(9S,13R,14R)-7,8-Didehydro-3,4,7-trimeth­oxy-17-methyl­morphinan-6-one

Li, Y.-F.; Qian, Y.; Yin, L.-H.; Lv, R.; Zhu, H.-J.

doi:10.1107/S1600536808040749

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 65| Part 4| April 2009| Page o689

doi:10.1107/S1600536808040749

Open

access

(9S,13R,14R)-7,8-Didehydro-3,4,7-trimethoxy-17-methylmorphinan-6-one

Yu-Feng Li,^a Yi Qian,^a Li-He Yin,^a Ran Lv ^a and Hong-Jun Zhu ^a ^*

^aDepartment of Applied Chemistry, College of Science, Nanjing University of Technology, Nanjing 210009, People's Republic of China
^*Correspondence e-mail: zhuhj@njut.edu.cn

(Received 23 October 2008; accepted 3 December 2008; online 6 March 2009)

The title compound, C₂₀H₂₅NO₄, was synthesized by a Mitsunobu reaction of sinomenine [(9S,13R,14R)-7,8-didehydro-4-hydroxy-3,7-dimethoxy-17-methylmorphinan-6-one] with methanol. The chiral centers were unchanged during the reaction. Intramolecular C—H⋯O hydrogen bonds result in the formation of six-membered rings.

Related literature

For the anti-inflammatory, antitussive and antiarrgythmic activities of sinomenine, see: Wang & Li (1965 ).

Experimental

Crystal data

C₂₀H₂₅NO₄
M_r = 343.41
Trigonal, P 3₂
a = 10.9590 (15) Å
c = 12.726 (3) Å
V = 1323.6 (4) Å³
Z = 3
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 298 K
0.40 × 0.30 × 0.30 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.965, T_max = 0.974
2008 measured reflections
1728 independent reflections
1281 reflections with I > 2σ(I)
R_int = 0.037
3 standard reflections every 200 reflections intensity decay: none

Refinement

R[F² > 2σ(F²)] = 0.070
wR(F²) = 0.208
S = 1.06
1728 reflections
226 parameters
44 restraints
H-atom parameters constrained
Δρ_max = 0.45 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C5—H5A⋯O1	0.97	2.23	2.853 (9)	121
C16—H16B⋯O1	0.97	2.53	3.102 (10)	118
C18—H18B⋯O2	0.96	2.14	2.812 (16)	126

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ); 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 global, I. DOI: 10.1107/S1600536808040749/hk2561sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808040749/hk2561Isup2.hkl

checkCIF report

Comment top

(9S,13R,14R)-7,8-Didehydro-3,4,7-trimethoxy-17-methylmorphinan-6-one (I) is a derivative of natural sinomenine. Sinomenine was reported possessing anti-inflammatory, antitussive and antiarrgythmic activities (Wang et al., 1965). We report here the crystal structure of I.

The molecular structure of I is shown in Fig. 1. The X-ray diffraction results show that I is a tetracyclic alkaloid with three chiral centers. The piperidine ring is in a chair conformation, and the other two six-membered aliphatic rings are in twisted boat conformation.

The intramolecular C—H···O hydrogen bonds(C5—H5A···O1, C16—H16A···O1 and C18—H18B···O2) result in the formation of six-membered rings, which may be effective to the stabilization of the crystals.

Related literature top

For the anti-inflammatory, antitussive and antiarrgythmic activities of sinomenine, see: Wang & Li (1965).

Experimental top

(9S,13R,14R)-7,8-Didehydro-4-hydroxy-3,7-dimethoxy-17-methylmorphinan-6-one (5 mmol, 1.65 g), triphenyl phosphine (10 mmol, 2.62 g) and absolute methanol (1 ml) were added in tetrahydrofuran(THF, 50 ml). Diethyl azodicarboxylate(10 mmol, 1.74 g) was added in dropwise during a period of 30 min. The solution was continuosly stirred for another 12 h. The solution was concentrated under reduced pressure and the residue was purified by column chromatography on silca gel(60–100 mesh) using ethyl acetate/triethylamine (V/V = 10:1). White product was obtained by crystallization from isopropyl ether. Crystals of the product suitable for X-ray diffraction were obtained by slow evaporation of methanol solution.

