Buy article online - an online subscription or single-article purchase is required to access this article.
Download citation
Download citation
link to html
The absolute configuration of the title compound, alter­natively called (+)-(4,5-di­hydro-2,5-di­phenyl­oxazol-4-yl)­methanol, C16H15NO2, has been confirmed as 4S,5S. The hydroxy­methyl group and phenyl ring at the asymmetric C atoms exhibit β and α orientations, respectively. The exocyclic C—C bonds at the asymmetric C atoms are mutually anticlinal (−ac). The hydroxyl group and the N atom of the oxazoline ring are involved in an intermolecular hydrogen bond leading to chains of mol­ecules.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270100006818/jz1397sup1.cif
Contains datablocks II, global

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S0108270100006818/jz1397IIsup2.hkl
Contains datablock II

CCDC reference: 150336

Comment top

The synthesis of the title compound, (II), from (1S,2S)-(+)-2-amino-1-phenyl-1,3-propanediol, (I), and ethyl benzimidate hydrochloride or benzonitrile has recently been reported independently by three research groups (Allen & Williams, 1994; Hoarau et al., 1997; Rozwadowska, 1998). Although the stereochemistry of (II) has been accepted as (4S,5S), the samples of oxazoline (II) prepared in these laboratories differed significantly in their physical data, i.e. in specific rotations, both in the sign and dimension, melting points and solubility, whereas the spectral data were much the same, within experimental error, for all the samples (see Experimental). \sch

Oxazoline (II), prepared in our laboratory from (I) and ethyl benzimidate hydrochloride or benzonitrile, showed positive rotation, as did the sample described by Hoarau et al. (1997), whereas Allen & Williams (1994) reported negative rotation. There were also differences in melting points for all the samples: our sample melted much higher (459–460 K) than the samples prepared by Allen & Williams (400–402 K) and Hoarau et al. (408 K) Moreover, we reported poor solubility of the compound in chloroform at room temperature. Since oxazolines are intermediates in the O N acyl group migration in acylated 1,2-aminoalcohols, involving in some cases inversion of configuration, we decided to confirm unambiguously the structure of oxazoline (II) of m.p. 459–460 K and [α]D20 = +51.0 (c = 0.54, CHCl3) by X-ray analysis.

For the (+)-enantiomer shown in Fig. 1, the tetrahedral C4 and C5 atoms are chiral centres. The absolute configuration of those atoms was established as 4S and 5S by the structure refinement using Bijvoet-pair reflections. The hydroxymethyl group at the asymmetric C4 atom exhibits a β-orientation, whereas the phenyl group at the asymmetric C5 atom is α-oriented. The torsion angle C12—C4—C5—C14 [−111.39 (13)°] indicates anti-clinal conformation of the C12 atom in the hydroxymethyl group with respect to the C14 atom of the phenyl group.

The oxazoline ring is nearly planar with the r.m.s. deviation of 0.0306 Å. The C2 and C5 phenyl groups subtend very different interplanar angles oxazoline ring of 8.82 (10) and 82.47 (4)° to this ring. The C2—C6 distance of 1.4723 (17) Å is shorter than the C5—C14 single bond 1.4999 (16) Å by about 12σ. This fact indicates a weak conjugation effect between the C2 phenyl group and the oxazoline ring.

The bond distances and angles in the title molecule are consistent with those found in (4S,5S,SS)-4-hydroxymethyl-2-[2-(4-methylphenylsulfinyl)phenyl]- 4,5-dihydro-5-phenyl-1,3-oxazole (Bower et al., 1996). Other hydroxymethyl-phenyloxazoline derivatives are not described in the Cambridge Structural Database, Version 518 (Allen & Kennard, 1993).

The O13 atom of the hydroxyl group is syn-clinal with respect to the N3—C4 bond of the oxazoline ring [torsion angle O13—C12—C4—N3 68.15 (14)°]. We assume that this arrangement of the O13 atom is stabilized by the intermolecular hydrogen bond O13—H13A···N3i (Table 2), which leads to chains of molecules parallel to the x axis. An intermolecular C16—H16A···O13ii contact (Table 2) links neighbouring chains into a two-dimensional hydrogen network parallel to the xy plane (Fig. 2).

