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

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COMMUNICATIONS
ISSN: 2056-9890

(–)-(4R,5S)-4-Methyl-3-[2(R)-(4-methyl­phen­yl)propion­yl]-5-phenyl­oxazolidin-2-one

aDepartment of Chemistry, Queen Mary, University of London, Mile End Road, London E1 4NS, England, bDepartment of Chemistry, University of Hull, Cottingham Road, Kingston-upon-Hull HU6 7RX, England, cOnyx Scientific Limited, Units 97-98, Silverbriar, Sunderland Enterprise Park East, Sunderland SR5 2TQ, England, and dDepartment of Chemistry, J. J. Strossmayer University of Osijek, Trg Sv. Trojstva 3, Osijek 31000, Croatia
*Correspondence e-mail: j.eames@hull.ac.uk

(Received 27 June 2006; accepted 12 August 2006; online 23 August 2006)

In the title compound, C20H21NO3, formed from enanti­omerically pure (+)-(4R,5S)-4-methyl-5-phenyl-2-oxazolidin­one and racemic 2-(4-methyl­phen­yl)propanoyl chloride, the two carbonyl groups are oriented anti to each other, and the methyl group of the (4-methyl­phen­yl)propionyl substituent lies close to the mean plane of the five-membered ring.

Comment

The title compound is the third in a series of structurally related compounds, introduced in our earlier report (Coumbarides, Eames et al., 2006[Coumbarides, G. S., Eames, J., Motevalli, M., Malatesti, N. & Yohannes, Y. (2006). Acta Cryst. E62, o4032-o4034.]). With R1 = 4-(CH3)C6H4, the reaction shown in that report yielded the antisyn and synsyn diastereomers in 38 and 38% yields, respectively. The title compound, (I)[link], is the antisyn diastereomer (Fig. 1[link]). In the crystal structure, the conformation of the central portion of the mol­ecule is closely comparable with that in the previously reported derivatives (Coumbarides, Eames et al., 2006[Coumbarides, G. S., Eames, J., Motevalli, M., Malatesti, N. & Yohannes, Y. (2006). Acta Cryst. E62, o4032-o4034.]; Coumbarides, Dingjan et al., 2006[Coumbarides, G. S., Dingjan, M., Eames, J., Motevalli, M. & Nela, M. (2006). Acta Cryst. E62, o4035-o4036.]); in the twisted five-membered ring, atoms C1 and C2 lie, respectively, 0.245 (4) Å above and −0.202 (4) Å below the plane defined by atoms O1, O2, N1 and C3. The carbonyl groups (C3=O2 and C11=O3) are oriented anti to each other, with the torsion angle O3—C11—N1—C3 = −169.3 (2)°. The orientation of the 4-(CH3)C6H4 substituent resembles most closely that in the 4-(iBu)C6H4 derivative (Coumbarides, Dingjan et al., 2006[Coumbarides, G. S., Dingjan, M., Eames, J., Motevalli, M. & Nela, M. (2006). Acta Cryst. E62, o4035-o4036.]), with the C19 methyl group lying close to the mean plane of the five-membered ring [deviating by 0.138 (8) Å from it] and the torsion angle N1—C11—C12—C13 = 78.7 (3)°.

[Scheme 1]
[Figure 1]
Figure 1
The mol­ecular structure of the title compound, showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level and H atoms have been omitted.

Experimental

The experimental procedure is comparable with that reported previously (Coumbarides, Eames et al., 2006[Coumbarides, G. S., Eames, J., Motevalli, M., Malatesti, N. & Yohannes, Y. (2006). Acta Cryst. E62, o4032-o4034.]). The actual quanti­ties used for the preparation of (I) were: n-butyl­lithium (15.45 ml, 2.5 M in hexa­nes, 38.6 mmol) and (R,S)-oxazolidinone (4.89 g, 27.6 mmol) in 60 ml tetrahydrofuran (THF), combined with a solution of (rac)-2-(4-methyl­phen­yl)propanoyl chloride (5.02 g, 27.6 mmol) in 10 ml THF. The crude residue was purified by flash column chromatography on silica gel, eluting with light petroleum (b.p. 313–333 K)/diethyl ether (1:1), to give a separable diastereoisomeric mixture in the ratio antisyn:syn,syn 50:50. The antisyn diastereomer was obtained as colourless crystals (3.39 g, 38% yield, m.p. 341–343 K, RF 0.71 [light petroleum (b.p 313–333 K)/diethyl ether, 7:3]. Spectroscopic analysis: [α]20D = −164.5 (CHCl3, 293 K, concentration 0.18 g per 100 ml); IR (CHCl3, νmax/cm−1): 1779 (C=O), 1710 (C=O); 1H NMR (270 MHz; CDCl3): δ 7.36–7.24 (9H, m, 9 × CH; Ar and Ph), 5.46 (1H, d, J = 6.9 Hz, CHO), 5.07 (1H, q, J = 7.1 Hz, ArCH), 4.65 (1H, m, NCHCH3), 2.31 (3H, s, CH3; Ar), 1.46 (3H, d, J = 7.1 Hz, CH3CH), 0.91 (3H, d, J = 6.9 Hz, CH3CHN); 13C NMR (67.5 MHz; CDCl3): δ 174.8 (NC=O), 152.9 (OC=O), 137.7, 137.1, 133.9 (3 × i-C; Ar and Ph), 129.7, 129.1, 128.3, 128.3, 126.1 (5 × CH; Ar and Ph), 79.1 (PhCHO), 55.0 (CHN), 43.6 (ArCH), 21.4 (CH3; Ar), 19.8 (CH3CH), 14.5 (CH3CHN); found: MH+ 324.1187; C20H22NO3 requires 324.1194.

Crystal data
  • C20H21NO3

  • Mr = 323.38

  • Monoclinic, P 21

  • a = 13.066 (8) Å

  • b = 9.509 (8) Å

  • c = 7.201 (4) Å

  • β = 102.95 (4)°

  • V = 871.9 (10) Å3

  • Z = 2

  • Dx = 1.232 Mg m−3

  • Mo Kα radiation

  • μ = 0.08 mm−1

  • T = 160 (2) K

  • Prism, colourless

  • 0.40 × 0.30 × 0.30 mm

Data collection
  • Enraf–Nonius CAD-4 diffractometer

  • ω/2θ scans

  • Absorption correction: none

  • 1743 measured reflections

  • 1630 independent reflections

  • 1417 reflections with I > 2σ(I)

  • Rint = 0.010

  • θmax = 25.0°

  • 2 standard reflections every 100 reflections intensity decay: 1%

Refinement
  • Refinement on F2

  • R[F2 > 2σ(F2)] = 0.032

  • wR(F2) = 0.078

  • S = 1.06

  • 1630 reflections

  • 220 parameters

  • H-atom parameters constrained

  • w = 1/[σ2(Fo2) + (0.04P)2 + 0.0761P] where P = (Fo2 + 2Fc2)/3

  • (Δ/σ)max < 0.001

  • Δρmax = 0.12 e Å−3

  • Δρmin = −0.16 e Å−3

H atoms were placed in geometrically idealised positions and constrained to ride on their parent atoms, with C—H = 0.95–1.00 Å and Uiso(H) = 1.2Ueq(C) or 1.5Ueq(methyl C). The methyl groups were allowed to rotate about their local threefold axes. In the absence of significant anomalous scattering effects, the few measured Friedel pairs have been merged. The absolute configuration is assigned on the basis of the known configuration of the starting material (Coumbarides, Eames et al., 2006[Coumbarides, G. S., Eames, J., Motevalli, M., Malatesti, N. & Yohannes, Y. (2006). Acta Cryst. E62, o4032-o4034.]).

Data collection: CAD-4-PC (Enraf–Nonius, 1994[Enraf-Nonius (1994). CAD-4-PC Software. Enraf-Nonius, Delft, The Netherlands.]); cell refinement: CAD-4-PC; data reduction: XCAD4 (Harms & Wocadlo, 1995[Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997[Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]).

Supporting information


Computing details top

Data collection: CAD-4-PC (Enraf–Nonius, 1994); cell refinement: CAD-4-PC; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

(-)-(4R,5S)-4-Methyl-3-[2(R)-(4-methylphenyl)propionyl]- 5-phenyloxazolidin-2-one top
Crystal data top
C20H21NO3F(000) = 344
Mr = 323.38Dx = 1.232 Mg m3
Monoclinic, P21Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ybCell parameters from 25 reflections
a = 13.066 (8) Åθ = 9.4–12.7°
b = 9.509 (8) ŵ = 0.08 mm1
c = 7.201 (4) ÅT = 160 K
β = 102.95 (4)°Prism, colourless
V = 871.9 (10) Å30.40 × 0.30 × 0.30 mm
Z = 2
Data collection top
Enraf–Nonius CAD-4
diffractometer
Rint = 0.010
Radiation source: fine-focus sealed tubeθmax = 25.0°, θmin = 1.6°
Graphite monochromatorh = 015
ω/2θ scansk = 211
1743 measured reflectionsl = 88
1630 independent reflections2 standard reflections every 100 reflections
1417 reflections with I > 2σ(I) intensity decay: 1%
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.032H-atom parameters constrained
wR(F2) = 0.078 w = 1/[σ2(Fo2) + (0.04P)2 + 0.0761P]
where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max < 0.001
1630 reflectionsΔρmax = 0.12 e Å3
220 parametersΔρmin = 0.16 e Å3
1 restraintAbsolute structure: assigned on the basis of known starting material
Primary atom site location: structure-invariant direct methods
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.

Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane)

1.7659 (0.0199) x + 8.7456 (0.0092) y + 2.3685 (0.0098) z = 8.8989 (0.0127)

* -0.0015 (0.0008) N1 * 0.0050 (0.0024) C3 * -0.0014 (0.0007) O1 * -0.0020 (0.0010) O2 - 0.2450 (0.0044) C1 0.2015 (0.0043) C2 - 0.1382 (0.0075) C19

Rms deviation of fitted atoms = 0.0029

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 > 2σ(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
xyzUiso*/Ueq
C10.51015 (17)0.6695 (3)0.8013 (3)0.0308 (5)
H10.48410.71590.90650.037*
C20.49740 (18)0.7696 (3)0.6297 (3)0.0339 (6)
H20.49780.86860.67660.041*
C30.66853 (19)0.6938 (3)0.6989 (3)0.0393 (6)
C40.4596 (2)0.5268 (3)0.7589 (4)0.0407 (7)
H4A0.47780.46760.87290.061*
H4B0.48500.48250.65480.061*
H4C0.38320.53770.72130.061*
C50.40230 (19)0.7494 (3)0.4694 (3)0.0325 (6)
C60.31243 (19)0.8228 (3)0.4763 (4)0.0409 (7)
H60.31280.88670.57790.049*
C70.2213 (2)0.8044 (4)0.3365 (4)0.0492 (8)
H70.15940.85470.34330.059*
C80.2208 (2)0.7140 (4)0.1891 (4)0.0524 (8)
H80.15810.69990.09460.063*
C90.3109 (3)0.6431 (4)0.1769 (4)0.0547 (8)
H90.31060.58170.07270.066*
C100.4023 (2)0.6610 (3)0.3167 (4)0.0430 (7)
H100.46460.61280.30760.052*
C110.67809 (18)0.6052 (3)1.0290 (3)0.0316 (6)
C120.79737 (18)0.6083 (3)1.0771 (3)0.0342 (6)
H120.82250.58420.95960.041*
C130.83601 (17)0.7545 (3)1.1413 (3)0.0320 (6)
C140.80485 (19)0.8201 (3)1.2912 (3)0.0378 (6)
H140.75350.77661.34670.045*
C150.8470 (2)0.9478 (3)1.3615 (4)0.0400 (7)
H150.82410.99041.46440.048*
C160.92221 (18)1.0146 (3)1.2845 (4)0.0371 (6)
C170.9518 (2)0.9500 (3)1.1328 (4)0.0415 (7)
H171.00240.99431.07620.050*
C180.90949 (19)0.8226 (3)1.0614 (4)0.0381 (6)
H180.93110.78120.95630.046*
C190.8401 (2)0.4990 (3)1.2299 (4)0.0430 (7)
H19A0.81740.52251.34700.064*
H19B0.91700.49851.25550.064*
H19C0.81330.40591.18530.064*
C200.9695 (2)1.1532 (3)1.3630 (4)0.0509 (8)
H20A0.93701.22981.27920.076*
H20B1.04531.15201.37010.076*
H20C0.95691.16761.49080.076*
N10.62582 (14)0.6602 (2)0.8523 (3)0.0317 (5)
O10.59164 (13)0.7465 (2)0.5591 (2)0.0458 (5)
O20.75664 (14)0.6802 (3)0.6804 (3)0.0566 (6)
O30.62656 (13)0.5637 (2)1.1380 (2)0.0410 (5)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0269 (12)0.0347 (14)0.0304 (12)0.0006 (11)0.0059 (10)0.0005 (11)
C20.0341 (12)0.0297 (15)0.0364 (13)0.0000 (11)0.0047 (10)0.0028 (11)
C30.0340 (13)0.0503 (18)0.0333 (13)0.0036 (13)0.0072 (11)0.0092 (13)
C40.0420 (14)0.0369 (17)0.0410 (15)0.0050 (13)0.0045 (12)0.0059 (12)
