(2S,4R)-4-Ammonio-5-oxopyrrolidine-2-carboxylate.

In the crystal structure of the title compound, C(5)H(8)N(2)O(3), the mol-ecules exist in the zwitterionic form. The pyrrolidine ring adopts an envelope conformation with the unsubstituted endocyclic C atom situated at the flap. The other four endocyclic atoms are coplanar with the exocyclic carbonyl O atom, with an r.m.s. deviation from the mean plane of 0.06 Å. The carboxyl-ate substituent is located axially, while the ammonium group occupies an equatorial position. In the crystal structure, the mol-ecules are linked through N-H⋯O hydrogen bonds, forming a three-dimensional network.

Related literature

For mol­ecular recognition in N-methyl amino acids and proline residues, see: Dugave & Demange (2003 ▶). For the construction of modified amino acids, see: Dumy et al. (1997 ▶); Keller et al. (1998 ▶); Mutter et al. (1999 ▶); Tuchscherer & Mutter (2001 ▶); Paul et al. (1992 ▶). For pyroglutamic acid derivatives, see: Zabrocki et al. (1988 ▶); Kaczmarek et al. (2005 ▶). For the preparation of the title compound, see: Kaczmarek et al. (2001 ▶); Kaczmarek (2009 ▶). For asymmetry parameters, see: Griffin et al. (1984 ▶).

Experimental

Crystal data

C5H8N2O3

M = 144.13

Orthorhombic,

a = 5.9790 (3) Å

b = 9.3665 (4) Å

c = 11.3809 (5) Å

V = 637.36 (5) Å3

Z = 4

Cu Kα radiation

μ = 1.08 mm−1

T = 293 K

0.40 × 0.40 × 0.10 mm

Data collection

Bruker SMART APEX diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2003 ▶) T min = 0.707, T max = 0.900

7227 measured reflections

1169 independent reflections

1168 reflections with I > 2σ(I)

R int = 0.030

Refinement

R[F 2 > 2σ(F 2)] = 0.027

wR(F 2) = 0.069

S = 1.08

1169 reflections

125 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.13 e Å−3

Δρmin = −0.17 e Å−3

Absolute structure: Flack (1983 ▶), 461 Friedel pairs

Flack parameter: 0.1 (2)

Data collection: SMART (Bruker, 2003 ▶); cell refinement: SAINT-Plus (Bruker, 2003 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL and Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: SHELXTL and publCIF (Westrip, 2010 ▶).

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536810004277/bt5187sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810004277/bt5187Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C5H8N2O3	Dx = 1.502 Mg m−3
Mr = 144.13	Melting point: 423(2) K
Orthorhombic, P212121	Cu Kα radiation, λ = 1.54178 Å
Hall symbol: P 2ac 2ab	Cell parameters from 7056 reflections
a = 5.9790 (3) Å	θ = 6.1–70.8°
b = 9.3665 (4) Å	µ = 1.08 mm−1
c = 11.3809 (5) Å	T = 293 K
V = 637.36 (5) Å3	Prism, colourless
Z = 4	0.40 × 0.40 × 0.10 mm
F(000) = 304

Bruker SMART APEX diffractometer	1169 independent reflections
Radiation source: fine-focus sealed tube	1168 reflections with I > 2σ(I)
graphite	Rint = 0.030
ω scans	θmax = 70.8°, θmin = 6.1°
Absorption correction: multi-scan (SADABS; Bruker, 2003)	h = −6→5
Tmin = 0.707, Tmax = 0.900	k = −11→11
7227 measured reflections	l = −13→13

Refinement on F2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F2 > 2σ(F2)] = 0.027	w = 1/[σ2(Fo2) + (0.0468P)2 + 0.0681P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.069	(Δ/σ)max < 0.001
S = 1.08	Δρmax = 0.13 e Å−3
1169 reflections	Δρmin = −0.17 e Å−3
125 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraints	Extinction coefficient: 0.047 (3)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 461 Friedel pairs
Secondary atom site location: difference Fourier map	Flack parameter: 0.1 (2)

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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.

	x	y	z	Uiso*/Ueq
O1	0.85679 (17)	−0.10762 (9)	0.57781 (8)	0.0373 (3)
H2	0.838 (4)	0.3509 (18)	0.9130 (15)	0.042 (4)*
O2	0.57914 (17)	0.04638 (10)	0.55325 (8)	0.0383 (3)
O3	0.6519 (2)	0.46234 (9)	0.68254 (10)	0.0469 (3)
N1	0.8566 (2)	0.27436 (11)	0.61237 (10)	0.0353 (3)
H1	0.917 (4)	0.3094 (19)	0.5549 (17)	0.054 (5)*
C1	0.7725 (2)	0.01571 (13)	0.58351 (10)	0.0283 (3)
C5	0.9163 (2)	0.12935 (13)	0.64357 (11)	0.0304 (3)
H51	1.078 (3)	0.1140 (16)	0.6258 (13)	0.032 (4)*
C4	0.8646 (3)	0.12504 (13)	0.77672 (11)	0.0340 (3)
H41	0.807 (3)	0.0354 (17)	0.8009 (15)	0.045 (5)*
H42	0.995 (4)	0.156 (2)	0.8147 (18)	0.056 (5)*
C3	0.6848 (2)	0.23810 (12)	0.79144 (11)	0.0297 (3)
H31	0.541 (3)	0.1976 (15)	0.7877 (14)	0.030 (4)*
N2	0.7038 (2)	0.31400 (11)	0.90532 (10)	0.0310 (3)
H4	0.607 (3)	0.3822 (18)	0.9140 (14)	0.036 (4)*
H3	0.695 (3)	0.249 (2)	0.9630 (14)	0.042 (4)*
C2	0.7255 (2)	0.34135 (13)	0.68928 (11)	0.0319 (3)