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo, 1995); 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. The molecular structure of (I), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. Hydrogen bonds are shown as dashed lines.

(9S,13R,14S)-7,8-didehydro-3,4,7-trimethoxy-N-methyl-morphinan-6-one top

Crystal data top

C₂₀H₂₅NO₄	D_x = 1.292 Mg m⁻³
M_r = 343.41	Mo Kα radiation, λ = 0.71073 Å
Trigonal, P3₂	Cell parameters from 25 reflections
Hall symbol: P 32	θ = 10–13°
a = 10.9590 (15) Å	µ = 0.09 mm⁻¹
c = 12.726 (3) Å	T = 298 K
V = 1323.6 (4) Å³	Block, colorless
Z = 3	0.40 × 0.30 × 0.30 mm
F(000) = 552

Data collection top

Enraf–Nonius CAD-4 diffractometer	1281 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.037
Graphite monochromator	θ_max = 26.0°, θ_min = 2.2°
ω/2θ scans	h = −13→6
Absorption correction: ψ scan (North et al., 1968)	k = 0→11
T_min = 0.965, T_max = 0.974	l = −15→15
2008 measured reflections	3 standard reflections every 200 reflections
1728 independent reflections	intensity decay: none

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)] = 0.070	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.208	H-atom parameters constrained
S = 1.06	w = 1/[σ²(F_o²) + (0.1178P)² + 0.4849P] where P = (F_o² + 2F_c²)/3
1728 reflections	(Δ/σ)_max = 0.005
226 parameters	Δρ_max = 0.45 e Å⁻³
44 restraints	Δρ_min = −0.22 e Å⁻³

Crystal data top

C₂₀H₂₅NO₄	Z = 3
M_r = 343.41	Mo Kα radiation
Trigonal, P3₂	µ = 0.09 mm⁻¹
a = 10.9590 (15) Å	T = 298 K
c = 12.726 (3) Å	0.40 × 0.30 × 0.30 mm
V = 1323.6 (4) Å³

