organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

(Z)-1,3,4a-Tri­methyl-5,5-di­phenyl-6-oxa-1,3-di­aza­bi­cyclo­[4.2.0]octane-2,4-dione

aSchool of Pharmacy, Anhui Medical University, Hefei 230032, People's Republic of China
*Correspondence e-mail: tangwjster@gmail.com

(Received 23 January 2008; accepted 8 March 2008; online 4 April 2008)

The title compound, C20H20N2O3, is a head-to-tail oxetane, one of the regioisomers obtained by the the Paternó–Büchi reaction of 1,3-dimethyl­thymine with benzophenone. The oxetane ring is folded, the dihedral angle between the C—O—C and C—C—C planes being 14.4 (2)°. The dihedral angle between the two phenyl rings is 64.3 (2)°. The pyrimidine ring adopts a boat conformation. The crystal structure involves weak C—H⋯O hydrogen bonds.

Related literature

For related literature, see: Hei et al. (2005[Hei, X. M., Song, Q. H., Tang, W. J., Wang, H. B. & Guo, Q. X. (2005). J. Org. Chem. 70, 2522-2527.]); Prakash et al. (1997[Prakash, G., Fettinger, J. C. & Falvey, D. E. (1997). Acta Cryst. C53, 979-981.]).

[Scheme 1]

Experimental

Crystal data
  • C20H20N2O3

  • Mr = 336.38

  • Monoclinic, P 21 /n

  • a = 8.1341 (7) Å

  • b = 9.1004 (13) Å

  • c = 23.485 (2) Å

  • β = 97.334 (2)°

  • V = 1724.2 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.09 mm−1

  • T = 298 (2) K

  • 0.45 × 0.41 × 0.18 mm

Data collection
  • Bruker SMART diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.962, Tmax = 0.984

  • 8774 measured reflections

  • 3039 independent reflections

  • 1818 reflections with I > 2σ(I)

  • Rint = 0.036

Refinement
  • R[F2 > 2σ(F2)] = 0.044

  • wR(F2) = 0.117

  • S = 1.01

  • 3039 reflections

  • 226 parameters

  • H-atom parameters constrained

  • Δρmax = 0.20 e Å−3

  • Δρmin = −0.18 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C3—H3⋯O2i 0.98 2.53 3.431 (3) 153
C7—H7⋯O1 0.93 2.37 2.745 (3) 104
C8—H8⋯O1ii 0.93 2.59 3.513 (3) 171
C13—H13⋯O1 0.93 2.41 2.752 (3) 101
C17—H17⋯O3 0.93 2.55 3.040 (3) 113
C20—H20B⋯O2 0.96 2.29 2.682 (4) 104
Symmetry codes: (i) [-x+{\script{5\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) [-x+{\script{3\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}].

Data collection: SMART (Siemens, 1996[Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Siemens, 1996[Siemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

A [2 + 2] photocycloaddition (Paternò-Büchi reaction) of the 5–6 double bond of 1,3-dimethylthymine (DMT) with the carbonyl of benzophenone generates two regioisomers, head-to-head and head-to-tail oxetanes (Fig. 1). We have observed the temperature dependence of the regioselectivity (Hei et al., 2005). The crystal structure of the head-to-head oxetane has already been published (Prakash et al., 1997). In the present study, an X-ray crystallographic analysis of the head-to-tail oxetane has been undertaken to establish its structure and configuration.

The structure is similar to that observed in the head-to-head oxetane (Prakash et al., 1997). The bond lengths and angles in the title compound are in good agreement with expected values. The oxetane ring is folded and the dihedral angle between the C1—O1—C3 and C1—C2—C3 planes is 14.4 (2)° (Fig. 2). The dihedral angle between the two phenyl rings is 64.3 (2)° and the pyrimidine ring adopts a boat conformation. The crystal structure involves weak C—H···O hydrogen bonds.