	U11	U22	U33	U12	U13	U23
O1	0.0425 (6)	0.0262 (4)	0.0432 (5)	0.0027 (4)	−0.0079 (4)	−0.0062 (4)
O2	0.0334 (6)	0.0347 (5)	0.0466 (5)	−0.0016 (4)	−0.0093 (4)	0.0089 (4)
O3	0.0561 (7)	0.0309 (5)	0.0536 (6)	0.0133 (5)	0.0046 (5)	0.0104 (4)
N1	0.0451 (7)	0.0234 (5)	0.0374 (6)	−0.0044 (5)	0.0072 (5)	0.0050 (4)
C1	0.0331 (7)	0.0267 (6)	0.0251 (5)	−0.0021 (4)	0.0001 (5)	0.0034 (4)
C5	0.0311 (7)	0.0241 (6)	0.0361 (6)	−0.0008 (5)	0.0004 (5)	0.0004 (5)
C4	0.0435 (8)	0.0250 (6)	0.0335 (6)	0.0040 (5)	−0.0074 (6)	0.0002 (5)
C3	0.0294 (7)	0.0257 (5)	0.0340 (6)	−0.0027 (5)	−0.0020 (4)	0.0037 (5)
N2	0.0327 (7)	0.0257 (5)	0.0345 (5)	0.0022 (5)	0.0027 (4)	0.0029 (4)
C2	0.0321 (7)	0.0270 (6)	0.0367 (6)	−0.0015 (5)	−0.0022 (5)	0.0044 (5)

O1—C1	1.2621 (16)	C4—C3	1.5187 (19)
O2—C1	1.2399 (17)	C4—H41	0.949 (17)
O3—C2	1.2179 (16)	C4—H42	0.94 (2)
N1—C2	1.3321 (17)	C3—N2	1.4826 (16)
N1—C5	1.4485 (15)	C3—C2	1.5318 (16)
N1—H1	0.82 (2)	C3—H31	0.939 (17)
C1—C5	1.5295 (17)	N2—H2	0.88 (2)
C5—C4	1.5470 (17)	N2—H4	0.867 (18)
C5—H51	0.997 (17)	N2—H3	0.898 (18)
C2—N1—C5	115.19 (10)	C3—C4—H41	109.0 (11)
O3—C2—N1	127.55 (12)	C5—C4—H41	112.3 (10)
O3—C2—C3	125.30 (12)	C3—C4—H42	108.7 (13)
N1—C2—C3	107.15 (11)	C5—C4—H42	106.1 (13)
N1—C5—C1	113.86 (10)	H41—C4—H42	116.4 (17)
N1—C5—C4	102.44 (10)	N2—C3—C4	112.11 (10)
C1—C5—C4	107.90 (10)	N2—C3—C2	110.40 (10)
C3—C4—C5	103.37 (10)	N2—C3—H31	107.7 (9)
C4—C3—C2	104.12 (10)	C4—C3—H31	111.1 (9)
C2—N1—H1	126.6 (13)	C2—C3—H31	111.5 (9)
C5—N1—H1	117.8 (13)	C3—N2—H2	110.3 (11)
O2—C1—O1	124.76 (12)	C3—N2—H4	113.6 (11)
O2—C1—C5	119.14 (11)	H2—N2—H4	107.9 (16)
O1—C1—C5	115.82 (11)	C3—N2—H3	108.0 (11)
N1—C5—H51	108.9 (9)	H2—N2—H3	104.4 (16)
C1—C5—H51	110.7 (9)	H4—N2—H3	112.3 (15)
C4—C5—H51	112.9 (8)
N1—C5—C4—C3	26.38 (13)	O2—C1—C5—N1	−26.96 (16)
C5—C4—C3—C2	−25.98 (13)	O1—C1—C5—N1	158.87 (11)
C5—N1—C2—O3	−179.48 (14)	O2—C1—C5—C4	86.02 (13)
C5—N1—C2—C3	1.41 (16)	O1—C1—C5—C4	−88.15 (13)
C4—C3—C2—N1	16.23 (14)	C1—C5—C4—C3	−94.06 (11)
C4—C3—C2—O3	−162.91 (14)	C5—C4—C3—N2	−145.33 (10)
C2—N1—C5—C4	−17.99 (15)	N2—C3—C2—O3	−42.41 (18)
C2—N1—C5—C1	98.23 (14)	N2—C3—C2—N1	136.73 (12)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O2i	0.82 (2)	2.07 (2)	2.8535 (15)	161.2 (18)
N2—H2···O1ii	0.88 (2)	1.87 (2)	2.7346 (16)	168.5 (17)
N2—H3···O1iii	0.897 (17)	1.886 (17)	2.7788 (14)	173.4 (17)
N2—H4···O2iv	0.868 (17)	1.935 (17)	2.7967 (15)	172.3 (17)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O2i	0.82 (2)	2.07 (2)	2.8535 (15)	161.2 (18)
N2—H2⋯O1ii	0.88 (2)	1.87 (2)	2.7346 (16)	168.5 (17)
N2—H3⋯O1iii	0.897 (17)	1.886 (17)	2.7788 (14)	173.4 (17)
N2—H4⋯O2iv	0.868 (17)	1.935 (17)	2.7967 (15)	172.3 (17)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .