(1R,3S)-Methyl 6,7-dimeth­oxy-1-(4-meth­oxy­phen­yl)-1,2,3,4-tetra­hydro­isoquinoline-3-carboxyl­ate

Naicker, T.; Govender, T.; Kruger, H.G.; Maguire, G.E.M.

doi:10.1107/S1600536810044909

organic compounds

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ISSN: 2056-9890

Volume 66| Part 12| December 2010| Page o3105

https://doi.org/10.1107/S1600536810044909

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(1R,3S)-Methyl 6,7-dimethoxy-1-(4-methoxyphenyl)-1,2,3,4-tetrahydroisoquinoline-3-carboxylate

Tricia Naicker,^a Thavendran Govender,^b Hendrik G. Kruger ^a and Glenn E. M. Maguire ^a ^*

^aSchool of Chemistry, University of KwaZulu-Natal, Durban 4000, South Africa, and ^bSchool of Pharmacy and Pharmacology, University of KwaZulu-Natal, Durban 4000, South Africa
^*Correspondence e-mail: maguireg@ukzn.ac.za

(Received 8 September 2010; accepted 2 November 2010; online 6 November 2010)

The title compound, C₂₀H₂₃NO₅, is the third in a series of tetrahydoisoquinoline (TIQ) compounds that are precursors to novel chiral catalysts. The N-containing six-membered ring assumes a half-boat conformation. No hydrogen bonding is observed in the crystal structure.

Related literature

For related structures, see: Naicker et al. (2009 , 2010 ); Alberach et al. (2004 ). For the synthesis of the title compound, see: Aubry et al. (2006 ).

Experimental

Crystal data

C₂₀H₂₃NO₅
M_r = 357.39
Orthorhombic, P 2₁ 2₁ 2₁
a = 5.3719 (7) Å
b = 12.1726 (14) Å
c = 27.021 (3) Å
V = 1766.9 (4) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 173 K
0.20 × 0.12 × 0.12 mm

Data collection

Bruker Kappa DUO APEXII diffractometer
13619 measured reflections
2878 independent reflections
2538 reflections with I > 2σ(I)
R_int = 0.032

Refinement

R[F² > 2σ(F²)] = 0.036
wR(F²) = 0.090
S = 1.04
2878 reflections
239 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Data collection: APEX2 (Bruker, 2006 ); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536810044909/hg2711sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810044909/hg2711Isup2.hkl

checkCIF report

Comment top

The title compound was derived from commercially available L-DOPA and anisaldehyde. Diastereomers formed during the first step of the synthesis were separated to yield subsequent derivatives and the title compound with the stereochemistry as illustrated in Fig. 1. The title compound is the third report in a series of molecules containing a tetrahydroisoquinoline backbone and is a precursor to one of the molecules that we previously reported ((1R,3S)-methyl 2-benzyl-6,7-dimethoxy-1-phenyl-1,2,3,4-tetrahydroisoquinoline-3-carboxylate), (Naicker et al., 2009). The molecule has been reported previously and the absolute stereochemistry of the diastereomer was confirmed to be R,S at C4 and C2 positions respectively by proton NMR (Aubry et al., 2006).

There are a number of common features found in this structure and that of the the unprotected secondary amine system. First, the N-containing six membered ring assumes a half boat conformation. This differs from last report for the (1R,3S)-2-benzyl-6,7-dimethoxy-1-phenyl-1,2,3,4 tetrahydroisoquinolin-3-yl diphenylmethanol structure (Naicker et al., 2010) and previous reports by Alberach et al. (2004) and Aubry et al. (2006) where the heteroatomic ring adopted a half chair conformation. Second, given the presence of the secondary amine, ether and in this example ester functional groups, no hydrogen bonding is observed in any of the structures of this series, (see Fig. 2).

Related literature top

For related crystallographic structures, see: Naicker et al. (2009, 2010); Alberach et al. (2004). For synthesis of the title compound, see: Aubry et al. (2006).

Experimental top

A solution of the Cbz protected trans-6,7-dimethoxy-1-(4-methoxyphenyl)-TIQ methyl ester (1.0 g, 0.21 mmol) in THF (20 ml) was added to a suspension of activated 10 wt% Pd/C (500 mg) in dry MeOH (20 ml). The mixture was connected to a hydrogen source at one atmosphere and stirred at room temperature for 1 h. Completion of the reaction was monitored through TLC in hexane/ethyl acetate (50/50, R_f = 0.6). The Pd/C was filtered through a Celite pad and washed with methanol (20 ml). The filtrate was evaporated under reduced pressure affording the crude amino ester, which was purified by column chromatography using ethyl acetate/hexane (50:50) as the eluent to yield pure title compound (0.70 g, 93%) as a yellow solid. m.p. = 392–393 K. Crystals suitable for X-ray diffraction were obtained by slow evaporation of the title compound in MeOH at room temperature.

¹H NMR (600 MHz, CdCl₃, d, p.p.m.): 1.58 (broad s, 1H), 2.99 (dd, 1H), 3.09 (dd, 1H), 3.60 (s, 3H), 3.66 (s, 3H) 3.67(s, 3H), 3.78 (m, 1H), 3.88 (s, 3H), 5.23 (s, 1H), 6.30(s, 1H), 6.61 (s, 1H), 6.82 (d, 2H), 7.09 (d, 2H).

IR: 2946 (w), 1700 (w), 1507 (s), 1223 (vs), 832 (s), 563 (w)

Structure description top

For related crystallographic structures, see: Naicker et al. (2009, 2010); Alberach et al. (2004). For synthesis of the title compound, see: Aubry et al. (2006).

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. The title compound (all H atoms omitted for clarity). All non-H atoms are shown as ellipsoids with probability level of 50%.
	Fig. 2. Projection viewed along [010].

(1R,3S)-Methyl 6,7-dimethoxy-1-(4-methoxyphenyl)-1,2,3,4-tetrahydroisoquinoline-3-carboxylate top

Crystal data top

C₂₀H₂₃NO₅	F(000) = 760
M_r = 357.39	D_x = 1.344 Mg m⁻³
Orthorhombic, P2₁2₁2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 13619 reflections
a = 5.3719 (7) Å	θ = 2.3–29.6°
b = 12.1726 (14) Å	µ = 0.10 mm⁻¹
c = 27.021 (3) Å	T = 173 K
V = 1766.9 (4) Å³	Needle, colourless
Z = 4	0.20 × 0.12 × 0.12 mm

Data collection top

Bruker Kappa DUO APEXII diffractometer	2538 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.032
Graphite monochromator	θ_max = 29.6°, θ_min = 2.3°
0.5° φ scans and ω scans	h = −7→7
13619 measured reflections	k = −16→16
2878 independent reflections	l = −26→37

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)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.090	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ²(F_o²) + (0.0435P)² + 0.3587P] where P = (F_o² + 2F_c²)/3
2878 reflections	(Δ/σ)_max = 0.001
239 parameters	Δρ_max = 0.26 e Å⁻³
1 restraint	Δρ_min = −0.18 e Å⁻³

Crystal data top

C₂₀H₂₃NO₅	V = 1766.9 (4) Å³
M_r = 357.39	Z = 4
Orthorhombic, P2₁2₁2₁	Mo Kα radiation
a = 5.3719 (7) Å	µ = 0.10 mm⁻¹
b = 12.1726 (14) Å	T = 173 K
c = 27.021 (3) Å	0.20 × 0.12 × 0.12 mm

Data collection top

Bruker Kappa DUO APEXII diffractometer	2538 reflections with I > 2σ(I)
13619 measured reflections	R_int = 0.032
2878 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.036	1 restraint
wR(F²) = 0.090	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	Δρ_max = 0.26 e Å⁻³
2878 reflections	Δρ_min = −0.18 e Å⁻³
239 parameters

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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	0.6521 (3)	0.82927 (10)	0.91879 (5)	0.0334 (3)
O2	0.3315 (3)	0.91415 (10)	0.85890 (5)	0.0351 (3)
O3	0.3734 (3)	0.44954 (13)	0.76583 (6)	0.0498 (4)
O4	0.2473 (3)	0.28121 (11)	0.78678 (5)	0.0378 (3)
O5	0.4011 (3)	0.34146 (11)	1.09674 (5)	0.0307 (3)
N1	0.0808 (3)	0.40422 (12)	0.87542 (5)	0.0253 (3)
H1N	0.078 (4)	0.3258 (5)	0.8806 (7)	0.031 (5)*
C1	0.3147 (3)	0.45361 (13)	0.89317 (6)	0.0224 (3)
H1	0.4574	0.4190	0.8752	0.027*
C2	0.3126 (3)	0.57639 (13)	0.88213 (6)	0.0211 (3)
C3	0.4841 (3)	0.64470 (14)	0.90671 (6)	0.0229 (3)
H3	0.5967	0.6136	0.9299	0.027*
C4	0.4912 (3)	0.75648 (14)	0.89759 (6)	0.0242 (3)
C5	0.3187 (4)	0.80245 (13)	0.86413 (6)	0.0250 (3)
C6	0.1543 (3)	0.73469 (14)	0.83937 (6)	0.0253 (3)
H6	0.0407	0.7657	0.8164	0.030*
C7	0.1519 (3)	0.62062 (14)	0.84759 (6)	0.0231 (3)
C8	−0.0280 (3)	0.55050 (15)	0.81826 (7)	0.0269 (4)
H8A	−0.0184	0.5713	0.7829	0.032*
H8B	−0.1997	0.5652	0.8298	0.032*
C9	0.0265 (3)	0.42813 (14)	0.82338 (6)	0.0264 (4)
H9	−0.1279	0.3871	0.8141	0.032*
C10	0.2348 (4)	0.39131 (15)	0.78851 (6)	0.0276 (4)
C11	0.4358 (4)	0.23681 (18)	0.75419 (8)	0.0383 (5)
H11A	0.4304	0.1564	0.7553	0.057*
H11B	0.6003	0.2623	0.7649	0.057*
H11C	0.4044	0.2617	0.7203	0.057*
C12	0.3392 (3)	0.42874 (12)	0.94812 (6)	0.0216 (3)
C13	0.5433 (3)	0.37117 (13)	0.96620 (6)	0.0239 (3)
H13	0.6727	0.3501	0.9442	0.029*
C14	0.5606 (3)	0.34403 (14)	1.01604 (7)	0.0256 (3)
H14	0.7007	0.3045	1.0280	0.031*
C15	0.3716 (3)	0.37499 (13)	1.04827 (6)	0.0238 (3)
C16	0.1682 (3)	0.43478 (13)	1.03116 (6)	0.0250 (3)
H16	0.0406	0.4574	1.0533	0.030*
C17	0.1551 (3)	0.46090 (13)	0.98113 (6)	0.0245 (3)
H17	0.0167	0.5017	0.9692	0.029*
C18	0.1949 (4)	0.35863 (18)	1.12932 (7)	0.0399 (5)
H18A	0.2374	0.3319	1.1625	0.060*
H18B	0.0496	0.3185	1.1169	0.060*
H18C	0.1563	0.4372	1.1309	0.060*
C19	0.8323 (4)	0.78695 (16)	0.95244 (7)	0.0317 (4)
H19A	0.9354	0.8473	0.9650	0.047*
H19B	0.9380	0.7334	0.9353	0.047*
H19C	0.7474	0.7510	0.9802	0.047*
C20	0.1569 (4)	0.96322 (17)	0.82600 (8)	0.0419 (5)
H20A	0.1835	1.0429	0.8252	0.063*
H20B	−0.0125	0.9477	0.8375	0.063*
H20C	0.1797	0.9329	0.7927	0.063*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0349 (7)	0.0253 (6)	0.0399 (7)	−0.0042 (6)	−0.0127 (6)	−0.0019 (5)
O2	0.0433 (8)	0.0212 (6)	0.0409 (8)	−0.0014 (6)	−0.0095 (7)	0.0042 (5)
O3	0.0537 (10)	0.0375 (8)	0.0581 (10)	−0.0089 (8)	0.0274 (9)	−0.0036 (7)
O4	0.0463 (8)	0.0301 (7)	0.0370 (7)	−0.0025 (6)	0.0121 (7)	−0.0065 (6)
O5	0.0360 (7)	0.0309 (6)	0.0252 (6)	0.0054 (6)	0.0012 (5)	0.0018 (5)
N1	0.0265 (7)	0.0241 (7)	0.0253 (7)	−0.0065 (6)	0.0018 (6)	−0.0012 (6)
C1	0.0226 (7)	0.0205 (7)	0.0242 (7)	−0.0020 (6)	0.0033 (6)	−0.0014 (6)
C2	0.0214 (7)	0.0201 (7)	0.0218 (7)	−0.0015 (6)	0.0032 (6)	−0.0004 (6)
C3	0.0221 (7)	0.0237 (7)	0.0229 (7)	0.0002 (6)	−0.0005 (6)	0.0009 (6)
C4	0.0246 (8)	0.0236 (7)	0.0246 (8)	−0.0022 (7)	−0.0007 (7)	−0.0023 (6)
C5	0.0292 (8)	0.0207 (7)	0.0252 (8)	−0.0003 (7)	0.0020 (7)	0.0014 (6)
C6	0.0256 (8)	0.0268 (8)	0.0235 (8)	0.0008 (7)	−0.0023 (7)	0.0023 (6)
C7	0.0229 (7)	0.0254 (7)	0.0211 (7)	−0.0019 (7)	0.0015 (7)	−0.0027 (6)
C8	0.0242 (8)	0.0296 (8)	0.0269 (8)	−0.0021 (7)	−0.0041 (7)	−0.0024 (7)
C9	0.0256 (8)	0.0276 (8)	0.0261 (8)	−0.0063 (7)	0.0012 (7)	−0.0034 (7)
C10	0.0302 (9)	0.0302 (9)	0.0223 (8)	−0.0047 (7)	−0.0004 (7)	−0.0057 (7)
C11	0.0400 (11)	0.0407 (11)	0.0342 (10)	0.0036 (9)	0.0033 (9)	−0.0115 (9)
C12	0.0226 (7)	0.0175 (7)	0.0248 (8)	−0.0022 (6)	0.0006 (7)	−0.0006 (6)
C13	0.0198 (7)	0.0214 (7)	0.0304 (8)	0.0000 (6)	0.0042 (7)	−0.0027 (6)
C14	0.0214 (7)	0.0225 (7)	0.0329 (9)	0.0021 (6)	−0.0017 (7)	0.0004 (7)
C15	0.0281 (8)	0.0185 (7)	0.0247 (8)	−0.0027 (6)	−0.0004 (7)	−0.0006 (6)
C16	0.0252 (7)	0.0220 (7)	0.0278 (8)	0.0027 (7)	0.0041 (7)	−0.0028 (6)
C17	0.0235 (7)	0.0211 (7)	0.0289 (8)	0.0036 (7)	0.0012 (7)	0.0006 (6)
C18	0.0469 (12)	0.0432 (11)	0.0296 (9)	0.0033 (10)	0.0082 (9)	0.0042 (8)
C19	0.0302 (9)	0.0348 (9)	0.0300 (9)	−0.0043 (8)	−0.0062 (8)	−0.0030 (7)
C20	0.0488 (12)	0.0272 (9)	0.0498 (12)	0.0069 (10)	−0.0084 (11)	0.0058 (8)

