(6R,7R)-3-Hydroxymethyl-7-(2-phenyl­acetamido)-3-cephem-4-carboxylic acid lactone

Xiao-Liang Zhou; Hao Wang; Yan Wang; Pei-Ji Shi

doi:10.1107/S1600536811043881

. 2011 Oct 29;67(Pt 11):o3101. doi: 10.1107/S1600536811043881

(6R,7R)-3-Hydroxymethyl-7-(2-phenylacetamido)-3-cephem-4-carboxylic acid lactone

Xiao-Liang Zhou ^a,^*, Hao Wang ^a, Yan Wang ^a, Pei-Ji Shi ^a

PMCID: PMC3247487 PMID: 22220105

Abstract

In the title compound {systematic name: N-[(4R,5R)-3,11-dioxo-10-oxa-6-thia-2-azatricyclo[6.3.0.0^2,5]undec-1(8)-en-4-yl]-2-phenylacetamide}, C₁₆H₁₄N₂O₄S, the four- and five-membered rings adopt planar conformations (with r.m.s. deviations of 0.0349 and 0.0108 Å respectively) while the six-membered ring adopts a half-chair, or envelope-like, conformation with the S atom in the flap position. In the crystal, molecules are linked by N—H⋯O hydrogen bonds.

Related literature

For standard bond lengths, see: Allen et al. (1987 ▶) and for ring puckering parameters, see: Cremer & Pople (1975 ▶). The title compound is an important synthetic intermediate for cephalosporins. For its synthesis, see: Yu et al. (2009 ▶).

Experimental

Crystal data

C₁₆H₁₄N₂O₄S
M _r = 330.35
Orthorhombic,
a = 9.1300 (13) Å
b = 9.7060 (14) Å
c = 16.701 (2) Å
V = 1480.0 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.24 mm⁻¹
T = 113 K
0.26 × 0.24 × 0.22 mm

Data collection

Rigaku Saturn724 CCD diffractometer
Absorption correction: multi-scan (CrystalClear-SM Expert; Rigaku, 2009 ▶) T _min = 0.940, T _max = 0.949
21123 measured reflections
4249 independent reflections
3823 reflections with I > 2σ(I)
R _int = 0.043

Refinement

R[F ² > 2σ(F ²)] = 0.027
wR(F ²) = 0.065
S = 1.02
4249 reflections
213 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.29 e Å⁻³
Absolute structure: Flack (1983 ▶), 1803 Friedel pairs
Flack parameter: −0.02 (4)

Data collection: CrystalClear-SM Expert (Rigaku, 2009 ▶); cell refinement: CrystalClear-SM Expert; data reduction: CrystalClear-SM Expert; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: CrystalStructure (Rigaku, 2009 ▶); software used to prepare material for publication: CrystalStructure.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811043881/zj2026sup1.cif

e-67-o3101-sup1.cif^{(20KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811043881/zj2026Isup2.hkl

e-67-o3101-Isup2.hkl^{(208.2KB, hkl)}

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

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H1⋯O4ⁱ	0.778 (15)	2.276 (15)	3.0506 (14)	173.5 (14)

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors acknowledge financial support from the Institute of Radiation Medicine, Chinese Academy of Medical Sciences (No. SF1002).

supplementary crystallographic information

Comment

The title compound is a lactone derivative of cephalosporin, which was fond originally as an impurity in the synthetic process, but now has become an useful intermediate, because the lactone ring enhances the stability of the molecule and adds new sites for structure reformation.There is one molecule in the asymmetric unit of the title compound. The absolute configuration has been determined by refinement of the Flack parameter (Flack, 1983) which converged to -0.02 (4). The ring A (N1—C1—C2—C3) and ring C (C4—C5—O3—C6—C7) adopt planer conformation with the r.m.s. deviation were 0.0349 and 0.0108 respectively, the ring B (S1—C3—N1—C4—C7—C8) displays half chair conformation with atom S1 in the flap position [the displacement from the C-atom mean plane is 0.3949 (6) Å], with the r.m.s. deviation was 0.2468 and with puckering parameters (Cremer and Pople, 1975) of Q (total puckering amplitude) = 0.6064 (10) Å, θ (azimuthal angle) = 127.68 (10)°, φ (phase angle) = 188.04 (15)°. The dihedral angle between ring A and ring B was 36.45 (7) °, and the dihedral angle between ring B and ring C was 10.34 (7) °. The spatial orientation of the phenyl ring can be described by the dihedral angle between the phenyl ring and the ring A [42.06 (6)]. The torsion angle of C4—N1—C3—S1 was -39.63 (13)°, and the torsion angle of N2—C2—C3—N1 was 120.16 (10)°. In the crystal, molecules are linked by N—H···O [N2—H1···O4=173.5 (14)°, N2···O4=3.0506 (14) Å] hydrogen bonds.

Experimental

The title compound was synthesized according to the literature method (Yu et al. (2009). Colorless Prism-shaped single crystals suitable for X-ray structure determination were recrystallized from acetone by the slow evaporation of the solvent at room temperature after several days.