2-Ethyl-8-methoxy­methyl-4-oxo-4H-chromen-7-yl (1S,4R)-4,7,7-trimethyl-3-oxo-2-oxabicyclo­[2.2.1]heptane-1-carboxyl­ate

Qiu, Y.; Chen, Y.; Xia, P.

doi:10.1107/S1600536810018921

organic compounds

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ISSN: 2056-9890

Volume 66| Part 6| June 2010| Page o1459

https://doi.org/10.1107/S1600536810018921

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2-Ethyl-8-methoxymethyl-4-oxo-4H-chromen-7-yl (1S,4R)-4,7,7-trimethyl-3-oxo-2-oxabicyclo[2.2.1]heptane-1-carboxylate

Ya Qiu,^a Ying Chen ^a and Peng Xia ^a ^*

^aDepartment of Medicinal Chemistry, School of Pharmacy, Fudan University, Shanghai 201203, People's Republic of China
^*Correspondence e-mail: pxia@fudan.edu.cn

(Received 26 April 2010; accepted 20 May 2010; online 26 May 2010)

The title compound C₂₃H₂₆O₇, was prepared by esterification of 2-ethyl-7-hydroxy-8-methoxymethyl-4H-chromen-4-one with (S)-(−)-camphanic chloride. The two rings of the chromone system are coplanar, making a dihedral angle of 1.99 (19)°, and the camphanoyl unit substituted at 7-O retains the original bicyclo[2.2.1]heptane conformation of the starting reagent.

Related literature

For background to 3′R,4′R-Di-O-(−)-camphanoyl-2′,2′-dimethyldihydropyrano[2,3-f]chromone (DCP) analogues as potent anti-HIV agents, see: Yu et al. (2004 ).

Experimental

Crystal data

C₂₃H₂₆O₇
M_r = 414.44
Monoclinic, P 2₁
a = 7.632 (3) Å
b = 14.159 (6) Å
c = 10.579 (4) Å
β = 109.240 (5)°
V = 1079.3 (8) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 K
0.22 × 0.12 × 0.05 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2000 ) T_min = 0.980, T_max = 0.995
4560 measured reflections
2016 independent reflections
1713 reflections with I > 2σ(I)
R_int = 0.056

Refinement

R[F² > 2σ(F²)] = 0.046
wR(F²) = 0.120
S = 0.96
2016 reflections
277 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); 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: https://doi.org/10.1107/S1600536810018921/bh2283sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810018921/bh2283Isup2.hkl

checkCIF report

Comment top

3'R,4'R-Di-O-(-)-camphanoyl-2',2'-dimethyldihydropyrano[2,3-f]chromone(DCP) analogues were potent anti-HIV agents (Yu et al. 2004). However, development of DCP analogues as effective anti-AIDS drugs has been hindered by problems of low water solubility and bioavailability. Therefore, we designed and synthesized a series of simplified DCP analogues. As one of the target compounds, the crystal structure of the title compound was reported here.

Fig.1 shows the molecular structure of the title compound, the two rings of chromone are planar and the camphanoyl unit substituted at 7-O retains its original bicyclo[2.2.1]heptane conformation and configuration with the chiralities of C16=S and C19=R in the purchased (S)-(-)-camphanic chloride reagent from Aldrich Company.

Related literature top

3'R,4'R-Di-O-(-)-camphanoyl-2',2'-dimethyldihydropyrano[2,3-f]chromone (DCP) analogues are potent anti-HIV agents, see: Yu et al. (2004).

Experimental top

The title compound was synthesized by the esterification of 2-ethyl-7-hydroxy-8-(methoxymethyl)-4H-chromen-4-one with (S)-(-)-camphanic chloride, which was purchased from Aldrich Company. 2-Ethyl-7-hydroxy-8-(methoxymethyl)-4H-chromen-4-one (250 mg, 1.07 mmol), (S)-(-)-camphanic chloride (255 mg, 1.17 mmol) and DMAP (156 mg, 1.28 mmol) were stirred in CH₂Cl₂ (8 ml) for 5 hours at room temperature. The mixture was concentrated and the residue was purified by chromatography on silica gel column with petroleum ether/EtOAc (4:1) as eluent, to afford the pure title compound, which was recrystallized from ethyl acetate to give colorless crystals for the single-crystal X-ray diffraction analysis. Yield: 52.5%.

