309 (9)	0.0490 (3)
C14	0.96451 (16)	0.76631 (16)	0.16830 (12)	0.0752 (5)
H14A	1.0243	0.7119	0.2097	0.090*
H14B	0.8922	0.7694	0.1976	0.090*
C15	1.01509 (19)	0.89607 (18)	0.16260 (16)	0.0984 (7)
H15A	1.0839	0.8923	0.1302	0.148*
H15B	1.0404	0.9296	0.2293	0.148*
H15C	0.9536	0.9501	0.1246	0.148*
C16	0.55675 (17)	−0.41682 (16)	0.12183 (12)	0.0745 (5)
H16A	0.6282	−0.4132	0.1743	0.112*
H16B	0.5379	−0.5038	0.1041	0.112*
H16C	0.4894	−0.3787	0.1450	0.112*
H1A	0.7911 (14)	0.3947 (15)	0.0620 (13)	0.067 (4)*
H2A	0.8114 (17)	0.5093 (15)	−0.2163 (15)	0.099 (6)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0602 (7)	0.0506 (7)	0.0500 (7)	−0.0036 (5)	0.0101 (5)	0.0008 (5)
O1	0.1040 (8)	0.0646 (7)	0.0460 (6)	−0.0161 (6)	0.0032 (5)	−0.0052 (4)
O2	0.1071 (9)	0.0762 (8)	0.0392 (5)	−0.0094 (6)	0.0096 (5)	0.0060 (5)
O3	0.1014 (8)	0.0711 (7)	0.0405 (5)	−0.0170 (6)	0.0171 (5)	0.0000 (4)
O4	0.0785 (6)	0.0580 (6)	0.0486 (5)	−0.0123 (5)	0.0089 (5)	−0.0069 (4)
O5	0.0883 (7)	0.0532 (6)	0.0650 (7)	−0.0090 (5)	0.0185 (5)	0.0023 (5)
C1	0.0702 (8)	0.0624 (9)	0.0449 (7)	−0.0065 (7)	0.0137 (6)	−0.0031 (6)
C2	0.0698 (9)	0.0625 (9)	0.0477 (7)	−0.0058 (7)	0.0169 (6)	0.0076 (6)
C3	0.0503 (7)	0.0510 (8)	0.0547 (8)	−0.0002 (5)	0.0099 (6)	0.0040 (6)
C4	0.0700 (8)	0.0582 (9)	0.0457 (7)	0.0000 (7)	0.0131 (6)	−0.0020 (6)
C5	0.0687 (8)	0.0577 (9)	0.0464 (7)	−0.0018 (6)	0.0168 (6)	0.0073 (6)
C6	0.0472 (7)	0.0536 (8)	0.0491 (7)	0.0006 (5)	0.0092 (5)	0.0031 (5)
C7	0.0604 (8)	0.0574 (8)	0.0531 (8)	−0.0051 (6)	0.0115 (6)	−0.0020 (6)
C8	0.0543 (7)	0.0502 (8)	0.0563 (8)	0.0001 (6)	0.0081 (6)	0.0002 (6)
C9	0.0531 (7)	0.0535 (8)	0.0434 (7)	0.0022 (6)	0.0054 (5)	0.0013 (5)
C10	0.0468 (6)	0.0491 (7)	0.0402 (6)	0.0024 (5)	0.0066 (5)	0.0016 (5)
C11	0.0536 (7)	0.0579 (8)	0.0428 (7)	0.0051 (6)	0.0076 (5)	0.0059 (5)
C12	0.0739 (9)	0.0681 (10)	0.0573 (8)	−0.0104 (7)	0.0120 (7)	0.0154 (7)
C13	0.0504 (7)	0.0530 (8)	0.0432 (7)	0.0020 (6)	0.0086 (5)	0.0009 (5)
C14	0.0862 (11)	0.0800 (11)	0.0569 (9)	−0.0040 (9)	0.0079 (8)	−0.0217 (8)
C15	0.0945 (13)	0.0916 (14)	0.1113 (15)	−0.0234 (11)	0.0256 (12)	−0.0477 (12)
C16	0.0902 (11)	0.0601 (10)	0.0751 (10)	−0.0113 (8)	0.0209 (9)	0.0118 (7)