Data collection top

Enraf–Nonius CAD-4 diffractometer	1281 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.037
T_min = 0.965, T_max = 0.974	3 standard reflections every 200 reflections
2008 measured reflections	intensity decay: none
1728 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.070	44 restraints
wR(F²) = 0.208	H-atom parameters constrained
S = 1.06	Δρ_max = 0.45 e Å⁻³
1728 reflections	Δρ_min = −0.22 e Å⁻³
226 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
O1	0.7890 (7)	0.2303 (6)	0.0383 (5)	0.0855 (17)
O2	0.8937 (7)	0.0744 (5)	0.1262 (6)	0.093 (2)
O3	1.2532 (6)	0.7232 (5)	−0.1456 (4)	0.0719 (13)
O4	1.0260 (6)	0.4750 (6)	−0.1870 (4)	0.0765 (15)
N	0.9014 (7)	0.6779 (6)	0.2458 (4)	0.0607 (14)
C18	0.7882 (16)	0.1603 (14)	−0.0423 (8)	0.123 (4)
H18A	0.6976	0.1188	−0.0757	0.185*
H18B	0.8071	0.0873	−0.0210	0.185*
H18C	0.8595	0.2222	−0.0909	0.185*
C17	0.9251 (11)	−0.0152 (9)	0.1821 (8)	0.093 (3)
H17A	0.8722	−0.1088	0.1540	0.139*
H17B	0.9009	−0.0159	0.2547	0.139*
H17C	1.0240	0.0172	0.1763	0.139*
C3	0.9567 (7)	0.2137 (7)	0.1507 (5)	0.0592 (16)
C4	0.9072 (7)	0.2945 (7)	0.0963 (5)	0.0563 (15)
C12	0.9634 (6)	0.4366 (6)	0.1177 (4)	0.0436 (12)
C11	1.0594 (6)	0.4957 (7)	0.1981 (4)	0.0470 (13)
C1	1.1056 (8)	0.4155 (8)	0.2521 (5)	0.0590 (17)
H1A	1.1723	0.4579	0.3051	0.071*
C2	1.0563 (8)	0.2771 (8)	0.2294 (6)	0.0653 (19)
H2A	1.0890	0.2259	0.2663	0.078*
C19	1.3723 (8)	0.8546 (9)	−0.1173 (7)	0.082 (2)
H19A	1.4485	0.8759	−0.1646	0.123*
H19B	1.4005	0.8490	−0.0468	0.123*
H19C	1.3480	0.9274	−0.1212	0.123*
C20	0.9242 (11)	0.7233 (10)	0.3554 (6)	0.085 (2)
H20A	0.9976	0.8201	0.3594	0.127*
H20B	0.9511	0.6659	0.3949	0.127*
H20C	0.8388	0.7138	0.3840	0.127*
C15	0.7923 (7)	0.5297 (7)	0.2337 (5)	0.0569 (16)
H15A	0.7056	0.5152	0.2655	0.068*
H15B	0.8213	0.4711	0.2709	0.068*
C16	0.7647 (6)	0.4843 (7)	0.1193 (5)	0.0531 (15)
H16A	0.7221	0.5323	0.0842	0.064*
H16B	0.6994	0.3837	0.1154	0.064*
C13	0.9034 (6)	0.5194 (6)	0.0638 (5)	0.0461 (13)
C5	0.8825 (7)	0.4990 (7)	−0.0559 (5)	0.0533 (14)
H5A	0.8155	0.4009	−0.0706	0.064*
H5B	0.8429	0.5550	−0.0819	0.064*
C6	1.0162 (7)	0.5401 (7)	−0.1131 (5)	0.0557 (15)
C7	1.1414 (7)	0.6762 (7)	−0.0771 (5)	0.0541 (14)
C8	1.1330 (7)	0.7371 (6)	0.0109 (5)	0.0532 (15)
H8A	1.2119	0.8200	0.0328	0.064*
C14	1.0026 (7)	0.6780 (6)	0.0759 (4)	0.0470 (13)
H14A	0.9502	0.7236	0.0519	0.056*
C9	1.0334 (7)	0.7134 (7)	0.1920 (5)	0.0549 (15)
H9A	1.0938	0.8159	0.1966	0.066*
C10	1.1204 (8)	0.6499 (7)	0.2307 (5)	0.0593 (16)
H10A	1.1262	0.6562	0.3067	0.071*
H10B	1.2153	0.7046	0.2031	0.071*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.090 (4)	0.069 (3)	0.099 (4)	0.040 (3)	−0.017 (3)	−0.012 (3)
O2	0.101 (4)	0.042 (3)	0.140 (5)	0.039 (3)	−0.018 (4)	0.016 (3)
O3	0.071 (3)	0.068 (3)	0.071 (3)	0.030 (3)	0.023 (2)	0.011 (2)
O4	0.077 (3)	0.081 (3)	0.075 (3)	0.042 (3)	−0.001 (3)	−0.024 (3)
N	0.077 (4)	0.066 (3)	0.053 (3)	0.046 (3)	0.007 (3)	0.001 (2)
C18	0.207 (13)	0.138 (9)	0.090 (7)	0.135 (10)	−0.005 (7)	−0.001 (7)
C17	0.112 (7)	0.062 (5)	0.126 (7)	0.060 (5)	0.041 (6)	0.043 (5)
C3	0.059 (4)	0.051 (3)	0.072 (4)	0.031 (3)	0.010 (3)	0.020 (3)
C4	0.058 (4)	0.041 (3)	0.069 (4)	0.024 (3)	0.001 (3)	0.014 (3)
C12	0.048 (3)	0.046 (3)	0.045 (3)	0.030 (3)	0.002 (2)	0.010 (2)
C11	0.056 (3)	0.055 (3)	0.042 (3)	0.037 (3)	−0.001 (3)	0.002 (2)
C1	0.067 (4)	0.085 (5)	0.049 (3)	0.056 (4)	−0.002 (3)	0.009 (3)
C2	0.069 (4)	0.073 (5)	0.077 (4)	0.053 (4)	0.006 (4)	0.021 (4)
C19	0.062 (5)	0.086 (6)	0.078 (5)	0.023 (4)	0.012 (4)	−0.008 (4)
C20	0.124 (7)	0.101 (6)	0.054 (4)	0.074 (6)	0.010 (4)	0.001 (4)
C15	0.061 (4)	0.062 (4)	0.064 (4)	0.042 (3)	0.010 (3)	0.009 (3)
C16	0.045 (3)	0.053 (3)	0.066 (4)	0.028 (3)	0.002 (3)	0.013 (3)
C13	0.047 (3)	0.043 (3)	0.054 (3)	0.027 (3)	−0.004 (3)	0.006 (2)
C5	0.062 (3)	0.046 (3)	0.060 (3)	0.034 (3)	−0.010 (3)	−0.002 (3)
C6	0.064 (4)	0.050 (3)	0.059 (3)	0.032 (3)	−0.002 (3)	0.000 (3)
C7	0.060 (3)	0.054 (3)	0.046 (3)	0.027 (3)	0.004 (3)	0.003 (3)
C8	0.058 (3)	0.045 (3)	0.054 (3)	0.024 (3)	0.003 (3)	0.003 (2)
C14	0.060 (4)	0.042 (3)	0.045 (3)	0.030 (3)	0.004 (3)	0.007 (2)
C9	0.065 (4)	0.052 (3)	0.052 (4)	0.033 (3)	−0.008 (3)	−0.003 (3)
C10	0.069 (4)	0.069 (4)	0.048 (3)	0.041 (4)	−0.019 (3)	−0.008 (3)