Experimental top

The title compound, (II), was prepared according to the literature (Rozwadowska, 1998). Some of physical and spectral characteristics of our sample and of the othersare given below:

Our sample: m.p. 459–460 K; [α]D20 = +51,0 (c = 0,54, CHCl3), [α]D20 = +70,0 (c = 0,5, CH3OH),[α]D20 = +88,5 (c = 1,0, DMSO); IR (KBr) cm−1: 1648 (CN); 1H NMR (CDCl3): δ = 4,24 (d, J = 8,0 Hz, H4), 5,58 (d, J = 8,2 Hz, H5).

Allen & Williams (1994): m.p. 400–402 K; [α]D25 = −44,6 (c = 5,4, CHCl3); IR (KBr) cm−1: 1670 (CN); 1H NMR (CDCl3): δ = 4,22 (H4), 5,56 (d, J = 8,0 Hz, H5).

Hoarau et al. (1997): m.p. 408 K; [α]D20 = +74,2 (c = 1,0, DMSO); 1H NMR (CDCl3): δ = 4,23 (d, J = 8,1 Hz, H4), 5,57 (d, J = 8,1 Hz, H5).

Refinement top

The crystals were grown from ethanol by slow evaporation of the solvent at room temperature. The positions of the H atoms were obtained from difference Fourier maps and refined freely. The absolute configuration of (II) was established on the basis of 930 Friedel opposite reflections using the Flack parameter (Flack 1983).

Computing details top

Data collection: Kuma KM-4 Software (Kuma Diffraction, 1991); cell refinement: Kuma KM-4 Software; data reduction: Kuma KM-4 Software; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEPII (Johnson, 1976) and ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97.