Geometric parameters (Å, º) top

N1—C9	1.3373 (16)	C6—C7	1.4611 (19)
N1—C8	1.3938 (18)	C7—C8	1.3217 (19)
N1—H1A	0.893 (17)	C7—H7	0.9300
O1—C9	1.2676 (16)	C8—H8	0.9300
O2—C11	1.3010 (16)	C9—C10	1.4607 (18)
O2—H2A	0.952 (15)	C10—C11	1.3981 (17)
O3—C13	1.2162 (15)	C10—C13	1.4608 (17)
O4—C13	1.3247 (16)	C11—C12	1.489 (2)
O4—C14	1.4451 (17)	C12—H12A	0.9600
O5—C3	1.3672 (16)	C12—H12B	0.9600
O5—C16	1.4180 (17)	C12—H12C	0.9600
C1—C2	1.382 (2)	C14—C15	1.487 (2)
C1—C6	1.3864 (18)	C14—H14A	0.9700
C1—H1	0.9300	C14—H14B	0.9700
C2—C3	1.3808 (19)	C15—H15A	0.9600
C2—H2	0.9300	C15—H15B	0.9600
C3—C4	1.3841 (18)	C15—H15C	0.9600
C4—C5	1.369 (2)	C16—H16A	0.9600
C4—H4	0.9300	C16—H16B	0.9600
C5—C6	1.3955 (19)	C16—H16C	0.9600
C5—H5	0.9300

C9—N1—C8	124.18 (12)	C11—C10—C13	123.84 (12)
C9—N1—H1A	116.9 (10)	C11—C10—C9	117.17 (11)
C8—N1—H1A	118.8 (10)	C13—C10—C9	118.98 (11)
C11—O2—H2A	104.5 (12)	O2—C11—C10	120.25 (13)
C13—O4—C14	117.43 (11)	O2—C11—C12	112.31 (12)
C3—O5—C16	117.96 (11)	C10—C11—C12	127.44 (12)
C2—C1—C6	122.19 (13)	C11—C12—H12A	109.5
C2—C1—H1	118.9	C11—C12—H12B	109.5
C6—C1—H1	118.9	H12A—C12—H12B	109.5
C3—C2—C1	119.72 (12)	C11—C12—H12C	109.5
C3—C2—H2	120.1	H12A—C12—H12C	109.5
C1—C2—H2	120.1	H12B—C12—H12C	109.5
O5—C3—C2	125.21 (12)	O3—C13—O4	120.68 (12)
O5—C3—C4	115.81 (12)	O3—C13—C10	124.62 (12)
C2—C3—C4	118.98 (13)	O4—C13—C10	114.70 (11)
C5—C4—C3	120.81 (13)	O4—C14—C15	107.02 (14)
C5—C4—H4	119.6	O4—C14—H14A	110.3
C3—C4—H4	119.6	C15—C14—H14A	110.3
C4—C5—C6	121.41 (12)	O4—C14—H14B	110.3
C4—C5—H5	119.3	C15—C14—H14B	110.3
C6—C5—H5	119.3	H14A—C14—H14B	108.6
C1—C6—C5	116.88 (12)	C14—C15—H15A	109.5
C1—C6—C7	119.98 (12)	C14—C15—H15B	109.5
C5—C6—C7	123.14 (12)	H15A—C15—H15B	109.5
C8—C7—C6	126.82 (13)	C14—C15—H15C	109.5
C8—C7—H7	116.6	H15A—C15—H15C	109.5
C6—C7—H7	116.6	H15B—C15—H15C	109.5
C7—C8—N1	123.00 (13)	O5—C16—H16A	109.5
C7—C8—H8	118.5	O5—C16—H16B	109.5
N1—C8—H8	118.5	H16A—C16—H16B	109.5
O1—C9—N1	118.65 (12)	O5—C16—H16C	109.5
O1—C9—C10	120.77 (11)	H16A—C16—H16C	109.5
N1—C9—C10	120.57 (11)	H16B—C16—H16C	109.5