Geometric parameters (Å, º) top

O1—C18	1.278 (11)	C19—H19B	0.9600
O1—C4	1.344 (9)	C19—H19C	0.9600
O2—C3	1.360 (8)	C20—H20A	0.9600
O2—C17	1.388 (9)	C20—H20B	0.9600
O3—C7	1.377 (8)	C20—H20C	0.9600
O3—C19	1.424 (9)	C15—C16	1.520 (7)
O4—C6	1.217 (8)	C15—H15A	0.9700
N—C20	1.461 (10)	C15—H15B	0.9700
N—C9	1.466 (9)	C16—C13	1.541 (8)
N—C15	1.466 (9)	C16—H16A	0.9700
C18—H18A	0.9600	C16—H16B	0.9700
C18—H18B	0.9600	C13—C14	1.528 (8)
C18—H18C	0.9600	C13—C5	1.540 (9)
C17—H17A	0.9600	C5—C6	1.490 (10)
C17—H17B	0.9600	C5—H5A	0.9700
C17—H17C	0.9600	C5—H5B	0.9700
C3—C2	1.386 (10)	C6—C7	1.507 (9)
C3—C4	1.428 (8)	C7—C8	1.330 (9)
C4—C12	1.385 (9)	C8—C14	1.491 (9)
C12—C11	1.376 (8)	C8—H8A	0.9300
C12—C13	1.524 (7)	C14—C9	1.523 (8)
C11—C1	1.395 (8)	C14—H14A	0.9800
C11—C10	1.531 (9)	C9—C10	1.516 (9)
C1—C2	1.363 (10)	C9—H9A	0.9800
C1—H1A	0.9300	C10—H10A	0.9700
C2—H2A	0.9300	C10—H10B	0.9700
C19—H19A	0.9600