Figures top
[Figure 1] Fig. 1. Molecular structure of (II); displacement ellipsoids are drawn at the 50% probability level; H atoms, treated as isotropic, are on an arbitrary scale.
[Figure 2] Fig. 2. Hydrogen bonding in the crystal lattice of (II). The hydrogen bonds are indicated with dashed lines; the symmetry codes are explained in Table 2.
(4S,5S)-(+)-4-Hydroxymethyl-2,5-diphenyloxazoline top
Crystal data top
C16H15NO2Dx = 1.272 Mg m3
Mr = 253.29Melting point: 459–460 K K
Orthorhombic, P212121Cu Kα radiation, λ = 1.54178 Å
a = 4.8995 (10) ÅCell parameters from 48 reflections
b = 11.3300 (13) Åθ = 15.4–30.3°
c = 23.820 (3) ŵ = 0.67 mm1
V = 1322.3 (4) Å3T = 293 K
Z = 4Needle, colourless
F(000) = 5360.50 × 0.25 × 0.11 mm
Data collection top
Kuma Diffraction KM-4
diffractometer
Rint = 0.037
Radiation source: fine-focus sealed tubeθmax = 70.0°, θmin = 3.7°
Graphite monochromatorh = 55
ω–2θ scansk = 013
2557 measured reflectionsl = 029
2406 independent reflections2 standard reflections every 100 reflections
2273 reflections with I > 2σ(I) intensity decay: 0.7%
Refinement top
Refinement on F2Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: fullAll H-atom parameters refined
R[F2 > 2σ(F2)] = 0.029 w = 1/[σ2(Fo2) + (0.0536P)2 + 0.0663P]
where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.082(Δ/σ)max < 0.001
S = 1.08Δρmax = 0.13 e Å3
2406 reflectionsΔρmin = 0.13 e Å3
233 parametersExtinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraintsExtinction coefficient: 0.0047 (7)
Primary atom site location: structure-invariant direct methodsAbsolute structure: Flack (1983)
Secondary atom site location: difference Fourier mapAbsolute structure parameter: 0.09 (19)
Crystal data top
C16H15NO2V = 1322.3 (4) Å3
Mr = 253.29Z = 4
Orthorhombic, P212121Cu Kα radiation
a = 4.8995 (10) ŵ = 0.67 mm1
b = 11.3300 (13) ÅT = 293 K
c = 23.820 (3) Å0.50 × 0.25 × 0.11 mm
Data collection top
Kuma Diffraction KM-4
diffractometer
Rint = 0.037
2557 measured reflections2 standard reflections every 100 reflections
2406 independent reflections intensity decay: 0.7%
2273 reflections with I > 2σ(I)
Refinement top
R[F2 > 2σ(F2)] = 0.029All H-atom parameters refined
wR(F2) = 0.082Δρmax = 0.13 e Å3
S = 1.08Δρmin = 0.13 e Å3
2406 reflectionsAbsolute structure: Flack (1983)
233 parametersAbsolute structure parameter: 0.09 (19)
0 restraints
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
xyzUiso*/Ueq
O10.6153 (2)0.95123 (7)0.12135 (4)0.0560 (3)
C20.6976 (3)0.83793 (10)0.11417 (5)0.0446 (3)
N30.8497 (2)0.81512 (8)0.07251 (4)0.0454 (2)
C40.8914 (3)0.92531 (9)0.04140 (5)0.0428 (3)
C50.7121 (3)1.01667 (10)0.07262 (5)0.0428 (3)
C60.5973 (3)0.75357 (11)0.15641 (5)0.0482 (3)
C70.6979 (4)0.63901 (13)0.15754 (6)0.0619 (4)
C80.5996 (5)0.55956 (15)0.19670 (7)0.0739 (5)
C90.4053 (5)0.59340 (17)0.23446 (7)0.0761 (5)
C100.3007 (5)0.70634 (19)0.23316 (7)0.0789 (5)
C110.3980 (4)0.78668 (15)0.19443 (6)0.0630 (4)
C120.8116 (3)0.91222 (11)0.01947 (6)0.0512 (3)
O130.5259 (2)0.89721 (9)0.02506 (5)0.0592 (3)
C140.8498 (3)1.12880 (9)0.09044 (5)0.0409 (3)
C150.7732 (3)1.23437 (11)0.06599 (6)0.0543 (3)
C160.9014 (4)1.33881 (12)0.08107 (7)0.0681 (4)
C171.1019 (4)1.33838 (13)0.12064 (7)0.0663 (4)
C181.1794 (4)1.23448 (15)0.14528 (7)0.0656 (4)
C191.0548 (3)1.12933 (12)0.13020 (6)0.0541 (3)
H4A1.092 (4)0.9450 (13)0.0443 (6)0.053 (4)*
H5A0.559 (3)1.0366 (13)0.0502 (6)0.046 (4)*
H7A0.843 (5)0.6148 (17)0.1319 (8)0.083 (6)*
H8A0.679 (5)0.476 (2)0.1952 (9)0.099 (7)*
H9A0.341 (5)0.5391 (18)0.2623 (9)0.087 (6)*
H10A0.166 (5)0.730 (2)0.2613 (9)0.105 (7)*
H11A0.313 (5)0.8696 (19)0.1932 (8)0.088 (6)*
H12A0.869 (4)0.9860 (16)0.0401 (7)0.065 (4)*
H12B0.921 (4)0.8417 (15)0.0357 (7)0.064 (5)*
H13A0.492 (5)0.826 (2)0.0419 (8)0.092 (7)*
H15A0.630 (4)1.2322 (15)0.0377 (7)0.073 (5)*
H16A0.844 (4)1.4148 (17)0.0645 (8)0.076 (5)*
H17A1.193 (5)1.4129 (18)0.1314 (8)0.088 (6)*
H18A1.317 (5)1.2351 (17)0.1740 (8)0.081 (5)*
H19A1.099 (4)1.0573 (17)0.1490 (7)0.069 (5)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0609 (6)0.0336 (4)0.0735 (6)0.0047 (4)0.0270 (5)0.0076 (4)
C20.0460 (7)0.0348 (5)0.0529 (6)0.0034 (5)0.0014 (5)0.0072 (5)