Related literature top

For related literature, see: Hei et al. (2005); Prakash et al. (1997).

Experimental top

The title compound was prepared by first dissolving DMT (0.77 g, 5.0 mmol) and benzophenone (1.82 g, 10.0 mmol) in CH3CN (100 ml). The resulting solution was placed in a photochemical apparatus (Pyrex), purged with nitrogen, degassed for 30 min, and irradiated with a 300 W mercury high-pressure lamp for 10 h. The solvent was then rotary evaporated and the oxetane was purified by silica gel chromatography using a 4:1 petroleum ether/ethyl acetate solvent mixture. The fractions containing the h-t oxetane were combined, and the solvent removed by rotary evaporation. The purified oxetane was subsequently crystallized by dissolving the residue in 10 ml of ethyl acetate and adding n-hexane to the solution until it turned cloudy. Upon standing at room temperature, a colorless block appeared and was separated from the solvent by decanting.

Refinement top

All H atoms were positioned geometrically and refined using a riding model, with C—H = 0.98 Å (methine), 0.96 Å (methyl) and 0.93 Å (aromatic); Uiso(H) = 1.2 Ueq(C, O) or 1.5 Ueq(C) for the methyl group.

Computing details top

Data collection: SMART (Siemens, 1996); cell refinement: SAINT (Siemens, 1996); data reduction: SAINT (Siemens, 1996); 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
[Figure 1] Fig. 1. Formation of the two regioisomers of the Paternó-Büchi reaction.
[Figure 2] Fig. 2. Molecular structure of the title compound, with the atomic numbering scheme, and displacement ellipsoids drawn at the 30% probability level.
(Z)-1,3,4a-Trimethyl-5,5-diphenyl-6-oxa-1,3-diazabicyclo[4.2.0]octane- 2,4-dione top
Crystal data top
C20H20N2O3F(000) = 712
Mr = 336.38Dx = 1.296 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 8.1341 (7) ÅCell parameters from 1952 reflections
b = 9.1004 (13) Åθ = 2.4–22.1°
c = 23.485 (2) ŵ = 0.09 mm1
β = 97.334 (2)°T = 298 K
V = 1724.2 (3) Å3Block, colorless
Z = 40.45 × 0.41 × 0.18 mm
Data collection top
Bruker SMART
diffractometer
3039 independent reflections
Radiation source: fine-focus sealed tube1818 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.036
ϕ and ω scansθmax = 25.0°, θmin = 1.8°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 99
Tmin = 0.962, Tmax = 0.984k = 1010
8774 measured reflectionsl = 2427
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.044Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.117H-atom parameters constrained
S = 1.01 w = 1/[σ2(Fo2) + (0.038P)2 + 0.7238P]
where P = (Fo2 + 2Fc2)/3
3039 reflections(Δ/σ)max < 0.001
226 parametersΔρmax = 0.20 e Å3
0 restraintsΔρmin = 0.18 e Å3
Crystal data top
C20H20N2O3V = 1724.2 (3) Å3
Mr = 336.38Z = 4
Monoclinic, P21/nMo Kα radiation
a = 8.1341 (7) ŵ = 0.09 mm1
b = 9.1004 (13) ÅT = 298 K
c = 23.485 (2) Å0.45 × 0.41 × 0.18 mm
β = 97.334 (2)°
Data collection top
Bruker SMART
diffractometer
3039 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1818 reflections with I > 2σ(I)
Tmin = 0.962, Tmax = 0.984Rint = 0.036
8774 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0440 restraints
wR(F2) = 0.117H-atom parameters constrained
S = 1.01Δρmax = 0.20 e Å3
3039 reflectionsΔρmin = 0.18 e Å3
226 parameters
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
N11.2692 (2)0.5663 (2)0.21196 (8)0.0491 (5)
N21.2831 (2)0.6885 (2)0.12510 (8)0.0492 (5)
O10.97763 (19)0.60800 (17)0.19685 (6)0.0469 (4)
O21.4490 (2)0.7527 (2)0.20642 (8)0.0750 (6)
O31.1732 (2)0.5833 (2)0.04218 (7)0.0625 (5)
C10.9036 (3)0.5849 (2)0.13794 (8)0.0379 (5)
C21.0673 (3)0.4991 (2)0.12589 (9)0.0380 (5)
C31.1126 (3)0.5076 (3)0.19078 (9)0.0427 (6)
H31.09490.41270.20880.051*
C41.3391 (3)0.6743 (3)0.18356 (11)0.0503 (6)
C51.1782 (3)0.5906 (3)0.09400 (10)0.0440 (6)
C60.7544 (3)0.4834 (2)0.13563 (9)0.0398 (6)
C70.7166 (3)0.4145 (3)0.18451 (11)0.0555 (7)
H70.77810.43580.21970.067*
C80.5890 (4)0.3147 (3)0.18183 (13)0.0654 (8)
H80.56460.26950.21530.079*
C90.4977 (3)0.2812 (3)0.13056 (13)0.0617 (8)
H90.41280.21240.12890.074*
C100.5325 (3)0.3502 (3)0.08148 (12)0.0580 (7)
H100.47010.32890.04650.070*
C110.6592 (3)0.4506 (3)0.08398 (10)0.0481 (6)
H110.68150.49710.05060.058*
C120.8626 (3)0.7299 (2)0.10882 (9)0.0385 (6)
C130.8285 (3)0.8494 (3)0.14167 (11)0.0505 (6)
H130.83360.83920.18130.061*
C140.7872 (4)0.9835 (3)0.11655 (14)0.0673 (8)
H140.76451.06290.13920.081*
C150.7794 (4)0.9999 (3)0.05856 (14)0.0727 (9)
H150.75231.09060.04170.087*
C160.8116 (4)0.8830 (3)0.02531 (12)0.0666 (8)
H160.80610.89420.01420.080*
C170.8520 (3)0.7485 (3)0.05001 (10)0.0504 (6)
H170.87240.66930.02690.060*
C181.0451 (3)0.3473 (3)0.09951 (10)0.0503 (6)
H18A0.98860.35520.06120.075*
H18B0.98090.28770.12220.075*
H18C1.15170.30290.09850.075*
C191.3263 (4)0.5493 (3)0.27297 (11)0.0783 (9)
H19A1.44320.56830.27990.117*
H19B1.30460.45080.28470.117*
H19C1.26860.61750.29450.117*
C201.3705 (4)0.7944 (3)0.09317 (13)0.0803 (10)
H20A1.45390.74450.07510.121*
H20B1.42180.86760.11900.121*
H20C1.29310.84080.06440.121*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0490 (13)0.0549 (13)0.0392 (12)0.0034 (11)0.0110 (9)0.0031 (10)
N20.0448 (12)0.0524 (13)0.0499 (13)0.0048 (10)0.0035 (10)0.0005 (10)
O10.0509 (10)0.0554 (11)0.0329 (9)0.0088 (8)0.0009 (7)0.0072 (7)
O20.0666 (13)0.0819 (14)0.0730 (13)0.0225 (12)0.0044 (11)0.0256 (11)
O30.0560 (12)0.0921 (14)0.0402 (11)0.0015 (10)0.0092 (8)0.0015 (9)
C10.0403 (14)0.0433 (14)0.0290 (12)0.0050 (11)0.0004 (10)0.0041 (10)
C20.0387 (13)0.0403 (13)0.0336 (12)0.0042 (11)0.0008 (10)0.0043 (10)
C30.0467 (15)0.0395 (14)0.0402 (14)0.0043 (12)0.0011 (11)0.0030 (11)
C40.0450 (15)0.0526 (17)0.0519 (16)0.0041 (13)0.0012 (13)0.0122 (13)
C50.0377 (14)0.0522 (16)0.0414 (15)0.0069 (12)0.0024 (11)0.0021 (12)
C60.0379 (13)0.0414 (14)0.0405 (14)0.0063 (11)0.0067 (11)0.0006 (11)
C70.0573 (17)0.0665 (18)0.0442 (15)0.0029 (15)0.0119 (12)0.0020 (13)
C80.0656 (19)0.070 (2)0.065 (2)0.0033 (16)0.0253 (16)0.0127 (15)
C90.0438 (16)0.0573 (18)0.085 (2)0.0021 (14)0.0134 (15)0.0074 (16)
C100.0402 (15)0.0623 (18)0.0680 (19)0.0026 (14)0.0062 (13)0.0037 (15)
C110.0447 (15)0.0519 (16)0.0467 (15)0.0002 (13)0.0015 (12)0.0076 (12)
C120.0324 (13)0.0391 (14)0.0434 (14)0.0010 (10)0.0027 (10)0.0035 (11)
C130.0477 (15)0.0505 (16)0.0512 (15)0.0059 (13)0.0016 (12)0.0098 (13)
C140.073 (2)0.0418 (16)0.083 (2)0.0119 (14)0.0031 (16)0.0150 (15)
C150.087 (2)0.0434 (17)0.083 (2)0.0064 (15)0.0078 (18)0.0103 (16)
C160.089 (2)0.0519 (18)0.0564 (17)0.0058 (16)0.0001 (15)0.0085 (14)
C170.0587 (17)0.0438 (15)0.0483 (16)0.0068 (13)0.0059 (12)0.0010 (12)
C180.0462 (15)0.0501 (15)0.0524 (15)0.0065 (12)0.0026 (12)0.0129 (12)
C190.082 (2)0.095 (2)0.0493 (17)0.0024 (19)0.0221 (15)0.0001 (16)
C200.078 (2)0.082 (2)0.082 (2)0.0240 (18)0.0150 (18)0.0105 (17)
Geometric parameters (Å, º) top
N1—C41.353 (3)C9—H90.9300
N1—C31.412 (3)C10—C111.373 (3)
N1—C191.457 (3)C10—H100.9300
N2—C51.377 (3)C11—H110.9300
N2—C41.396 (3)C12—C131.381 (3)
N2—C201.460 (3)C12—C171.383 (3)
O1—C31.450 (3)C13—C141.379 (4)
O1—C11.452 (2)C13—H130.9300
O2—C41.214 (3)C14—C151.364 (4)
O3—C51.214 (3)C14—H140.9300
C1—C121.504 (3)C15—C161.365 (4)
C1—C61.521 (3)C15—H150.9300
C1—C21.600 (3)C16—C171.376 (3)
C2—C51.497 (3)C16—H160.9300
C2—C181.515 (3)C17—H170.9300
C2—C31.523 (3)C18—H18A0.9600
C3—H30.9800C18—H18B0.9600
C6—C71.376 (3)C18—H18C0.9600
C6—C111.386 (3)C19—H19A0.9600
C7—C81.375 (4)C19—H19B0.9600
C7—H70.9300C19—H19C0.9600
C8—C91.366 (4)C20—H20A0.9600
C8—H80.9300C20—H20B0.9600
C9—C101.373 (4)C20—H20C0.9600
C4—N1—C3121.2 (2)C11—C10—C9120.2 (3)
C4—N1—C19117.4 (2)C11—C10—H10119.9
C3—N1—C19117.8 (2)C9—C10—H10119.9
C5—N2—C4124.3 (2)C10—C11—C6120.9 (2)
C5—N2—C20117.6 (2)C10—C11—H11119.6
C4—N2—C20116.6 (2)C6—C11—H11119.6
C3—O1—C192.41 (14)C13—C12—C17118.0 (2)
O1—C1—C12110.28 (17)C13—C12—C1119.0 (2)
O1—C1—C6110.74 (17)C17—C12—C1122.9 (2)
C12—C1—C6112.78 (18)C14—C13—C12120.9 (2)
O1—C1—C289.20 (14)C14—C13—H13119.6
C12—C1—C2119.28 (18)C12—C13—H13119.6
C6—C1—C2112.08 (17)C15—C14—C13120.1 (3)
C5—C2—C18110.54 (19)C15—C14—H14119.9
C5—C2—C3112.83 (19)C13—C14—H14119.9
C18—C2—C3117.16 (19)C14—C15—C16119.9 (3)
