(4S)-Benzyl 4-isopropyl-5-oxo-1,3-oxazolidine-3-carboxyl­ate

In the crystal structure of the title compound, C₁₄H₁₇NO₄, obtained by the reaction of N-benzoxycarbonyl-L-valine, paraformaldehyde and 4-methyl­benzene­sulfonic acid, mol­ecules are linked by C—H...O hydrogen bonds, generating linear chains parallel to the a axis. C—H...π inter­actions of stacked benzene rings also provide stability for the crystal structure.

Key indicators

• Single-crystal X-ray study
• T = 153 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.028
• wR factor = 0.063
• Data-to-parameter ratio = 8.0

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) .....       7.95
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C14 H17 N O4

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           25.00
           From the CIF: _reflns_number_total               1368
           Count of symmetry unique reflns         1379
           Completeness (_total/calc)             99.20%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C4     ...          S

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

The title compound (I) belongs to a class of 5-oxazolidinone and has been used to synthesize dipeptides and a series of biologically active molecules (Dorow & Gingrich, 1999).

In the compound, the oxazolidine ring is formed by the reaction of N-benzoxycarbonyl-L-valine, paraformaldehyde, and 4-methylbenzenesulfonic acid. The phenyl and the oxazolidine rings make a dihedral angle of 49.7 (1) (Fig. 1). The absolute configuration (S) of the stereocentre C4 remains unchanged during the synthetic procedure. An X-ray crystal structure determination of the molecular structure of compound (I) was carried out to determine its conformation. The bond lengths are within normal ranges (Allen et al., 1987).

The packing is shown in Fig. 2. The occurrence of C—H···O hydrogen bond interactions lead to the formation of linear chains parallel to the a axis. The packing is further stabilized by C—H···π interactions of stacked benzene rings in the chains (Fig. 3), with typical geometry (Pavel et al., 1993).

Related literature

For related literature, see: Dorow & Gingrich (1999); Allen et al. (1987); Pavel et al. (1993); Reddy et al. (2000).

S2. Experimental

The title compound was prepared by a method based on one described by Reddy et al. (2000). A mixture of N-benzoxycarbonyl-L-valine (7.53 g, 3 mmol), paraformaldehyde (1.8 g, 6 mmol) and 4-methylbenzenesulfonic acid (PTSA, 0.31 g, 1.8 mmol) in benzene (25 ml) was refluxed, using a Dean–Stark apparatus, for about 1 h. After cooling, the resulting mixture was washed with 0.3 M aqueous K₂CO₃ solution (30 ml) followed by saturated aqueous NaCl solution (30 ml). The organic layer was separated and dried with Mg₂SO₄, filtered and concentrated in vacuo to give the crude product as a white solid (5.12 g, 65%). Crystals suitable for X-ray diffraction were obtained from an ethanol solution.

S3. Refinement

The hydrogen atoms were positioned geometrically (C—H = 0.93, 0.98, 0.97 or 0.96 Å for phenyl, tertiary, methylene or methyl H atoms respectively) and were included in the refinement in the riding model approximation. The displacement parameters of methyl H atoms were set to 1.5U_eq(C), while those of other H atoms were set to 1.2U_eq(C).

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. The molecular structure of (I) with the atom-labeling scheme, showing 50% probability displacement ellipsoids. H atoms are drawn as spheres of arbitrary radius.
	Fig. 2. The packing of the molecules, viewed down the a axis.
	Fig. 3. C—H···π interactions of (I). These and hydrogen bonds are shown as dashed lines. [Symmetry codes: (i) x - 1/2, -y + 1/2, -z; (ii) x + 1/2, -y + 1/2, -z.]