Structure description top

3'R,4'R-Di-O-(-)-camphanoyl-2',2'-dimethyldihydropyrano[2,3-f]chromone (DCP) analogues are potent anti-HIV agents, see: Yu et al. (2004).

Computing details top

Data collection: SMART (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); 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 the title compound showing displacement ellipsoids at the 50% probability level. H atoms are presented as small spheres of arbitrary radius.

2-Ethyl-8-methoxymethyl-4-oxo-4H-chromen-7-yl (1S,4R)-4,7,7-trimethyl-3-oxo-2-oxabicyclo[2.2.1]heptane- 1-carboxylate top

Crystal data top

C₂₃H₂₆O₇	F(000) = 440
M_r = 414.44	D_x = 1.275 Mg m⁻³
Monoclinic, P2₁	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2yb	Cell parameters from 755 reflections
a = 7.632 (3) Å	θ = 2.5–24.2°
b = 14.159 (6) Å	µ = 0.09 mm⁻¹
c = 10.579 (4) Å	T = 293 K
β = 109.240 (5)°	Block, colourless
V = 1079.3 (8) Å³	0.22 × 0.12 × 0.05 mm
Z = 2

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	2016 independent reflections
Radiation source: fine-focus sealed tube	1713 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.056
φ and ω scans	θ_max = 25.2°, θ_min = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −8→9
T_min = 0.980, T_max = 0.995	k = −16→16
4560 measured reflections	l = −10→12

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)] = 0.046	H-atom parameters constrained
wR(F²) = 0.120	w = 1/[σ²(F_o²) + (0.0832P)²] where P = (F_o² + 2F_c²)/3
S = 0.96	(Δ/σ)_max < 0.001
2016 reflections	Δρ_max = 0.22 e Å⁻³
277 parameters	Δρ_min = −0.22 e Å⁻³
1 restraint	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
0 constraints	Extinction coefficient: 0.013 (4)
Primary atom site location: structure-invariant direct methods

Crystal data top

C₂₃H₂₆O₇	V = 1079.3 (8) Å³
M_r = 414.44	Z = 2
Monoclinic, P2₁	Mo Kα radiation
a = 7.632 (3) Å	µ = 0.09 mm⁻¹
b = 14.159 (6) Å	T = 293 K
c = 10.579 (4) Å	0.22 × 0.12 × 0.05 mm
β = 109.240 (5)°