C18—O1—C4	118.1 (9)	C16—C15—H15A	109.1
C3—O2—C17	120.6 (7)	N—C15—H15B	109.1
C7—O3—C19	114.3 (6)	C16—C15—H15B	109.1
C20—N—C9	112.2 (6)	H15A—C15—H15B	107.9
C20—N—C15	112.5 (6)	C15—C16—C13	110.4 (5)
C9—N—C15	113.3 (5)	C15—C16—H16A	109.6
O1—C18—H18A	109.5	C13—C16—H16A	109.6
O1—C18—H18B	109.5	C15—C16—H16B	109.6
H18A—C18—H18B	109.5	C13—C16—H16B	109.6
O1—C18—H18C	109.5	H16A—C16—H16B	108.1
H18A—C18—H18C	109.5	C12—C13—C14	111.0 (5)
H18B—C18—H18C	109.5	C12—C13—C5	115.9 (5)
O2—C17—H17A	109.5	C14—C13—C5	103.5 (4)
O2—C17—H17B	109.5	C12—C13—C16	108.0 (5)
H17A—C17—H17B	109.5	C14—C13—C16	106.8 (5)
O2—C17—H17C	109.5	C5—C13—C16	111.2 (5)
H17A—C17—H17C	109.5	C6—C5—C13	112.7 (5)
H17B—C17—H17C	109.5	C6—C5—H5A	109.0
O2—C3—C2	124.0 (6)	C13—C5—H5A	109.0
O2—C3—C4	116.6 (6)	C6—C5—H5B	109.0
C2—C3—C4	119.2 (6)	C13—C5—H5B	109.0
O1—C4—C12	117.9 (5)	H5A—C5—H5B	107.8
O1—C4—C3	120.5 (6)	O4—C6—C5	124.2 (6)
C12—C4—C3	120.6 (6)	O4—C6—C7	120.8 (6)
C11—C12—C4	118.8 (5)	C5—C6—C7	115.0 (5)
C11—C12—C13	120.7 (5)	C8—C7—O3	128.1 (6)
C4—C12—C13	119.9 (5)	C8—C7—C6	119.7 (6)
C12—C11—C1	120.2 (6)	O3—C7—C6	112.2 (5)
C12—C11—C10	122.0 (5)	C7—C8—C14	122.8 (6)
C1—C11—C10	117.8 (5)	C7—C8—H8A	118.6
C2—C1—C11	122.1 (6)	C14—C8—H8A	118.6
C2—C1—H1A	119.0	C8—C14—C9	112.7 (5)
C11—C1—H1A	119.0	C8—C14—C13	114.8 (5)
C1—C2—C3	119.1 (6)	C9—C14—C13	109.2 (5)
C1—C2—H2A	120.5	C8—C14—H14A	106.5
C3—C2—H2A	120.5	C9—C14—H14A	106.5
O3—C19—H19A	109.5	C13—C14—H14A	106.5
O3—C19—H19B	109.5	N—C9—C10	119.4 (5)
H19A—C19—H19B	109.5	N—C9—C14	108.8 (5)
O3—C19—H19C	109.5	C10—C9—C14	108.0 (5)
H19A—C19—H19C	109.5	N—C9—H9A	106.7
H19B—C19—H19C	109.5	C10—C9—H9A	106.7
N—C20—H20A	109.5	C14—C9—H9A	106.7
N—C20—H20B	109.5	C9—C10—C11	113.0 (5)
H20A—C20—H20B	109.5	C9—C10—H10A	109.0
N—C20—H20C	109.5	C11—C10—H10A	109.0
H20A—C20—H20C	109.5	C9—C10—H10B	109.0
H20B—C20—H20C	109.5	C11—C10—H10B	109.0
N—C15—C16	112.4 (5)	H10A—C10—H10B	107.8
N—C15—H15A	109.1

