N-[(2S)-4-Chloro-2-(l-menth­yloxy)-5-oxo-2,5-dihydro­furan-3-yl]-l-valine

Xiu-Mei Song; Zhao-Yang Li; Zhao-Yang Wang; Jian-Xiao Li

doi:10.1107/S1600536809022120

. 2009 Jun 17;65(Pt 7):o1585. doi: 10.1107/S1600536809022120

N-[(2S)-4-Chloro-2-(l-menthyloxy)-5-oxo-2,5-dihydrofuran-3-yl]-l-valine

Xiu-Mei Song ^a, Zhao-Yang Li ^a, Zhao-Yang Wang ^a,^*, Jian-Xiao Li ^a

PMCID: PMC2969247 PMID: 21582860

Abstract

The title compound, C₁₉H₃₀ClNO₅, was obtained by the tandem asymmetric Michael addition–elimination reaction of (5S)-3,4-dichloro-5-(l-menthyloxy)furan-2(5H)-one and l-valine in the presence of potassium hydroxide. The furanone unit is approximately planar (r.m.s. deviation = 0.0204 Å) and the six-membered cyclohexane ring adopts a chair conformation. The crystal structure is stabilized by a network of O—H⋯O and N—H⋯O hydrogen bonds.

Related literature

For biologically active 4-amino-2(5H)-furanones, see: Kimura et al. (2000 ▶); Tanoury et al., 2008 ▶). For the synthesis of the precursor, (5S)-3,4-dichloro-5-(l-menthyloxy)furan-2(5H)-one, see: Chen & Geng (1993 ▶).

Experimental

Crystal data

C₁₉H₃₀ClNO₅
M _r = 387.89
Tetragonal,
a = 10.4540 (4) Å
c = 39.300 (3) Å
V = 4294.9 (4) Å³
Z = 8
Mo Kα radiation
μ = 0.20 mm⁻¹
T = 293 K
0.30 × 0.23 × 0.15 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.769, T _max = 0.867 (expected range = 0.860–0.970)
22031 measured reflections
3796 independent reflections
2868 reflections with I > 2σ(I)
R _int = 0.053

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.091
S = 1.04
3796 reflections
242 parameters
H-atom parameters constrained
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.23 e Å⁻³
Absolute structure: Flack, (1983 ▶), 1499 Friedel pairs
Flack parameter: −0.03 (8)

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: APEX2 and SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809022120/gk2204sup1.cif

e-65-o1585-sup1.cif^{(22.5KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809022120/gk2204Isup2.hkl

e-65-o1585-Isup2.hkl^{(186.2KB, 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
N1—H1⋯O2ⁱ	0.86	2.25	3.019 (3)	148
O1—H1A⋯O3ⁱⁱ	0.82	1.83	2.617 (2)	160

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The work was supported by the National Natural Science Foundation of China (grant No. 20772035) and the Natural Science Foundation of Guangdong Province, China (grant No. 5300082).

supplementary crystallographic information

Comment

Many 4-amino-2(5H)-furanones have been patented as prodrugs or insecticides and herbicides (Kimura et al., 2000; Tanoury et al., 2008). Attracted by versatility of 4-amino-2(5H)-furanones, we synthesized the title molecule with chiral synthon 3,4-dichloro-5-(S)-(l-menthyloxy)-2(5H)-furanone and L-valine in the presence of potassium hydroxide via the tandem asymmetric Michael addition-elimination reaction. With 2(5H)-furanone moiety and polyfunctional groups (carboxyl, amino, halogeno), the title compound is expected to be a biologically active product and an excellent ligand.

The structure of the title compound is illustrated in Fig. 1. The five-membered furane ring and the six-membered cyclohexane ring are connected via C10—O2—C11 ether bond. The configuration of chiral centers is following: C4(S), C10(S), C11(R), C12(S), C17(R)). The furanone unit is approximately planar, whereas the cyclohexane ring shows a chair conformation with three substituents occupying equatorial positions. The molecules are linked by O4—H6···O3 and N1—H1···O5 hydrogen bonds forming a three-dimensional network (Table. 1 and Fig. 2).

Experimental

The precursor, 3,4-dichloro-5-(S)-(L-menthyloxy)-2(5H)-furanone, was prepared according to the literature procedure (Chen et al., 1993).

After the mixture of L-valine (4.5 mmol) and potassium hydroxide (5.8 mmol) was dissolved in absolute ethyl alcohol under nitrogen atmosphere, dichloromethane solution of 3,4-dichloro-5-(S)-(l-menthyloxy)-2(5H)-furanone (3.0 mmol) was added. The reaction was carried out under the stirring at room temperature for 24 h. Once the reaction was complete, the solvents were removed under reduced pressure. The residual solid was dissolved in dichloromethane, and pH of the solution was adjusted to 3–4 with 15% of aqueous HCl solution. Then the combined organic layers from extraction were concentrated under reduced pressure, and the crude product was purified by silica gel column chromatography with the gradient mixture of petroleum ether and ethyl acetate to give the product yielding (I) 0.6891 g (59.2%). Data for (I): [α]^20°_D = 47.616° (c 0.481, CH₃CH₂OH); ¹H NMR (400 MHz, CDCl₃, TMS): 0.832 (3H, d, J = 6.0 Hz, CH₃), 0.904–0.935 (7H, m, CH, 2CH₃), 0.955–1.057 (8H, m, 2CH₃, CH₂), 1.312–1.457 (2H, m, 2CH), 1.605–1.710 (2H, m, CH₂), 2.100–2.350 (3H, m, CH₂, CH), 3.505–3.609 (1H, m, CH), 4.726 (1H, s, NH), 5.116–5.138 (1H, d, J = 8.8 Hz, CH), 5.700 (1H, s, CH), 10.212 (1H, s, COOH); ESI-MS, m/z (%): Calcd for C₁₉H₃₁ClNO₅⁺([M+H]⁺): 388.19, Found: 388.15 (100.0)