Data collection top

Bruker SMART APEX CCD area-detector diffractometer	2016 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2000)	1713 reflections with I > 2σ(I)
T_min = 0.980, T_max = 0.995	R_int = 0.056
4560 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.046	1 restraint
wR(F²) = 0.120	H-atom parameters constrained
S = 0.96	Δρ_max = 0.22 e Å⁻³
2016 reflections	Δρ_min = −0.22 e Å⁻³
277 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	−0.1007 (3)	1.16766 (13)	0.3383 (2)	0.0443 (5)
C2	−0.0842 (5)	1.2628 (2)	0.3643 (3)	0.0460 (8)
C3	0.0805 (5)	1.3053 (2)	0.4130 (3)	0.0510 (8)
H3	0.0838	1.3703	0.4260	0.061*
C4	0.2530 (5)	1.2546 (2)	0.4464 (3)	0.0512 (8)
C4A	0.2332 (5)	1.1529 (2)	0.4138 (3)	0.0442 (7)
C5	0.3855 (5)	1.0927 (2)	0.4357 (4)	0.0520 (8)
H5	0.5048	1.1176	0.4683	0.062*
C6	0.3629 (5)	0.9984 (2)	0.4103 (3)	0.0499 (8)
H6	0.4650	0.9587	0.4267	0.060*
C7	0.1816 (5)	0.9628 (2)	0.3586 (3)	0.0428 (8)
C8	0.0253 (4)	1.0176 (2)	0.3351 (3)	0.0384 (7)
C8A	0.0561 (4)	1.1149 (2)	0.3633 (3)	0.0392 (7)
O9	0.1590 (3)	0.86439 (13)	0.3419 (2)	0.0448 (6)
O10	0.4071 (4)	1.29131 (18)	0.4995 (3)	0.0788 (9)
C11	−0.2707 (5)	1.3072 (3)	0.3325 (4)	0.0577 (9)
H11A	−0.2553	1.3752	0.3397	0.069*
H11B	−0.3252	1.2873	0.3990	0.069*
C12	−0.4034 (7)	1.2838 (4)	0.1956 (5)	0.0941 (16)
H12A	−0.3525	1.3048	0.1288	0.141*
H12B	−0.5198	1.3149	0.1827	0.141*
H12C	−0.4225	1.2167	0.1881	0.141*
C13	−0.1664 (4)	0.9791 (2)	0.2854 (3)	0.0443 (7)
H13A	−0.1648	0.9127	0.3086	0.053*
H13B	−0.2439	1.0123	0.3274	0.053*
O14	−0.2395 (3)	0.9897 (2)	0.1462 (2)	0.0717 (9)
C15	−0.4332 (6)	0.9722 (5)	0.0981 (5)	0.1000 (19)
H15A	−0.4557	0.9064	0.1084	0.150*
H15B	−0.4824	0.9890	0.0051	0.150*
H15C	−0.4928	1.0093	0.1481	0.150*
C16	0.1813 (4)	0.7210 (2)	0.2305 (3)	0.0403 (7)
O17	0.1708 (3)	0.68204 (13)	0.35476 (19)	0.0431 (5)
C18	0.0979 (5)	0.5937 (2)	0.3243 (3)	0.0497 (8)
C19	0.0611 (6)	0.5780 (2)	0.1774 (3)	0.0537 (9)
C20	0.2585 (7)	0.5689 (3)	0.1692 (4)	0.0729 (12)
H20A	0.2545	0.5498	0.0802	0.087*
H20B	0.3312	0.5234	0.2338	0.087*
C21	0.3406 (6)	0.6700 (3)	0.2025 (4)	0.0635 (10)
H21A	0.4521	0.6700	0.2804	0.076*
H21B	0.3679	0.6979	0.1272	0.076*
C22	0.0037 (5)	0.6798 (2)	0.1255 (3)	0.0510 (8)
O23	0.0780 (5)	0.54276 (18)	0.4081 (3)	0.0817 (10)
C24	−0.0689 (8)	0.4966 (3)	0.1177 (5)	0.0948 (16)
H24A	−0.0131	0.4384	0.1579	0.142*
H24B	−0.0920	0.4941	0.0229	0.142*
H24C	−0.1840	0.5057	0.1344	0.142*
C25	−0.1748 (6)	0.7137 (4)	0.1453 (5)	0.0755 (12)
H25A	−0.2779	0.6786	0.0878	0.113*
H25B	−0.1921	0.7797	0.1238	0.113*