C17—O2—C3—C2	1.2 (12)	C12—C13—C5—C6	−59.6 (7)
C17—O2—C3—C4	−173.7 (7)	C14—C13—C5—C6	62.2 (6)
C18—O1—C4—C12	127.8 (8)	C16—C13—C5—C6	176.6 (5)
C18—O1—C4—C3	−64.2 (11)	C13—C5—C6—O4	139.7 (7)
O2—C3—C4—O1	11.0 (10)	C13—C5—C6—C7	−43.8 (7)
C2—C3—C4—O1	−164.1 (7)	C19—O3—C7—C8	−1.0 (11)
O2—C3—C4—C12	178.7 (6)	C19—O3—C7—C6	177.5 (6)
C2—C3—C4—C12	3.6 (9)	O4—C6—C7—C8	−172.3 (7)
O1—C4—C12—C11	162.8 (6)	C5—C6—C7—C8	11.0 (8)
C3—C4—C12—C11	−5.2 (9)	O4—C6—C7—O3	9.1 (9)
O1—C4—C12—C13	−8.4 (9)	C5—C6—C7—O3	−167.6 (6)
C3—C4—C12—C13	−176.4 (6)	O3—C7—C8—C14	177.1 (6)
C4—C12—C11—C1	4.2 (9)	C6—C7—C8—C14	−1.3 (9)
C13—C12—C11—C1	175.3 (6)	C7—C8—C14—C9	150.3 (6)
C4—C12—C11—C10	−176.7 (6)	C7—C8—C14—C13	24.5 (9)
C13—C12—C11—C10	−5.6 (9)	C12—C13—C14—C8	73.0 (6)
C12—C11—C1—C2	−1.5 (10)	C5—C13—C14—C8	−52.0 (6)
C10—C11—C1—C2	179.3 (6)	C16—C13—C14—C8	−169.4 (5)
C11—C1—C2—C3	−0.2 (10)	C12—C13—C14—C9	−54.6 (6)
O2—C3—C2—C1	−175.6 (7)	C5—C13—C14—C9	−179.6 (5)
C4—C3—C2—C1	−0.8 (10)	C16—C13—C14—C9	62.9 (6)
C20—N—C15—C16	177.7 (6)	C20—N—C9—C10	62.0 (8)
C9—N—C15—C16	−53.7 (7)	C15—N—C9—C10	−66.7 (7)
N—C15—C16—C13	53.3 (6)	C20—N—C9—C14	−173.6 (5)
C11—C12—C13—C14	23.7 (7)	C15—N—C9—C14	57.7 (6)
C4—C12—C13—C14	−165.3 (5)	C8—C14—C9—N	168.2 (5)
C11—C12—C13—C5	141.4 (6)	C13—C14—C9—N	−63.0 (6)
C4—C12—C13—C5	−47.6 (8)	C8—C14—C9—C10	−61.0 (7)
C11—C12—C13—C16	−93.2 (6)	C13—C14—C9—C10	67.9 (7)
C4—C12—C13—C16	77.8 (7)	N—C9—C10—C11	76.5 (7)
C15—C16—C13—C12	62.0 (6)	C14—C9—C10—C11	−48.2 (7)
C15—C16—C13—C14	−57.5 (6)	C12—C11—C10—C9	18.3 (9)
C15—C16—C13—C5	−169.8 (5)	C1—C11—C10—C9	−162.5 (6)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5A···O1	0.97	2.23	2.853 (9)	121
C16—H16B···O1	0.97	2.53	3.102 (10)	118
C18—H18B···O2	0.96	2.14	2.812 (16)	126

Experimental details

Crystal data
Chemical formula	C₂₀H₂₅NO₄
M_r	343.41
Crystal system, space group	Trigonal, P3₂
Temperature (K)	298
a, c (Å)	10.9590 (15), 12.726 (3)
V (Å³)	1323.6 (4)
Z	3
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.40 × 0.30 × 0.30

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	ψ scan (North et al., 1968)
T_min, T_max	0.965, 0.974
No. of measured, independent and observed [I > 2σ(I)] reflections	2008, 1728, 1281
R_int	0.037
(sin θ/λ)_max (Å⁻¹)	0.616

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.070, 0.208, 1.06
No. of reflections	1728
No. of parameters	226
No. of restraints	44
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.45, −0.22

Computer programs: CAD-4 Software (Enraf–Nonius, 1989), XCAD4 (Harms & Wocadlo, 1995), 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
C5—H5A···O1	0.9700	2.2300	2.853 (9)	121.00
C16—H16B···O1	0.9700	2.5300	3.102 (10)	118.00
C18—H18B···O2	0.9600	2.1400	2.812 (16)	126.00

Acknowledgements

The authors thank the Center of Testing and Analysis, Nanjing University, for support.

References

Enraf–Nonius (1989). CAD-4 Software. Enraf–Nonius, Delft. The Netherlands. Google Scholar
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Google Scholar
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359. CrossRef IUCr Journals Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Wang, N. Q. & Li, Y. S. (1965). Acta Pharm. Sin. 12, 86–87. CAS Google Scholar