C5—C2—C1112.63 (18)C14—C15—H15120.1
C18—C2—C1117.30 (18)C16—C15—H15120.1
C3—C2—C184.20 (15)C15—C16—C17120.3 (3)
N1—C3—O1112.77 (18)C15—C16—H16119.8
N1—C3—C2117.63 (19)C17—C16—H16119.8
O1—C3—C292.34 (15)C16—C17—C12120.7 (2)
N1—C3—H3110.9C16—C17—H17119.6
O1—C3—H3110.9C12—C17—H17119.6
C2—C3—H3110.9C2—C18—H18A109.5
O2—C4—N1122.7 (2)C2—C18—H18B109.5
O2—C4—N2120.6 (3)H18A—C18—H18B109.5
N1—C4—N2116.6 (2)C2—C18—H18C109.5
O3—C5—N2120.4 (2)H18A—C18—H18C109.5
O3—C5—C2121.7 (2)H18B—C18—H18C109.5
N2—C5—C2117.8 (2)N1—C19—H19A109.5
C7—C6—C11118.2 (2)N1—C19—H19B109.5
C7—C6—C1120.6 (2)H19A—C19—H19B109.5
C11—C6—C1121.07 (19)N1—C19—H19C109.5
C8—C7—C6120.7 (2)H19A—C19—H19C109.5
C8—C7—H7119.7H19B—C19—H19C109.5
C6—C7—H7119.7N2—C20—H20A109.5
C9—C8—C7120.7 (3)N2—C20—H20B109.5
C9—C8—H8119.7H20A—C20—H20B109.5
C7—C8—H8119.7N2—C20—H20C109.5
C8—C9—C10119.4 (3)H20A—C20—H20C109.5
C8—C9—H9120.3H20B—C20—H20C109.5
C10—C9—H9120.3
C3—O1—C1—C12131.48 (18)C20—N2—C5—C2170.0 (2)
C3—O1—C1—C6102.98 (19)C18—C2—C5—O337.6 (3)
C3—O1—C1—C210.39 (16)C3—C2—C5—O3170.9 (2)
O1—C1—C2—C5102.41 (19)C1—C2—C5—O395.8 (3)
C12—C1—C2—C510.5 (3)C18—C2—C5—N2144.8 (2)
C6—C1—C2—C5145.47 (19)C3—C2—C5—N211.4 (3)
O1—C1—C2—C18127.57 (19)C1—C2—C5—N281.9 (2)
C12—C1—C2—C18119.5 (2)O1—C1—C6—C76.9 (3)
C6—C1—C2—C1815.5 (3)C12—C1—C6—C7131.1 (2)
O1—C1—C2—C39.93 (15)C2—C1—C6—C791.0 (2)
C12—C1—C2—C3122.9 (2)O1—C1—C6—C11177.12 (19)
C6—C1—C2—C3102.19 (18)C12—C1—C6—C1153.0 (3)
C4—N1—C3—O172.4 (3)C2—C1—C6—C1185.0 (2)
C19—N1—C3—O185.8 (3)C11—C6—C7—C80.7 (4)
C4—N1—C3—C233.3 (3)C1—C6—C7—C8175.3 (2)
C19—N1—C3—C2168.6 (2)C6—C7—C8—C90.3 (4)
C1—O1—C3—N1132.30 (19)C7—C8—C9—C101.1 (4)
C1—O1—C3—C210.93 (17)C8—C9—C10—C110.7 (4)
C5—C2—C3—N115.1 (3)C9—C10—C11—C60.4 (4)
C18—C2—C3—N1115.0 (2)C7—C6—C11—C101.1 (3)
C1—C2—C3—N1127.2 (2)C1—C6—C11—C10174.9 (2)
C5—C2—C3—O1102.19 (19)O1—C1—C12—C1327.7 (3)
C18—C2—C3—O1127.7 (2)C6—C1—C12—C1396.7 (2)
C1—C2—C3—O19.95 (15)C2—C1—C12—C13128.7 (2)
C3—N1—C4—O2160.5 (2)O1—C1—C12—C17154.5 (2)
C19—N1—C4—O22.3 (4)C6—C1—C12—C1781.1 (3)
C3—N1—C4—N222.0 (3)C2—C1—C12—C1753.5 (3)
C19—N1—C4—N2179.8 (2)C17—C12—C13—C140.8 (4)
C5—N2—C4—O2169.6 (2)C1—C12—C13—C14178.7 (2)
C20—N2—C4—O23.8 (3)C12—C13—C14—C150.0 (4)
C5—N2—C4—N17.9 (3)C13—C14—C15—C160.5 (5)
C20—N2—C4—N1173.7 (2)C14—C15—C16—C170.1 (5)
C4—N2—C5—O3157.9 (2)C15—C16—C17—C120.7 (4)
C20—N2—C5—O37.7 (3)C13—C12—C17—C161.2 (4)
C4—N2—C5—C224.4 (3)C1—C12—C17—C16179.0 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···O2i0.982.533.431 (3)153
C7—H7···O10.932.372.745 (3)104
C8—H8···O1ii0.932.593.513 (3)171
C13—H13···O10.932.412.752 (3)101
C17—H17···O30.932.553.040 (3)113
C20—H20B···O20.962.292.682 (4)104
Symmetry codes: (i) x+5/2, y1/2, z+1/2; (ii) x+3/2, y1/2, z+1/2.

Experimental details

Crystal data
Chemical formulaC20H20N2O3
Mr336.38
Crystal system, space groupMonoclinic, P21/n
Temperature (K)298
a, b, c (Å)8.1341 (7), 9.1004 (13), 23.485 (2)
β (°) 97.334 (2)
V3)1724.2 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.09
Crystal size (mm)0.45 × 0.41 × 0.18
Data collection
DiffractometerBruker SMART
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.962, 0.984
No. of measured, independent and
observed [I > 2σ(I)] reflections
8774, 3039, 1818
Rint0.036
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.044, 0.117, 1.01
No. of reflections3039
No. of parameters226
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.20, 0.18

Computer programs: SMART (Siemens, 1996), SAINT (Siemens, 1996), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C3—H3···O2i0.982.533.431 (3)153
C7—H7···O10.932.372.745 (3)104
C8—H8···O1ii0.932.593.513 (3)171
C13—H13···O10.932.412.752 (3)101
C17—H17···O30.932.553.040 (3)113
C20—H20B···O20.962.292.682 (4)104
Symmetry codes: (i) x+5/2, y1/2, z+1/2; (ii) x+3/2, y1/2, z+1/2.
 

Acknowledgements

This work was supported by the Grants for Scientific Research of BSKY (grant No. XJ200712) from Anhui Medical University.

References

First citationHei, X. M., Song, Q. H., Tang, W. J., Wang, H. B. & Guo, Q. X. (2005). J. Org. Chem. 70, 2522–2527.  Web of Science CrossRef PubMed CAS Google Scholar
First citationPrakash, G., Fettinger, J. C. & Falvey, D. E. (1997). Acta Cryst. C53, 979–981.  CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSiemens (1996). SMART and SAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.  Google Scholar

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