H25C	−0.1669	0.7042	0.2369	0.113*
C26	−0.0086 (8)	0.6956 (3)	−0.0214 (4)	0.0833 (14)
H26A	−0.1135	0.6619	−0.0794	0.125*
H26B	0.1028	0.6729	−0.0344	0.125*
H26C	−0.0228	0.7618	−0.0419	0.125*
C27	0.1974 (5)	0.8265 (2)	0.2372 (3)	0.0457 (8)
O28	0.2358 (5)	0.87123 (19)	0.1549 (3)	0.0764 (9)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0449 (12)	0.0358 (11)	0.0486 (12)	0.0011 (10)	0.0106 (10)	−0.0002 (9)
C2	0.057 (2)	0.0398 (17)	0.0396 (16)	0.0053 (16)	0.0137 (14)	0.0023 (13)
C3	0.063 (2)	0.0355 (17)	0.053 (2)	−0.0031 (15)	0.0165 (17)	−0.0045 (13)
C4	0.051 (2)	0.0424 (19)	0.054 (2)	−0.0078 (15)	0.0098 (15)	−0.0022 (15)
C4A	0.049 (2)	0.0363 (16)	0.0424 (17)	−0.0044 (14)	0.0083 (14)	−0.0008 (13)
C5	0.0417 (18)	0.0453 (19)	0.059 (2)	−0.0062 (15)	0.0033 (15)	0.0011 (16)
C6	0.0422 (18)	0.0421 (18)	0.0583 (19)	0.0065 (15)	0.0067 (15)	0.0036 (15)
C7	0.053 (2)	0.0324 (16)	0.0409 (16)	−0.0031 (14)	0.0127 (14)	0.0044 (12)
C8	0.0441 (17)	0.0369 (16)	0.0331 (14)	−0.0060 (13)	0.0111 (12)	0.0006 (11)
C8A	0.0431 (17)	0.0388 (17)	0.0331 (15)	0.0015 (14)	0.0091 (12)	0.0032 (12)
O9	0.0593 (15)	0.0297 (11)	0.0472 (12)	−0.0018 (10)	0.0199 (11)	0.0027 (9)
O10	0.0570 (17)	0.0515 (16)	0.114 (2)	−0.0144 (13)	0.0092 (15)	−0.0151 (16)
C11	0.061 (2)	0.049 (2)	0.062 (2)	0.0101 (17)	0.0192 (18)	−0.0024 (16)
C12	0.084 (3)	0.091 (4)	0.082 (3)	0.031 (3)	−0.007 (2)	−0.005 (3)
C13	0.0460 (18)	0.0434 (17)	0.0442 (16)	−0.0052 (14)	0.0158 (14)	−0.0030 (14)
O14	0.0460 (14)	0.123 (3)	0.0396 (12)	−0.0274 (15)	0.0050 (10)	−0.0020 (15)
C15	0.050 (2)	0.169 (6)	0.068 (3)	−0.030 (3)	0.002 (2)	−0.007 (3)
C16	0.0455 (18)	0.0424 (16)	0.0326 (14)	−0.0022 (14)	0.0122 (13)	0.0018 (12)
O17	0.0614 (14)	0.0323 (11)	0.0345 (11)	−0.0037 (9)	0.0144 (10)	−0.0016 (8)
C18	0.072 (2)	0.0333 (16)	0.0446 (18)	−0.0032 (15)	0.0209 (16)	−0.0025 (14)
C19	0.074 (2)	0.0399 (17)	0.0445 (18)	−0.0042 (17)	0.0159 (17)	−0.0093 (14)
C20	0.100 (3)	0.059 (2)	0.064 (2)	0.021 (2)	0.033 (2)	−0.0100 (19)
C21	0.060 (2)	0.073 (3)	0.063 (2)	0.008 (2)	0.0279 (19)	−0.003 (2)
C22	0.058 (2)	0.0506 (19)	0.0356 (16)	−0.0047 (16)	0.0033 (14)	−0.0042 (14)
O23	0.152 (3)	0.0401 (14)	0.0610 (17)	−0.0170 (16)	0.0458 (18)	0.0006 (12)
C24	0.134 (4)	0.056 (3)	0.078 (3)	−0.028 (3)	0.013 (3)	−0.023 (2)
C25	0.051 (2)	0.079 (3)	0.083 (3)	0.002 (2)	0.003 (2)	−0.002 (2)
C26	0.114 (4)	0.081 (3)	0.036 (2)	0.000 (3)	−0.001 (2)	0.0025 (19)
C27	0.051 (2)	0.0419 (17)	0.0427 (18)	−0.0075 (15)	0.0140 (15)	0.0026 (14)
O28	0.122 (2)	0.0554 (16)	0.0639 (16)	−0.0216 (16)	0.0474 (17)	0.0042 (13)

Geometric parameters (Å, º) top

O1—C8A	1.361 (4)	C15—H15B	0.9599
O1—C2	1.372 (4)	C15—H15C	0.9599
C2—C3	1.335 (5)	C16—O17	1.452 (3)
C2—C11	1.489 (5)	C16—C27	1.499 (4)
C3—C4	1.438 (5)	C16—C21	1.525 (5)
C3—H3	0.9300	C16—C22	1.555 (5)
C4—O10	1.238 (4)	O17—C18	1.364 (4)
C4—C4A	1.477 (4)	C18—O23	1.190 (4)
C4A—C8A	1.388 (4)	C18—C19	1.502 (5)
C4A—C5	1.397 (5)	C19—C24	1.517 (5)
C5—C6	1.361 (5)	C19—C20	1.543 (6)
C5—H5	0.9300	C19—C22	1.554 (5)
C6—C7	1.403 (5)	C20—C21	1.556 (7)
C6—H6	0.9300	C20—H20A	0.9700
C7—C8	1.375 (4)	C20—H20B	0.9700
C7—O9	1.408 (4)	C21—H21A	0.9700
C8—C8A	1.412 (4)	C21—H21B	0.9700
C8—C13	1.486 (4)	C22—C25	1.522 (6)
O9—C27	1.346 (4)	C22—C26	1.542 (5)
C11—C12	1.506 (6)	C24—H24A	0.9599
C11—H11A	0.9700	C24—H24B	0.9599
C11—H11B	0.9700	C24—H24C	0.9599
C12—H12A	0.9599	C25—H25A	0.9599
C12—H12B	0.9599	C25—H25B	0.9599
C12—H12C	0.9599	C25—H25C	0.9599
C13—O14	1.401 (4)	C26—H26A	0.9599
C13—H13A	0.9700	C26—H26B	0.9599
C13—H13B	0.9700	C26—H26C	0.9599
O14—C15	1.418 (5)	C27—O28	1.189 (4)
C15—H15A	0.9599

C8A—O1—C2	118.9 (3)	O17—C16—C21	106.4 (3)
C3—C2—O1	122.2 (3)	C27—C16—C21	115.0 (3)
C3—C2—C11	127.2 (3)	O17—C16—C22	102.1 (2)
O1—C2—C11	110.6 (3)	C27—C16—C22	116.5 (3)
C2—C3—C4	122.6 (3)	C21—C16—C22	104.3 (3)
C2—C3—H3	118.7	C18—O17—C16	105.9 (2)
C4—C3—H3	118.7	O23—C18—O17	121.5 (3)
O10—C4—C3	123.9 (3)	O23—C18—C19	130.9 (3)
O10—C4—C4A	121.6 (3)	O17—C18—C19	107.6 (3)
C3—C4—C4A	114.5 (3)	C18—C19—C24	114.6 (3)
C8A—C4A—C5	118.6 (3)	C18—C19—C20	102.6 (3)
C8A—C4A—C4	118.6 (3)	C24—C19—C20	115.5 (4)
C5—C4A—C4	122.7 (3)	C18—C19—C22	99.4 (3)
C6—C5—C4A	121.4 (3)	C24—C19—C22	119.2 (3)
C6—C5—H5	119.3	C20—C19—C22	103.0 (3)
C4A—C5—H5	119.3	C19—C20—C21	103.8 (3)
C5—C6—C7	118.3 (3)	C19—C20—H20A	111.0
C5—C6—H6	120.9	C21—C20—H20A	111.0
C7—C6—H6	120.9	C19—C20—H20B	111.0
C8—C7—C6	123.6 (3)	C21—C20—H20B	111.0
C8—C7—O9	118.2 (3)	H20A—C20—H20B	109.0
C6—C7—O9	117.9 (3)	C16—C21—C20	101.1 (3)
C7—C8—C8A	116.0 (3)	C16—C21—H21A	111.6
C7—C8—C13	123.5 (3)	C20—C21—H21A	111.6
C8A—C8—C13	120.6 (3)	C16—C21—H21B	111.6
O1—C8A—C4A	123.0 (3)	C20—C21—H21B	111.6
O1—C8A—C8	114.9 (3)	H21A—C21—H21B	109.4
C4A—C8A—C8	122.2 (3)	C25—C22—C26	109.5 (3)
C27—O9—C7	116.5 (2)	C25—C22—C19	113.9 (3)
C2—C11—C12	114.4 (3)	C26—C22—C19	114.0 (3)
C2—C11—H11A	108.7	C25—C22—C16	113.1 (3)
C12—C11—H11A	108.7	C26—C22—C16	114.5 (3)
C2—C11—H11B	108.7	C19—C22—C16	91.0 (3)
C12—C11—H11B	108.7	C19—C24—H24A	109.5
H11A—C11—H11B	107.6	C19—C24—H24B	109.5
C11—C12—H12A	109.5	H24A—C24—H24B	109.5
C11—C12—H12B	109.5	C19—C24—H24C	109.5
H12A—C12—H12B	109.5	H24A—C24—H24C	109.5
C11—C12—H12C	109.5	H24B—C24—H24C	109.5
H12A—C12—H12C	109.5	C22—C25—H25A	109.5
H12B—C12—H12C	109.5	C22—C25—H25B	109.5
O14—C13—C8	109.7 (2)	H25A—C25—H25B	109.5
O14—C13—H13A	109.7	C22—C25—H25C	109.5
C8—C13—H13A	109.7	H25A—C25—H25C	109.5
O14—C13—H13B	109.7	H25B—C25—H25C	109.5
C8—C13—H13B	109.7	C22—C26—H26A	109.5
H13A—C13—H13B	108.2	C22—C26—H26B	109.5
C13—O14—C15	111.4 (3)	H26A—C26—H26B	109.5
O14—C15—H15A	109.5	C22—C26—H26C	109.5
O14—C15—H15B	109.5	H26A—C26—H26C	109.5
H15A—C15—H15B	109.5	H26B—C26—H26C	109.5
O14—C15—H15C	109.5	O28—C27—O9	124.3 (3)
H15A—C15—H15C	109.5	O28—C27—C16	122.1 (3)
H15B—C15—H15C	109.5	O9—C27—C16	113.6 (3)
O17—C16—C27	111.3 (2)

C8A—O1—C2—C3	0.1 (4)	C16—O17—C18—C19	−0.5 (4)
C8A—O1—C2—C11	−179.1 (3)	O23—C18—C19—C24	19.0 (7)
O1—C2—C3—C4	−2.1 (5)	O17—C18—C19—C24	−163.2 (4)
C11—C2—C3—C4	176.8 (3)	O23—C18—C19—C20	−107.0 (5)
C2—C3—C4—O10	−175.3 (3)	O17—C18—C19—C20	70.8 (4)
C2—C3—C4—C4A	3.9 (5)	O23—C18—C19—C22	147.3 (5)
O10—C4—C4A—C8A	175.4 (3)	O17—C18—C19—C22	−34.9 (4)
C3—C4—C4A—C8A	−3.8 (4)	C18—C19—C20—C21	−68.6 (3)
O10—C4—C4A—C5	−2.5 (5)	C24—C19—C20—C21	166.0 (4)
C3—C4—C4A—C5	178.3 (3)	C22—C19—C20—C21	34.3 (3)
C8A—C4A—C5—C6	−0.9 (5)	O17—C16—C21—C20	69.0 (3)
C4—C4A—C5—C6	177.0 (4)	C27—C16—C21—C20	−167.3 (3)
C4A—C5—C6—C7	1.2 (5)	C22—C16—C21—C20	−38.4 (4)
C5—C6—C7—C8	−1.6 (5)	C19—C20—C21—C16	2.2 (4)
C5—C6—C7—O9	−175.4 (3)	C18—C19—C22—C25	−64.7 (4)
C6—C7—C8—C8A	1.4 (4)	C24—C19—C22—C25	60.5 (5)
O9—C7—C8—C8A	175.3 (2)	C20—C19—C22—C25	−170.1 (3)
C6—C7—C8—C13	−177.5 (3)	C18—C19—C22—C26	168.6 (4)
O9—C7—C8—C13	−3.7 (4)	C24—C19—C22—C26	−66.1 (5)
C2—O1—C8A—C4A	−0.1 (4)	C20—C19—C22—C26	63.3 (4)
C2—O1—C8A—C8	179.2 (3)	C18—C19—C22—C16	51.2 (3)
C5—C4A—C8A—O1	−179.8 (3)	C24—C19—C22—C16	176.4 (4)
C4—C4A—C8A—O1	2.1 (5)	C20—C19—C22—C16	−54.2 (3)
C5—C4A—C8A—C8	0.9 (5)	O17—C16—C22—C25	63.1 (4)
C4—C4A—C8A—C8	−177.2 (3)	C27—C16—C22—C25	−58.3 (4)
C7—C8—C8A—O1	179.6 (2)	C21—C16—C22—C25	173.7 (3)
C13—C8—C8A—O1	−1.4 (4)	O17—C16—C22—C26	−170.5 (3)
C7—C8—C8A—C4A	−1.1 (4)	C27—C16—C22—C26	68.1 (4)
C13—C8—C8A—C4A	177.9 (3)	C21—C16—C22—C26	−59.9 (4)
C8—C7—O9—C27	110.5 (3)	O17—C16—C22—C19	−53.4 (3)
C6—C7—O9—C27	−75.4 (4)	C27—C16—C22—C19	−174.9 (3)
C3—C2—C11—C12	130.5 (4)	C21—C16—C22—C19	57.2 (3)
O1—C2—C11—C12	−50.4 (4)	C7—O9—C27—O28	−5.3 (5)
C7—C8—C13—O14	−96.3 (4)	C7—O9—C27—C16	176.5 (3)
C8A—C8—C13—O14	84.8 (4)	O17—C16—C27—O28	168.4 (3)
C8—C13—O14—C15	−167.8 (4)	C21—C16—C27—O28	47.3 (5)
C27—C16—O17—C18	160.9 (3)	C22—C16—C27—O28	−75.2 (4)
C21—C16—O17—C18	−73.1 (3)	O17—C16—C27—O9	−13.5 (4)
C22—C16—O17—C18	35.9 (3)	C21—C16—C27—O9	−134.5 (3)
C16—O17—C18—O23	177.6 (4)	C22—C16—C27—O9	102.9 (3)

Experimental details

Crystal data
Chemical formula	C₂₃H₂₆O₇
M_r	414.44
Crystal system, space group	Monoclinic, P2₁
Temperature (K)	293
a, b, c (Å)	7.632 (3), 14.159 (6), 10.579 (4)
β (°)	109.240 (5)
V (Å³)	1079.3 (8)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.22 × 0.12 × 0.05

Data collection
Diffractometer	Bruker SMART APEX CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 2000)
T_min, T_max	0.980, 0.995
No. of measured, independent and observed [I > 2σ(I)] reflections	4560, 2016, 1713
R_int	0.056
(sin θ/λ)_max (Å⁻¹)	0.599

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.046, 0.120, 0.96
No. of reflections	2016
No. of parameters	277
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.22, −0.22

Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Acknowledgements

The authors acknowledge Miss Wang Jingmei, Center of Analysis and Measurement, Fudan University, for her help with the crystal structure analysis.

References

Bruker (2000). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Yu, D., Chen, C.-H., Brossi, A. & Lee, K.-H. (2004). J. Med. Chem. 47, 4072–4082 Web of Science CrossRef PubMed CAS Google Scholar

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