Geometric parameters (Å, º) top

O1—C4	1.364 (2)	C8—H8B	0.9900
O1—C19	1.425 (2)	C9—C10	1.530 (3)
O2—C5	1.369 (2)	C9—H9	1.0000
O2—C20	1.424 (2)	C11—H11A	0.9800
O3—C10	1.197 (2)	C11—H11B	0.9800
O4—C10	1.343 (2)	C11—H11C	0.9800
O4—C11	1.446 (2)	C12—C17	1.388 (2)
O5—C15	1.381 (2)	C12—C13	1.390 (2)
O5—C18	1.430 (2)	C13—C14	1.390 (2)
N1—C9	1.465 (2)	C13—H13	0.9500
N1—C1	1.473 (2)	C14—C15	1.390 (2)
N1—H1N	0.965 (5)	C14—H14	0.9500
C1—C12	1.521 (2)	C15—C16	1.392 (2)
C1—C2	1.524 (2)	C16—C17	1.391 (2)
C1—H1	1.0000	C16—H16	0.9500
C2—C7	1.381 (2)	C17—H17	0.9500
C2—C3	1.407 (2)	C18—H18A	0.9800
C3—C4	1.383 (2)	C18—H18B	0.9800
C3—H3	0.9500	C18—H18C	0.9800
C4—C5	1.410 (2)	C19—H19A	0.9800
C5—C6	1.381 (2)	C19—H19B	0.9800
C6—C7	1.406 (2)	C19—H19C	0.9800
C6—H6	0.9500	C20—H20A	0.9800
C7—C8	1.514 (2)	C20—H20B	0.9800
C8—C9	1.524 (3)	C20—H20C	0.9800
C8—H8A	0.9900

C4—O1—C19	117.63 (14)	O3—C10—C9	126.64 (17)
C5—O2—C20	116.62 (16)	O4—C10—C9	110.53 (15)
C10—O4—C11	115.43 (16)	O4—C11—H11A	109.5
C15—O5—C18	116.85 (15)	O4—C11—H11B	109.5
C9—N1—C1	113.65 (13)	H11A—C11—H11B	109.5
C9—N1—H1N	109.5 (12)	O4—C11—H11C	109.5
C1—N1—H1N	111.7 (13)	H11A—C11—H11C	109.5
N1—C1—C12	108.07 (13)	H11B—C11—H11C	109.5
N1—C1—C2	109.28 (14)	C17—C12—C13	118.58 (15)
C12—C1—C2	112.76 (13)	C17—C12—C1	120.63 (15)
N1—C1—H1	108.9	C13—C12—C1	120.77 (15)
C12—C1—H1	108.9	C14—C13—C12	120.87 (16)
C2—C1—H1	108.9	C14—C13—H13	119.6
C7—C2—C3	119.86 (15)	C12—C13—H13	119.6
C7—C2—C1	121.29 (15)	C15—C14—C13	119.62 (16)
C3—C2—C1	118.82 (15)	C15—C14—H14	120.2
C4—C3—C2	121.00 (16)	C13—C14—H14	120.2
C4—C3—H3	119.5	O5—C15—C14	115.50 (16)
C2—C3—H3	119.5	O5—C15—C16	124.03 (16)
O1—C4—C3	125.56 (16)	C14—C15—C16	120.46 (16)
O1—C4—C5	115.32 (15)	C17—C16—C15	118.84 (16)
C3—C4—C5	119.11 (16)	C17—C16—H16	120.6
O2—C5—C6	125.13 (16)	C15—C16—H16	120.6
O2—C5—C4	115.30 (16)	C12—C17—C16	121.60 (16)
C6—C5—C4	119.57 (15)	C12—C17—H17	119.2
C5—C6—C7	121.27 (16)	C16—C17—H17	119.2
C5—C6—H6	119.4	O5—C18—H18A	109.5
C7—C6—H6	119.4	O5—C18—H18B	109.5
C2—C7—C6	119.08 (16)	H18A—C18—H18B	109.5
C2—C7—C8	122.23 (15)	O5—C18—H18C	109.5
C6—C7—C8	118.69 (16)	H18A—C18—H18C	109.5
C7—C8—C9	112.38 (15)	H18B—C18—H18C	109.5
C7—C8—H8A	109.1	O1—C19—H19A	109.5
C9—C8—H8A	109.1	O1—C19—H19B	109.5
C7—C8—H8B	109.1	H19A—C19—H19B	109.5
C9—C8—H8B	109.1	O1—C19—H19C	109.5
H8A—C8—H8B	107.9	H19A—C19—H19C	109.5
N1—C9—C8	108.63 (14)	H19B—C19—H19C	109.5
N1—C9—C10	112.79 (15)	O2—C20—H20A	109.5
C8—C9—C10	111.78 (15)	O2—C20—H20B	109.5
N1—C9—H9	107.8	H20A—C20—H20B	109.5
C8—C9—H9	107.8	O2—C20—H20C	109.5
C10—C9—H9	107.8	H20A—C20—H20C	109.5
O3—C10—O4	122.83 (18)	H20B—C20—H20C	109.5