C6—C1—C2—C3	−0.1 (2)	C8—N1—C9—C10	−173.98 (11)
C16—O5—C3—C2	−0.9 (2)	O1—C9—C10—C11	0.50 (19)
C16—O5—C3—C4	178.96 (13)	N1—C9—C10—C11	179.73 (12)
C1—C2—C3—O5	179.24 (13)	O1—C9—C10—C13	−178.68 (12)
C1—C2—C3—C4	−0.6 (2)	N1—C9—C10—C13	0.55 (18)
O5—C3—C4—C5	−179.38 (12)	C13—C10—C11—O2	179.25 (12)
C2—C3—C4—C5	0.5 (2)	C9—C10—C11—O2	0.11 (19)
C3—C4—C5—C6	0.4 (2)	C13—C10—C11—C12	−1.5 (2)
C2—C1—C6—C5	1.0 (2)	C9—C10—C11—C12	179.32 (12)
C2—C1—C6—C7	−178.64 (13)	C14—O4—C13—O3	−2.7 (2)
C4—C5—C6—C1	−1.1 (2)	C14—O4—C13—C10	177.80 (12)
C4—C5—C6—C7	178.50 (13)	C11—C10—C13—O3	179.10 (13)
C1—C6—C7—C8	−174.85 (14)	C9—C10—C13—O3	−1.8 (2)
C5—C6—C7—C8	5.6 (2)	C11—C10—C13—O4	−1.38 (18)
C6—C7—C8—N1	−176.51 (12)	C9—C10—C13—O4	177.74 (11)
C9—N1—C8—C7	178.10 (13)	C13—O4—C14—C15	−176.35 (13)
C8—N1—C9—O1	5.3 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O3	0.893 (17)	1.887 (16)	2.6088 (16)	136.7 (14)
O2—H2A···O1	0.95 (2)	1.49 (2)	2.3992 (15)	158 (2)
C1—H1···O3ⁱ	0.93	2.49	3.3533 (17)	154
C16—H16B···O5ⁱⁱ	0.96	2.59	3.411 (2)	144

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

Experimental details

Crystal data
Chemical formula	C₁₆H₁₉NO₅
M_r	305.32
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	293
a, b, c (Å)	11.1878 (15), 10.5349 (14), 13.5586 (18)
β (°)	101.424 (2)
V (Å³)	1566.4 (4)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.31 × 0.27 × 0.25

Data collection
Diffractometer	Bruker SMART CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2003)
T_min, T_max	0.733, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	8234, 3064, 2489
R_int	0.023
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.043, 0.122, 1.04
No. of reflections	3064
No. of parameters	211
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.13, −0.18

Computer programs: SMART (Bruker, 2003), SAINT (Bruker, 2003), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O3	0.893 (17)	1.887 (16)	2.6088 (16)	136.7 (14)
O2—H2A···O1	0.952 (15)	1.492 (16)	2.3992 (15)	157.5 (19)
C1—H1···O3ⁱ	0.93	2.49	3.3533 (17)	154
C16—H16B···O5ⁱⁱ	0.96	2.59	3.411 (2)	144

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

Acknowledgements

This project was supported by the Fundamental Research Funds for the Central Universities from the Ministry of Education of China (grant No. 11D-10544).

References

Bruker (2003). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Jessen, H. J. & Gademann, K. (2010). Nat. Prod. Rep. 27, 1168–1185. Web of Science CrossRef CAS PubMed Google Scholar
Rigby, J. H. & Burkhardt, F. J. (1986). J. Org. Chem. 51, 1374–1376. CrossRef CAS Web of Science Google Scholar
Rigby, J. H. & Qabar, M. (1989). J. Org. Chem. 54, 5852–5853. CrossRef CAS Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Tang, Y. M., Li, J. & Zhao, S. Y. (2011). Chin. J. Org. Chem. 31, 9–21. Google Scholar