(4S)-Benzyl 4-isopropyl-5-oxo-1,3-oxazolidine-3-carboxylate

Crystal data

C14H17NO4	F(000) = 560
Mr = 263.29	Dx = 1.317 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 2839 reflections
a = 6.0528 (2) Å	θ = 2.9–32.6°
b = 13.1581 (5) Å	µ = 0.10 mm^−1
c = 16.6778 (6) Å	T = 153 K
V = 1328.28 (8) Å^3	Needle, colourless
Z = 4	0.50 × 0.17 × 0.09 mm

Data collection

Bruker APEX CCD diffractometer	1368 independent reflections
Radiation source: sealed tube	1100 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.028
Detector resolution: 16.1903 pixels mm^-1	θmax = 25.0°, θmin = 2.9°
ϕ and ω scans	h = −7→7
Absorption correction: multi-scan (SADABS; Bruker, 2001)	k = −14→15
Tmin = 0.953, Tmax = 0.991	l = −19→19
5718 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.028	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.062	H-atom parameters constrained
S = 0.99	w = 1/[σ^2(Fo^2) + (0.0398P)^2] where P = (Fo^2 + 2Fc^2)/3
1368 reflections	(Δ/σ)max < 0.001
172 parameters	Δρmax = 0.12 e Å^−3
0 restraints	Δρmin = −0.13 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	−0.4445 (2)	−0.27913 (11)	0.18553 (8)	0.0312 (3)
C2	−0.6151 (3)	−0.24832 (15)	0.13165 (12)	0.0315 (5)
H2A	−0.7493	−0.2318	0.1607	0.038*
H2B	−0.6473	−0.3017	0.0932	0.038*
N3	−0.5269 (3)	−0.15900 (11)	0.09160 (9)	0.0250 (4)
C4	−0.3046 (3)	−0.13532 (13)	0.11905 (11)	0.0242 (4)
H4A	−0.2008	−0.1412	0.0742	0.029*
O5	−0.1002 (2)	−0.23774 (11)	0.21593 (8)	0.0361 (4)
C5	−0.2637 (3)	−0.22044 (15)	0.17824 (11)	0.0261 (4)
O6	−0.7800 (2)	−0.17466 (10)	−0.00699 (9)	0.0348 (4)
C6	−0.6135 (3)	−0.13483 (15)	0.01957 (12)	0.0268 (5)
O7	−0.4976 (2)	−0.06146 (10)	−0.01706 (7)	0.0308 (3)
C8	−0.5807 (4)	−0.02766 (16)	−0.09484 (11)	0.0325 (5)
H8A	−0.6570	−0.0837	−0.1206	0.039*
H8B	−0.4566	−0.0089	−0.1286	0.039*
C9	−0.7346 (4)	0.06079 (15)	−0.08858 (11)	0.0287 (5)
C10	−0.9408 (4)	0.05173 (17)	−0.05121 (12)	0.0361 (5)
H10A	−0.9819	−0.0099	−0.0283	0.043*
C11	−1.0833 (4)	0.13326 (18)	−0.04812 (13)	0.0435 (6)
H11A	−1.2181	0.1269	−0.0218	0.052*
C12	−1.0276 (4)	0.22421 (19)	−0.08374 (14)	0.0482 (6)
H12A	−1.1247	0.2790	−0.0821	0.058*
C13	−0.8260 (4)	0.23316 (17)	−0.12188 (15)	0.0467 (6)
H13A	−0.7882	0.2941	−0.1466	0.056*
C14	−0.6801 (4)	0.15252 (15)	−0.12363 (12)	0.0365 (5)
H14A	−0.5438	0.1600	−0.1487	0.044*
C15	−0.2829 (3)	−0.02961 (14)	0.15749 (11)	0.0266 (5)
H15A	−0.3376	0.0202	0.1186	0.032*
C16	−0.4247 (4)	−0.02032 (17)	0.23247 (13)	0.0378 (5)
H16A	−0.4075	0.0464	0.2550	0.057*
H16B	−0.3791	−0.0703	0.2710	0.057*
H16C	−0.5769	−0.0312	0.2187	0.057*
C17	−0.0424 (3)	−0.00377 (16)	0.17484 (13)	0.0375 (5)
H17A	−0.0338	0.0625	0.1988	0.056*
H17B	0.0401	−0.0043	0.1257	0.056*
H17C	0.0182	−0.0532	0.2110	0.056*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0307 (8)	0.0288 (7)	0.0341 (7)	−0.0021 (7)	0.0004 (6)	0.0064 (6)
C2	0.0256 (11)	0.0325 (12)	0.0363 (11)	−0.0034 (10)	0.0005 (9)	0.0050 (10)
N3	0.0244 (9)	0.0243 (8)	0.0261 (9)	−0.0028 (7)	−0.0006 (7)	0.0013 (7)
C4	0.0224 (10)	0.0257 (10)	0.0244 (10)	−0.0005 (9)	0.0020 (8)	0.0008 (9)
O5	0.0331 (8)	0.0374 (8)	0.0378 (8)	0.0059 (7)	−0.0048 (7)	0.0036 (7)
C5	0.0274 (11)	0.0248 (10)	0.0261 (10)	0.0032 (9)	0.0033 (10)	−0.0028 (9)
O6	0.0328 (8)	0.0344 (8)	0.0372 (8)	−0.0060 (7)	−0.0088 (7)	−0.0012 (7)
C6	0.0267 (11)	0.0232 (11)	0.0304 (11)	0.0002 (10)	0.0014 (9)	−0.0039 (9)
O7	0.0325 (8)	0.0313 (7)	0.0286 (7)	−0.0057 (7)	−0.0029 (6)	0.0055 (6)
C8	0.0396 (12)	0.0346 (11)	0.0232 (10)	−0.0033 (10)	−0.0023 (9)	0.0027 (9)
C9	0.0375 (12)	0.0298 (11)	0.0187 (9)	−0.0039 (10)	−0.0045 (9)	0.0003 (9)
C10	0.0414 (13)	0.0358 (12)	0.0310 (11)	−0.0023 (11)	0.0010 (10)	0.0037 (10)
C11	0.0388 (13)	0.0509 (15)	0.0408 (13)	0.0027 (13)	−0.0022 (11)	−0.0038 (12)
C12	0.0554 (17)	0.0377 (14)	0.0514 (14)	0.0107 (13)	−0.0094 (13)	−0.0075 (12)
C13	0.0624 (16)	0.0283 (12)	0.0493 (13)	−0.0039 (12)	−0.0102 (13)	0.0045 (12)
C14	0.0430 (13)	0.0360 (12)	0.0305 (11)	−0.0070 (11)	−0.0022 (10)	0.0017 (11)
C15	0.0299 (11)	0.0212 (10)	0.0288 (10)	0.0002 (9)	−0.0049 (9)	0.0012 (8)
C16	0.0353 (12)	0.0364 (12)	0.0419 (12)	0.0045 (10)	0.0002 (10)	−0.0116 (10)
C17	0.0365 (13)	0.0365 (13)	0.0395 (12)	−0.0090 (11)	−0.0019 (10)	−0.0004 (10)

Geometric parameters (Å, º)

O1—C5	1.345 (2)	C10—C11	1.378 (3)
O1—C2	1.428 (2)	C10—H10A	0.930
C2—N3	1.454 (2)	C11—C12	1.378 (4)
C2—H2A	0.970	C11—H11A	0.930
C2—H2B	0.970	C12—C13	1.381 (4)
N3—C6	1.349 (2)	C12—H12A	0.930
N3—C4	1.455 (2)	C13—C14	1.381 (3)
C4—C5	1.513 (3)	C13—H13A	0.930
C4—C15	1.537 (2)	C14—H14A	0.930
C4—H4A	0.980	C15—C16	1.522 (3)
O5—C5	1.194 (2)	C15—C17	1.523 (3)
O6—C6	1.219 (2)	C15—H15A	0.980
C6—O7	1.340 (2)	C16—H16A	0.960
O7—C8	1.461 (2)	C16—H16B	0.960
C8—C9	1.495 (3)	C16—H16C	0.960
C8—H8A	0.970	C17—H17A	0.960
C8—H8B	0.970	C17—H17B	0.960
C9—C14	1.381 (3)	C17—H17C	0.960
C9—C10	1.400 (3)
C5—O1—C2	111.63 (15)	C11—C10—H10A	119.7
O1—C2—N3	104.66 (15)	C9—C10—H10A	119.7
O1—C2—H2A	110.8	C10—C11—C12	120.5 (2)
N3—C2—H2A	110.8	C10—C11—H11A	119.8
O1—C2—H2B	110.8	C12—C11—H11A	119.8
N3—C2—H2B	110.8	C11—C12—C13	119.3 (2)
H2A—C2—H2B	108.9	C11—C12—H12A	120.4
C6—N3—C2	117.21 (16)	C13—C12—H12A	120.4
C6—N3—C4	126.09 (16)	C14—C13—C12	120.6 (2)
C2—N3—C4	111.61 (15)	C14—C13—H13A	119.7
N3—C4—C5	101.42 (15)	C12—C13—H13A	119.7
N3—C4—C15	113.81 (15)	C13—C14—C9	120.7 (2)
C5—C4—C15	112.56 (15)	C13—C14—H14A	119.7
N3—C4—H4A	109.6	C9—C14—H14A	119.7
C5—C4—H4A	109.6	C16—C15—C17	111.42 (17)
C15—C4—H4A	109.6	C16—C15—C4	111.55 (16)
O5—C5—O1	121.14 (18)	C17—C15—C4	111.28 (16)
O5—C5—C4	128.30 (19)	C16—C15—H15A	107.4
O1—C5—C4	110.55 (16)	C17—C15—H15A	107.4
O6—C6—O7	125.19 (18)	C4—C15—H15A	107.4
O6—C6—N3	122.92 (18)	C15—C16—H16A	109.5
O7—C6—N3	111.88 (17)	C15—C16—H16B	109.5
C6—O7—C8	116.37 (15)	H16A—C16—H16B	109.5
O7—C8—C9	112.93 (16)	C15—C16—H16C	109.5
O7—C8—H8A	109.0	H16A—C16—H16C	109.5
C9—C8—H8A	109.0	H16B—C16—H16C	109.5
O7—C8—H8B	109.0	C15—C17—H17A	109.5
C9—C8—H8B	109.0	C15—C17—H17B	109.5
H8A—C8—H8B	107.8	H17A—C17—H17B	109.5
C14—C9—C10	118.4 (2)	C15—C17—H17C	109.5
C14—C9—C8	120.14 (19)	H17A—C17—H17C	109.5
C10—C9—C8	121.37 (18)	H17B—C17—H17C	109.5
C11—C10—C9	120.6 (2)
C5—O1—C2—N3	−3.0 (2)	O6—C6—O7—C8	0.1 (3)
O1—C2—N3—C6	157.15 (15)	N3—C6—O7—C8	−178.52 (15)
O1—C2—N3—C4	0.8 (2)	C6—O7—C8—C9	92.1 (2)
C6—N3—C4—C5	−152.48 (17)	O7—C8—C9—C14	117.2 (2)
C2—N3—C4—C5	1.34 (19)	O7—C8—C9—C10	−66.2 (2)
C6—N3—C4—C15	86.4 (2)	C14—C9—C10—C11	−1.4 (3)
C2—N3—C4—C15	−119.80 (17)	C8—C9—C10—C11	−178.02 (19)
C2—O1—C5—O5	−176.54 (18)	C9—C10—C11—C12	1.8 (3)
C2—O1—C5—C4	4.0 (2)	C10—C11—C12—C13	−0.7 (4)
N3—C4—C5—O5	177.38 (19)	C11—C12—C13—C14	−0.8 (4)
C15—C4—C5—O5	−60.6 (3)	C12—C13—C14—C9	1.2 (3)
N3—C4—C5—O1	−3.20 (19)	C10—C9—C14—C13	−0.1 (3)
C15—C4—C5—O1	118.80 (17)	C8—C9—C14—C13	176.57 (19)
C2—N3—C6—O6	11.0 (3)	N3—C4—C15—C16	62.4 (2)
C4—N3—C6—O6	163.56 (17)	C5—C4—C15—C16	−52.3 (2)
C2—N3—C6—O7	−170.34 (15)	N3—C4—C15—C17	−172.49 (16)
C4—N3—C6—O7	−17.8 (2)	C5—C4—C15—C17	72.8 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2A···O5^i	0.97	2.32	3.258 (2)	163
C12—H12A···Cg^ii	0.93	3.37	3.963 (3)	124

Symmetry codes: (i) x−1, y, z; (ii) x−1/2, −y+1/2, −z.