N30.0509 (6)0.0346 (5)0.0508 (5)0.0060 (4)0.0020 (5)0.0022 (4)
C40.0403 (7)0.0311 (5)0.0572 (7)0.0014 (4)0.0065 (5)0.0049 (4)
C50.0396 (6)0.0322 (5)0.0565 (6)0.0015 (4)0.0058 (5)0.0054 (5)
C60.0529 (7)0.0438 (6)0.0480 (6)0.0089 (5)0.0032 (5)0.0035 (5)
C70.0792 (11)0.0470 (7)0.0594 (7)0.0003 (7)0.0041 (8)0.0032 (6)
C80.1008 (14)0.0525 (8)0.0684 (9)0.0056 (9)0.0036 (9)0.0118 (7)
C90.0919 (13)0.0748 (11)0.0616 (9)0.0196 (10)0.0004 (8)0.0186 (8)
C100.0837 (13)0.0876 (12)0.0654 (9)0.0072 (11)0.0170 (9)0.0119 (8)
C110.0668 (10)0.0610 (8)0.0613 (8)0.0027 (7)0.0093 (7)0.0026 (6)
C120.0595 (8)0.0411 (6)0.0531 (7)0.0008 (6)0.0102 (6)0.0003 (5)
O130.0625 (6)0.0420 (5)0.0731 (6)0.0008 (4)0.0130 (5)0.0125 (4)
C140.0420 (6)0.0319 (5)0.0488 (5)0.0015 (5)0.0070 (5)0.0049 (4)
C150.0572 (8)0.0389 (6)0.0667 (8)0.0016 (5)0.0018 (7)0.0042 (5)
C160.0789 (11)0.0341 (6)0.0912 (11)0.0052 (7)0.0067 (9)0.0042 (6)
C170.0693 (10)0.0472 (7)0.0825 (9)0.0198 (7)0.0136 (8)0.0158 (7)
C180.0586 (9)0.0698 (9)0.0684 (8)0.0146 (8)0.0029 (8)0.0152 (7)
C190.0526 (8)0.0470 (7)0.0627 (7)0.0004 (6)0.0041 (6)0.0006 (6)
Geometric parameters (Å, º) top
O1—C21.3563 (14)C10—C111.381 (2)
O1—C51.4568 (16)C10—H10A0.98 (2)
C2—N31.2677 (16)C11—H11A1.03 (2)
C2—C61.4723 (17)C12—O131.4163 (19)
N3—C41.4660 (15)C12—H12A1.010 (18)
C4—C121.5090 (19)C12—H12B1.037 (18)
C4—C51.5479 (16)O13—H13A0.92 (2)
C4—H4A1.011 (17)C14—C191.3806 (19)
C5—C141.4999 (16)C14—C151.3822 (17)
C5—H5A0.949 (16)C15—C161.387 (2)
C6—C111.383 (2)C15—H15A0.974 (18)
C6—C71.389 (2)C16—C171.361 (3)
C7—C81.383 (2)C16—H16A0.99 (2)
C7—H7A0.98 (2)C17—C181.369 (3)
C8—C91.365 (3)C17—H17A0.99 (2)
C8—H8A1.02 (2)C18—C191.386 (2)
C9—C101.379 (3)C18—H18A0.96 (2)
C9—H9A0.96 (2)C19—H19A0.955 (19)
C2—O1—C5106.52 (9)C9—C10—H10A119.6 (14)
N3—C2—O1117.81 (10)C11—C10—H10A120.4 (14)
N3—C2—C6126.79 (11)C10—C11—C6120.14 (16)
O1—C2—C6115.40 (10)C10—C11—H11A118.9 (12)
C2—N3—C4107.69 (9)C6—C11—H11A120.9 (11)
N3—C4—C12111.46 (10)O13—C12—C4110.98 (11)
N3—C4—C5104.34 (10)O13—C12—H12A109.3 (11)
C12—C4—C5112.35 (11)C4—C12—H12A108.3 (9)
N3—C4—H4A106.8 (8)O13—C12—H12B112.5 (10)
C12—C4—H4A109.9 (8)C4—C12—H12B107.5 (9)
C5—C4—H4A111.8 (9)H12A—C12—H12B108.1 (13)
O1—C5—C14110.61 (10)C12—O13—H13A108.9 (15)
O1—C5—C4103.13 (9)C19—C14—C15118.86 (12)
C14—C5—C4116.55 (10)C19—C14—C5121.68 (11)
O1—C5—H5A108.2 (9)C15—C14—C5119.45 (12)
C14—C5—H5A108.3 (9)C14—C15—C16120.42 (14)
C4—C5—H5A109.8 (9)C14—C15—H15A117.7 (11)
C11—C6—C7119.43 (13)C16—C15—H15A121.9 (11)
C11—C6—C2120.46 (12)C17—C16—C15120.19 (14)
C7—C6—C2120.10 (12)C17—C16—H16A119.1 (12)
C8—C7—C6119.86 (16)C15—C16—H16A120.7 (12)
C8—C7—H7A119.5 (11)C16—C17—C18120.01 (13)
C6—C7—H7A120.6 (11)C16—C17—H17A120.2 (13)
C9—C8—C7120.31 (17)C18—C17—H17A119.8 (13)
C9—C8—H8A123.2 (14)C17—C18—C19120.37 (16)
C7—C8—H8A116.5 (14)C17—C18—H18A119.6 (12)
C8—C9—C10120.33 (16)C19—C18—H18A120.0 (12)
C8—C9—H9A120.4 (12)C14—C19—C18120.14 (14)
C10—C9—H9A119.2 (13)C14—C19—H19A118.8 (12)
C9—C10—C11119.91 (18)C18—C19—H19A120.9 (12)
C5—O1—C2—N35.53 (16)C7—C8—C9—C101.4 (3)
C5—O1—C2—C6174.27 (11)C8—C9—C10—C111.7 (3)
O1—C2—N3—C41.09 (16)C9—C10—C11—C61.0 (3)
C6—C2—N3—C4178.69 (12)C7—C6—C11—C100.1 (2)
C2—N3—C4—C12125.02 (12)C2—C6—C11—C10178.62 (15)
C2—N3—C4—C53.54 (14)N3—C4—C12—O1368.15 (14)
C2—O1—C5—C14132.27 (11)C5—C4—C12—O1348.55 (14)
C2—O1—C5—C46.95 (13)O1—C5—C14—C1951.81 (15)
N3—C4—C5—O16.35 (13)C4—C5—C14—C1965.53 (16)
C12—C4—C5—O1127.24 (11)O1—C5—C14—C15129.16 (13)
N3—C4—C5—C14127.72 (11)C4—C5—C14—C15113.50 (14)
C12—C4—C5—C14111.39 (13)C19—C14—C15—C160.3 (2)
N3—C2—C6—C11169.62 (14)C5—C14—C15—C16178.78 (13)
O1—C2—C6—C1110.16 (19)C14—C15—C16—C170.8 (3)
N3—C2—C6—C78.9 (2)C15—C16—C17—C180.6 (3)
O1—C2—C6—C7171.30 (13)C16—C17—C18—C190.0 (3)
C11—C6—C7—C80.4 (2)C15—C14—C19—C180.4 (2)
C2—C6—C7—C8178.91 (15)C5—C14—C19—C18179.39 (13)
C6—C7—C8—C90.4 (3)C17—C18—C19—C140.5 (2)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O13—H13A···N3i0.92 (2)1.89 (2)2.7948 (14)169 (2)
C16—H16A···O13ii0.99 (2)2.49 (2)3.3314 (18)142.3 (16)
C5—H5A···O130.949 (16)2.394 (14)2.8419 (16)108.5 (11)
Symmetry codes: (i) x1/2, y+3/2, z; (ii) x+1/2, y+5/2, z.

