(1′S,12′R,13′S,17′S)-15′,15′-Dimethyl-1,2-dihydro-11′,14′,16′,18′-tetra­oxa-7′-aza­spiro­[indole-3,8′-penta­cyclo­[10.6.0.02,9.03,7.013,17]octa­deca­ne]-2,10′-dione

V Sabari; R Ponnusamy; R Prasanna; R Raghunathan; S Aravindhan

doi:10.1107/S1600536813005436

. 2013 Mar 2;69(Pt 4):o466. doi: 10.1107/S1600536813005436

(1′S,12′R,13′S,17′S)-15′,15′-Dimethyl-1,2-dihydro-11′,14′,16′,18′-tetraoxa-7′-azaspiro[indole-3,8′-pentacyclo[10.6.0.0^2,9.0^3,7.0^13,17]octadecane]-2,10′-dione

V Sabari ^a, R Ponnusamy ^b, R Prasanna ^c, R Raghunathan ^c, S Aravindhan ^a,^*

PMCID: PMC3629507 PMID: 23634025

Abstract

In the title compound, C₂₂H₂₄N₂O₆, the indole ring has a twist conformation and the tetrahydro-2H-pyran-2-one ring a half-chair conformation. One of the pyrrolidine rings adopts an envelope conformation on the N atom, while the other has a twist conformation; the ‘butterfly’ angle between their mean planes is 62.98 (11)°. The dioxolane ring adopts a twist conformation and the tetrahydrofuran ring has an envelope conformation on the C atom in the fused tetrahydro-2H-pyran-2-one ring adjacent to the O atom of the tetrahydrofuran ring. The ‘butterfly’ angle between the mean planes of these two five-membered rings is 69.14 (10)°. In the crystal, molecules are linked by N—H⋯O hydrogen bonds, forming chains along the a axis.

Related literature

For the biological activity of indole derivatives, see: Stevenson et al. (2000 ▶); Rajeswaran et al. (1999 ▶); Amal Raj et al. (2003 ▶). For a related structure, see: Jagadeesan et al. (2012 ▶). graphic file with name e-69-0o466-scheme1.jpg

Experimental

Crystal data

C₂₂H₂₄N₂O₆
M _r = 412.43
Orthorhombic,
a = 9.2737 (5) Å
b = 11.6543 (8) Å
c = 18.8489 (14) Å
V = 2037.2 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 293 K
0.30 × 0.30 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker 2008 ▶) T _min = 0.922, T _max = 0.947
21465 measured reflections
4717 independent reflections
3800 reflections with I > 2σ(I)
R _int = 0.036

Refinement

R[F ² > 2σ(F ²)] = 0.037
wR(F ²) = 0.090
S = 1.04
4717 reflections
324 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.16 e Å⁻³

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Click here for additional data file.^{(21KB, cif)}

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536813005436/su2563sup1.cif

e-69-0o466-sup1.cif^{(21KB, cif)}

Click here for additional data file.^{(226.4KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813005436/su2563Isup2.hkl

e-69-0o466-Isup2.hkl^{(226.4KB, hkl)}

Click here for additional data file.^{(8.7KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813005436/su2563Isup3.cml

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	2.06	2.8849 (19)	161

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Symmetry code: (i) Inline graphic .

Acknowledgments

SA and VS thank the UGC, India, for financial support. The authors thank Dr Babu Varghese, Senior Scientific Officer, SAIF, IIT, Chennai, India, for the X-ray intensity data collection.

supplementary crystallographic information

Comment

Indole compounds can be used as bioactive drugs (Stevenson et al., 2000) and have also been proven to display high aldose reductase inhibitory activity (Rajeswaran et al., 1999), and antimicrobial and antifungal activities (Amal Raj et al., 2003).

The molecular structure of the title compound is shown in Fig. 1. The indole ring is essentially planar with the maximum deviation from planarity being 0.123 (2) Å for atom C7. Atom O1 deviates from the mean plane of the indole ring by 0.2095 (13) Å. The tetrahydro-2H-pyran-2-one ring (O3/C13-C17) has a half-chair conformation.

The five-membered pyrrolidine ring (N2/C9-C12) adopts an envelope conformation with atom N2 as the flap; it is 0.5267 (12) Å out of the mean plane formed by the other ring atoms. The other pyrrolidine ring (N2/C6/C12-C14) has a twist conformation on bond N2-C12; the "butter-fly" angle between their mean planes is 62.98 (11)°.

The dioxolane ring (O5/O6/C18-C20) adopts a twist conformation on bond O6-C20. The tetrahydrofuran ring (O4/C16-C19) adopts an envelope conformation with atom C17 deviating from the mean plane of the remaining ring atoms by 0.6286 (17) Å; the "butter-fly" angle between the ring mean planes is 69.14 (10) °.

In the crystal, molecules are linked via N-H···O hydrogen bonds forming chains propagating along the a axis direction (Table 1 and Fig. 2).

The title compound exhibits structural similarities with a related structure (Jagadeesan et al., 2012).

Experimental

A solution of 5,6-Dideoxy-l,2-O-isopropylidene-a-D-xylo-hept-5-enofuranurono-7,3-lactone (300 mg, 1.5 mmol), sarcosine (125 mg, 1.5 mmol) and isatin (210 mg, 1.5 mmol) were refluxed in dry toluene under a N₂ atmosphere for 6–8 h at 383 K using a Dean-Stark apparatus. After the completion of the reaction as indicated by TLC, toluene was evaporated under reduced pressure. The crude product was washed with water and extracted with dichloromethane (4 × 20mL). The combined organic layers were dried (MgSO₄) and filtered, concentrated in vacuum. The crude product was purified by column chromatography using hexane:EtOAc (7:3) mixture as eluent. On slow evaporation of the solvents colourless block-like crystals were obtained.