C9—N1—C1—C12	176.36 (14)	C6—C7—C8—C9	168.41 (16)
C9—N1—C1—C2	53.33 (17)	C1—N1—C9—C8	−67.42 (18)
N1—C1—C2—C7	−18.3 (2)	C1—N1—C9—C10	57.07 (19)
C12—C1—C2—C7	−138.55 (16)	C7—C8—C9—N1	43.2 (2)
N1—C1—C2—C3	163.71 (14)	C7—C8—C9—C10	−81.93 (18)
C12—C1—C2—C3	43.5 (2)	C11—O4—C10—O3	−1.9 (3)
C7—C2—C3—C4	1.4 (2)	C11—O4—C10—C9	179.03 (15)
C1—C2—C3—C4	179.36 (15)	N1—C9—C10—O3	−110.1 (2)
C19—O1—C4—C3	1.4 (3)	C8—C9—C10—O3	12.7 (3)
C19—O1—C4—C5	−179.25 (15)	N1—C9—C10—O4	68.92 (19)
C2—C3—C4—O1	−178.92 (16)	C8—C9—C10—O4	−168.34 (16)
C2—C3—C4—C5	1.8 (3)	N1—C1—C12—C17	−57.33 (19)
C20—O2—C5—C6	1.4 (3)	C2—C1—C12—C17	63.6 (2)
C20—O2—C5—C4	−178.97 (16)	N1—C1—C12—C13	121.18 (16)
O1—C4—C5—O2	−2.1 (2)	C2—C1—C12—C13	−117.93 (17)
C3—C4—C5—O2	177.27 (16)	C17—C12—C13—C14	1.5 (2)
O1—C4—C5—C6	177.55 (16)	C1—C12—C13—C14	−177.06 (15)
C3—C4—C5—C6	−3.1 (3)	C12—C13—C14—C15	−0.1 (3)
O2—C5—C6—C7	−179.09 (17)	C18—O5—C15—C14	−171.63 (16)
C4—C5—C6—C7	1.3 (3)	C18—O5—C15—C16	7.7 (2)
C3—C2—C7—C6	−3.2 (2)	C13—C14—C15—O5	178.05 (15)
C1—C2—C7—C6	178.92 (15)	C13—C14—C15—C16	−1.3 (2)
C3—C2—C7—C8	177.06 (15)	O5—C15—C16—C17	−177.95 (16)
C1—C2—C7—C8	−0.9 (2)	C14—C15—C16—C17	1.3 (2)
C5—C6—C7—C2	1.9 (3)	C13—C12—C17—C16	−1.4 (2)
C5—C6—C7—C8	−178.36 (16)	C1—C12—C17—C16	177.10 (15)
C2—C7—C8—C9	−11.8 (2)	C15—C16—C17—C12	0.0 (3)

Experimental details

Crystal data
Chemical formula	C₂₀H₂₃NO₅
M_r	357.39
Crystal system, space group	Orthorhombic, P2₁2₁2₁
Temperature (K)	173
a, b, c (Å)	5.3719 (7), 12.1726 (14), 27.021 (3)
V (Å³)	1766.9 (4)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.20 × 0.12 × 0.12

Data collection
Diffractometer	Bruker Kappa DUO APEXII
Absorption correction	–
No. of measured, independent and observed [I > 2σ(I)] reflections	13619, 2878, 2538
R_int	0.032
(sin θ/λ)_max (Å⁻¹)	0.694

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.036, 0.090, 1.04
No. of reflections	2878
No. of parameters	239
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)	0.26, −0.18

Computer programs: APEX2 (Bruker, 2006), SAINT (Bruker, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), OLEX2 (Dolomanov et al., 2009).

Acknowledgements

The authors thank Dr Hong Su of the University of Capetown for the data collection and structure refinement.

References

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