C50.0359 (13)0.0299 (14)0.0293 (12)0.0035 (12)0.0024 (10)0.0040 (11)
C60.0400 (14)0.0450 (17)0.0367 (13)0.0085 (13)0.0066 (11)0.0018 (13)
C70.0388 (15)0.059 (2)0.0459 (16)0.0094 (14)0.0013 (13)0.0002 (15)
C80.0463 (16)0.063 (2)0.0398 (15)0.0029 (16)0.0075 (13)0.0010 (15)
C90.072 (2)0.054 (2)0.0334 (14)0.0040 (17)0.0015 (14)0.0114 (14)
C100.0502 (15)0.0382 (16)0.0402 (14)0.0102 (14)0.0089 (12)0.0017 (14)
C110.0335 (13)0.0340 (14)0.0281 (12)0.0014 (11)0.0082 (11)0.0020 (11)
C120.0281 (13)0.0404 (15)0.0335 (13)0.0030 (12)0.0057 (11)0.0062 (12)
C130.0242 (11)0.0404 (15)0.0304 (12)0.0045 (11)0.0037 (10)0.0105 (12)
C140.0336 (13)0.0448 (17)0.0359 (14)0.0009 (13)0.0097 (11)0.0079 (13)
C150.0431 (16)0.0410 (16)0.0362 (14)0.0035 (13)0.0094 (12)0.0003 (12)
C160.0271 (12)0.0394 (16)0.0403 (14)0.0044 (12)0.0022 (11)0.0101 (13)
C170.0312 (13)0.0447 (17)0.0499 (15)0.0052 (12)0.0122 (12)0.0109 (13)
C180.0322 (13)0.0438 (16)0.0412 (14)0.0019 (13)0.0141 (11)0.0044 (13)
C190.0358 (14)0.0401 (16)0.0500 (16)0.0021 (13)0.0031 (12)0.0103 (15)
C200.0460 (16)0.0429 (17)0.0593 (18)0.0005 (14)0.0023 (14)0.0079 (15)
N10.0270 (10)0.0392 (12)0.0294 (9)0.0004 (9)0.0070 (8)0.0067 (9)
O10.0333 (9)0.0650 (14)0.0383 (10)0.0015 (10)0.0059 (8)0.0214 (10)
O20.0325 (10)0.0970 (18)0.0426 (10)0.0018 (11)0.0134 (8)0.0239 (12)
O30.0350 (9)0.0568 (13)0.0323 (9)0.0019 (9)0.0098 (8)0.0099 (9)
Geometric parameters (Å, º) top
C1—N11.476 (3)C11—O31.210 (3)
C1—C41.510 (4)C11—N11.403 (3)
C1—C21.539 (3)C11—C121.519 (3)
C1—H11.000C12—C131.515 (4)
C2—O11.450 (3)C12—C191.525 (4)
C2—C51.507 (4)C12—H121.000
C2—H21.000C13—C141.385 (4)
C3—O21.195 (3)C13—C181.385 (3)
C3—O11.349 (3)C14—C151.381 (4)
C3—N11.382 (3)C14—H140.950
C4—H4A0.980C15—C161.386 (4)
C4—H4B0.980C15—H150.950
C4—H4C0.980C16—C171.381 (4)
C5—C61.377 (4)C16—C201.510 (4)
C5—C101.383 (4)C17—C181.382 (4)
C6—C71.388 (4)C17—H170.950
C6—H60.950C18—H180.950
C7—C81.365 (4)C19—H19A0.980
C7—H70.950C19—H19B0.980
C8—C91.377 (4)C19—H19C0.980
C8—H80.950C20—H20A0.980
C9—C101.389 (4)C20—H20B0.980
C9—H90.950C20—H20C0.980
C10—H100.950
N1—C1—C4111.9 (2)N1—C11—C12117.8 (2)
N1—C1—C299.08 (18)C13—C12—C11110.0 (2)
C4—C1—C2115.4 (2)C13—C12—C19111.2 (2)
N1—C1—H1110.0C11—C12—C19110.0 (2)
C4—C1—H1110.0C13—C12—H12108.5
C2—C1—H1110.0C11—C12—H12108.5
O1—C2—C5109.3 (2)C19—C12—H12108.5
O1—C2—C1103.90 (18)C14—C13—C18117.7 (3)
C5—C2—C1117.3 (2)C14—C13—C12121.0 (2)
O1—C2—H2108.7C18—C13—C12121.1 (2)
C5—C2—H2108.7C15—C14—C13121.3 (2)
C1—C2—H2108.7C15—C14—H14119.4
O2—C3—O1122.1 (2)C13—C14—H14119.4
O2—C3—N1129.5 (2)C14—C15—C16121.1 (3)
O1—C3—N1108.4 (2)C14—C15—H15119.4
C1—C4—H4A109.5C16—C15—H15119.4
C1—C4—H4B109.5C17—C16—C15117.5 (3)
H4A—C4—H4B109.5C17—C16—C20121.4 (3)
C1—C4—H4C109.5C15—C16—C20121.2 (3)
H4A—C4—H4C109.5C16—C17—C18121.7 (2)
H4B—C4—H4C109.5C16—C17—H17119.2
C6—C5—C10119.2 (2)C18—C17—H17119.2
C6—C5—C2118.1 (2)C17—C18—C13120.8 (3)
C10—C5—C2122.7 (2)C17—C18—H18119.6
C5—C6—C7120.7 (3)C13—C18—H18119.6
C5—C6—H6119.7C12—C19—H19A109.5
C7—C6—H6119.7C12—C19—H19B109.5
C8—C7—C6119.8 (3)H19A—C19—H19B109.5
C8—C7—H7120.1C12—C19—H19C109.5
C6—C7—H7120.1H19A—C19—H19C109.5
C7—C8—C9120.2 (3)H19B—C19—H19C109.5
C7—C8—H8119.9C16—C20—H20A109.5
C9—C8—H8119.9C16—C20—H20B109.5
C8—C9—C10120.1 (3)H20A—C20—H20B109.5
C8—C9—H9119.9C16—C20—H20C109.5
C10—C9—H9119.9H20A—C20—H20C109.5
C5—C10—C9119.9 (3)H20B—C20—H20C109.5
C5—C10—H10120.1C3—N1—C11127.54 (19)
C9—C10—H10120.1C3—N1—C1111.17 (19)
O3—C11—N1118.8 (2)C11—N1—C1120.77 (19)
O3—C11—C12123.4 (2)C3—O1—C2110.07 (18)
N1—C1—C2—O125.9 (2)C12—C13—C14—C15174.1 (2)
C4—C1—C2—O193.7 (2)C13—C14—C15—C160.1 (4)
N1—C1—C2—C5146.7 (2)C14—C15—C16—C171.2 (4)
C4—C1—C2—C527.0 (3)C14—C15—C16—C20179.1 (2)
O1—C2—C5—C6151.5 (2)C15—C16—C17—C180.9 (4)
C1—C2—C5—C690.6 (3)C20—C16—C17—C18179.4 (2)
O1—C2—C5—C1028.2 (4)C16—C17—C18—C130.5 (4)
C1—C2—C5—C1089.7 (3)C14—C13—C18—C171.5 (4)
C10—C5—C6—C72.7 (4)C12—C13—C18—C17173.8 (2)
C2—C5—C6—C7177.6 (3)O2—C3—N1—C112.4 (5)
C5—C6—C7—C80.8 (5)O1—C3—N1—C11178.6 (2)
C6—C7—C8—C91.3 (5)O2—C3—N1—C1169.2 (3)
C7—C8—C9—C101.3 (5)O1—C3—N1—C19.7 (3)
C6—C5—C10—C92.6 (4)O3—C11—N1—C3169.9 (3)
C2—C5—C10—C9177.7 (3)C12—C11—N1—C313.2 (4)
C8—C9—C10—C50.6 (5)O3—C11—N1—C11.0 (4)
O3—C11—C12—C1398.0 (3)C12—C11—N1—C1175.8 (2)
N1—C11—C12—C1378.7 (3)C4—C1—N1—C399.9 (3)
O3—C11—C12—C1924.8 (4)C2—C1—N1—C322.4 (3)
N1—C11—C12—C19158.5 (2)C4—C1—N1—C1172.5 (3)
C11—C12—C13—C1455.6 (3)C2—C1—N1—C11165.3 (2)
C19—C12—C13—C1466.6 (3)O2—C3—O1—C2171.9 (3)
C11—C12—C13—C18129.2 (2)N1—C3—O1—C29.0 (3)
C19—C12—C13—C18108.7 (3)C5—C2—O1—C3148.9 (2)
C18—C13—C14—C151.3 (4)C1—C2—O1—C322.9 (3)
 

Acknowledgements

We are grateful to the Royal Society and the University of London Central Research Fund for their financial support to JE, and the EPSRC National Mass Spectrometry Service (Swansea) for accurate mass determination.

References

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