Experimental details

Crystal data
Chemical formulaC16H15NO2
Mr253.29
Crystal system, space groupOrthorhombic, P212121
Temperature (K)293
a, b, c (Å)4.8995 (10), 11.3300 (13), 23.820 (3)
V3)1322.3 (4)
Z4
Radiation typeCu Kα
µ (mm1)0.67
Crystal size (mm)0.50 × 0.25 × 0.11
Data collection
DiffractometerKuma Diffraction KM-4
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
2557, 2406, 2273
Rint0.037
(sin θ/λ)max1)0.610
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.029, 0.082, 1.08
No. of reflections2406
No. of parameters233
H-atom treatmentAll H-atom parameters refined
Δρmax, Δρmin (e Å3)0.13, 0.13
Absolute structureFlack (1983)
Absolute structure parameter0.09 (19)

Computer programs: Kuma KM-4 Software (Kuma Diffraction, 1991), Kuma KM-4 Software, SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), ORTEPII (Johnson, 1976) and ORTEP-3 for Windows (Farrugia, 1997), SHELXL97.

Selected geometric parameters (Å, º) top
O1—C21.3563 (14)N3—C41.4660 (15)
O1—C51.4568 (16)C4—C51.5479 (16)
C2—N31.2677 (16)C5—C141.4999 (16)
C2—C61.4723 (17)
C2—O1—C5106.52 (9)N3—C4—C5104.34 (10)
N3—C2—O1117.81 (10)O1—C5—C4103.13 (9)
C2—N3—C4107.69 (9)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O13—H13A···N3i0.92 (2)1.89 (2)2.7948 (14)169 (2)
C16—H16A···O13ii0.99 (2)2.49 (2)3.3314 (18)142.3 (16)
Symmetry codes: (i) x1/2, y+3/2, z; (ii) x+1/2, y+5/2, z.
 

Subscribe to Acta Crystallographica Section C: Structural Chemistry

The full text of this article is available to subscribers to the journal.

If you have already registered and are using a computer listed in your registration details, please email support@iucr.org for assistance.

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.
E-mail address* 
Repeat e-mail address* 
(for error checking) 

Format*   PDF (US $40)
   HTML (US $40)
   PDF+HTML (US $50)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number 
(non-UK EC countries only) 
Country* 
 

Terms and conditions of use
Contact us

Follow Acta Cryst. C
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds