research communications\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890
Volume 77| Part 2| February 2021| Pages 86-90
https://doi.org/10.1107/S2056989020016801

Crystal structure and Hirshfeld surface analysis of ethyl (4R,4aS)-2-methyl-5,8-dioxo-6-phenyl-4a,5,6,7,7a,8-hexa­hydro-4H-furo[2,3-f]iso­indole-4-carboxyl­ate

CROSSMARK_Color_square_no_text.svg
Vladimir P. Zaytsev,a Lala V. Chervyakova,a Elena A. Sorokina,a Kirill A. Vasilyev,a Sevim Türktekin Çelikesir,b Mehmet Akkurtb and Ajaya Bhattaraic*

aDepartment of Organic Chemistry, Peoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya St., 117198 Moscow, Russian Federation, bDepartment of Physics, Faculty of Sciences, Erciyes University, 38039 Kayseri, Turkey, and cDepartment of Chemistry, M.M.A.M.C (Tribhuvan University), Biratnagar, Nepal
*Correspondence e-mail: bkajaya@yahoo.com

Edited by M. Weil, Vienna University of Technology, Austria (Received 24 November 2020; accepted 30 December 2020; online 8 January 2021)

In the title compound, C20H19NO5, the central six-membered ring has a slightly distorted half-chair conformation, with puckering parameters of QT = 0.3387 (11) Å, θ = 49.11 (19)° and φ = 167.3 (2)°. The conformation of the fused pyrrolidine ring is that of an envelope. Mol­ecules are connected by inter­molecular C—H⋯O hydrogen bonds, C—H⋯π inter­actions and π–π stacking inter­actions [centroid-to-centroid distance = 3.9536 (11) Å, with a slippage of 2.047 Å], forming a three-dimensional network. The most important contributions to the surface contacts are from H⋯H (46.3%), O⋯H/H⋯O (31.5%) and C⋯H/H⋯C (17.3%) inter­actions, as concluded from a Hirshfeld surface analysis.

CCDC reference: 2053210

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1. Chemical context

This work is a continuation of Diels–Alder reaction studies on vinyl­arene systems, previously carried out for the tandem acyl­ation/[4 + 2] cyclo­addition between 3-(ar­yl)allyl­amines and maleic anhydrides or acryloyl chlorides as an example of an IMDAV (the acronym for Intra Mol­ecular Diels–Alder Vinyl­arene) reaction. An IMDAV reaction is a useful tool for the one-step synthesis of benzo­furans, indoles and benzo­thio­phenes annulated with other carbo- and heterocycles (Krishna et al., 2020[Krishna, G., Grudinin, D. G., Nikitina, E. V. & Zubkov, F. I. (2020). Synthesis (submitted).]). Previously, our group carried out a domino-sequence reaction involving acyl­ation/IMDAV/aromatization steps, which led to the target furo- and thieno[2,3-f]iso­indoles (Zubkov et al., 2016[Zubkov, F. I., Zaytsev, V. P., Mertsalov, D. F., Nikitina, E. V., Horak, Y. I., Lytvyn, R. Z., Homza, Y. V., Obushak, M. D., Dorovatovskii, P. V., Khrustalev, V. N. & Varlamov, A. V. (2016). Tetrahedron, 72, 2239-2253.]; Horak et al., 2015[Horak, Y. I., Lytvyn, R. Z., Homza, Y. V., Zaytsev, V. P., Mertsalov, D. F., Babkina, M. N., Nikitina, E. V., Lis, T., Kinzhybalo, V., Matiychuk, V. S., Zubkov, F. I., Varlamov, A. V. & Obushak, M. D. (2015). Tetrahedron Lett. 56, 4499-4501.], 2017[Horak, Y. I., Lytvyn, R. Z., Laba, Y.-O. V., Homza, Y. V., Zaytsev, V. P., Nadirova, M. A., Nikanorova, T. V., Zubkov, F. I., Varlamov, A. V. & Obushak, M. D. (2017). Tetrahedron Lett. 58, 4103-4106.]; Nadirova et al., 2020[Nadirova, M. A., Laba, Y.-O. V., Zaytsev, V. P., Sokolova, J. S., Pokazeev, K. M., Anokhina, V. A., Khrustalev, V. N., Horak, Y. I., Lytvyn, R. Z., Siczek, M., Kinzhybalo, V., Zubavichus, Y. V., Kuznetsov, M. L., Obushak, M. D. & Zubkov, F. I. (2020). Synthesis, 52, 2196-2223.]).

[Scheme 1]

The present communication is devoted to another IMDAV reaction involving an oxidation step. We report here the first case of a three-component IMDAV/oxidation reaction between 3-(fur­yl)allyl­amine (1), ethyl­fumaroyl chloride (2) and oxygen. Unlike many other reactions, this process does not stop at the furo[2,3-f]iso­indole (4) formation but is continued by an oxidation step yielding the 8-oxofuro[2,3-f]iso­indole (5) (Fig. 1[link]). The intra­molecular [4 + 2] cyclo­addition/oxidation sequence occurs under reflux conditions of the reaction mixture in benzene as a solvent and in ambient atmosphere; after standard purification procedures the title compound (5) was isolated in low yield.

[Figure 1]
Figure 1
Synthesis scheme of ethyl 2-methyl-5,8-dioxo-6-phenyl-4a,5,6,7,7a,8-hexa­hydro-4H-furo[2,3-f]iso­indole-4-carboxyl­ate (5).

Weak inter­molecular inter­actions, e.g. hydrogen, halogen, chalcogen, pnictogen, tetrel and triel bonding, as well as agostic, anagostic, π–π stacking, n–π*, π-cation and π-anion inter­actions, play an important role in synthesis, catalysis, crystal engineering, or mol­ecular recognition (Afkhami et al., 2017[Afkhami, F. A., Khandar, A. A., Mahmoudi, G., Maniukiewicz, W., Gurbanov, A. V., Zubkov, F. I., Şahin, O., Yesilel, O. Z. & Frontera, A. (2017). CrystEngComm, 19, 1389-1399.]; Asadov et al., 2016[Asadov, Z. H., Rahimov, R. A., Ahmadova, G. A., Mammadova, K. A. & Gurbanov, A. V. (2016). J. Surfact. Deterg. 19, 145-153.]; Gurbanov et al., 2017[Gurbanov, A. V., Mahmudov, K. T., Sutradhar, M., Guedes da Silva, M. F. C., Mahmudov, T. A., Guseinov, F. I., Zubkov, F. I., Maharramov, A. M. & Pombeiro, A. J. L. (2017). J. Organomet. Chem. 834, 22-27.], 2018[Gurbanov, A. V., Mahmoudi, G., Guedes da Silva, M. F. C., Zubkov, F. I., Mahmudov, K. T. & Pombeiro, A. J. L. (2018). Inorg. Chim. Acta, 471, 130-136.]; Karmakar et al., 2017[Karmakar, A., Rúbio, G. M. D. M., Paul, A., Guedes da Silva, M. F. C., Mahmudov, K. T., Guseinov, F. I., Carabineiro, S. A. C. & Pombeiro, A. J. L. (2017). Dalton Trans. 46, 8649-8657.]; Kopylovich et al., 2011a[Kopylovich, M. N., Mahmudov, K. T., Haukka, M., Luzyanin, K. V. & Pombeiro, A. J. L. (2011a). Inorg. Chim. Acta, 374, 175-180.],b[Kopylovich, M. N., Mahmudov, K. T., Mizar, A. & Pombeiro, A. J. L. (2011b). Chem. Commun. 47, 7248-7250.]; Ma et al., 2017a[Ma, Z., Gurbanov, A. V., Maharramov, A. M., Guseinov, F. I., Kopylovich, M. N., Zubkov, F. I., Mahmudov, K. T. & Pombeiro, A. J. L. (2017a). J. Mol. Catal. A Chem. 426, 526-533.],b[Ma, Z., Gurbanov, A. V., Sutradhar, M., Kopylovich, M. N., Mahmudov, K. T., Maharramov, A. M., Guseinov, F. I., Zubkov, F. I. & Pombeiro, A. J. L. (2017b). Mol. Catal. 428, 17-23.]; Maharramov et al., 2018[Maharramov, A. M., Shikhaliyev, N. Q., Suleymanova, G. T., Gurbanov, A. V., Babayeva, G. V., Mammadova, G. Z., Zubkov, F. I., Nenajdenko, V. G., Mahmudov, K. T. & Pombeiro, A. J. L. (2018). Dyes Pigm. 159, 135-141.]; Mahmoudi et al., 2017[Mahmoudi, G., Dey, L., Chowdhury, H., Bauza, A., Ghosh, B. K., Kirillov, A. M., Seth, S. K., Gurbanov, A. V. & Frontera, A. (2017). Inorg. Chim. Acta, 461, 192-205.], 2019[Mahmoudi, G., Khandar, A. A., Afkhami, F. A., Mirslaw, B., Gurbanov, A. V., Zubkov, F. I., Kennedy, A., Franconetti, A. & Frontera, A. (2019). CrystEngComm, 21, 108-117.]; Mahmudov et al., 2010[Mahmudov, K. T., Maharramov, A. M., Aliyeva, R. A., Aliyev, I. A., Kopylovich, M. N. & Pombeiro, A. J. L. (2010). Anal. Lett. 43, 2923-2938.], 2020[Mahmudov, K. T., Gurbanov, A. V., Aliyeva, V. A., Resnati, G. & Pombeiro, A. J. L. (2020). Coord. Chem. Rev. 418, 213381.]; Mizar et al., 2012[Mizar, A., Guedes da Silva, M. F. C., Kopylovich, M. N., Mukherjee, S., Mahmudov, K. T. & Pombeiro, A. J. L. (2012). Eur. J. Inorg. Chem. pp. 2305-2313.]; Sutradhar et al., 2015[Sutradhar, M., Martins, L. M. D. R. S., Guedes da Silva, M. F. C., Mahmudov, K. T., Liu, C.-M. & Pombeiro, A. J. L. (2015). Eur. J. Inorg. Chem. pp. 3959-3969.]). Herein, we highlight the role of weak inter­actions in the structural features of 5.

2. Structural commentary

In the mol­ecule of the title compound 5 (Fig. 2[link]), the central six-membered ring (C1/C4–C6/C9–C10) has a slightly distorted half-chair conformation, with puckering parameters (Cremer & Pople, 1975[Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.]) of QT = 0.3387 (11) Å, θ = 49.11 (19)° and φ = 167.3 (2)°. The fused pyrrolidine ring (N1/C6–C9) adopts an envelope conformation with the C9 atom as the flap [the puckering parameters are Q(2) = 0.3634 (11) Å and φ(2) = 289.63 (17)°], while the fused furan ring (O1/C1–C4) is essentially planar [r.m.s. deviation = 0.001 Å]. All bond lengths and angles in the title compound (5) are comparable to the closely related compound (3aR,4R,4aS,9aR)-4-hy­droxy­perhydro­furo(2,3-f)indolizin-7(2H)-one (CSD refcode SIBJET; Švorc et al., 2007[Švorc, Ľ., Vrábel, V., Kožíšek, J., Marchalín, Š. & Žúžiová, J. (2007). Acta Cryst. E63, o1452-o1454.]).

[Figure 2]
Figure 2
The mol­ecular structure of 5 with displacement ellipsoids for the non-hydrogen atoms drawn at the 50% probability level.

3. Supra­molecular features

In the crystal structure of 5, mol­ecules are linked by two kinds of C—H⋯π inter­actions (Table 1[link]). The first one is between an aromatic H atom (H14) of the phenyl group (C11–C16) and the centroid of the O1/C1–C4 furan ring (Cg1) of an adjacent mol­ecule, and the second one is between the methine H atom (H6) of the fused pyrrolidine ring (N1/C6–C9) and the centroid of the C11–C16 phenyl ring (Cg4) of another adjacent mol­ecule (Fig. 3[link]).

Table 1
Hydrogen-bond geometry (Å, °)

Cg1 and Cg4 are the centroids of the furan (O1/C1–C4) and phenyl (C11–C16) rings, respectively.
D—H⋯A D—H H⋯A D⋯A D—H⋯A
C14—H14⋯O1i 0.95 2.53 3.4766 (16) 172
C17—H17A⋯O4ii 0.98 2.51 3.4913 (18) 176
C17—H17B⋯O2iii 0.98 2.31 3.2441 (15) 159
C17—H17C⋯O1iv 0.98 2.57 3.4232 (14) 145
C19—H19B⋯O1v 0.99 2.54 3.5181 (17) 168
C6—H6⋯Cg4vi 1.00 2.71 3.5892 (14) 146
C14—H14⋯Cg1i 0.95 2.93 3.8320 (16) 159
Symmetry codes: (i) [-x+2, -y+1, -z+1]; (ii) x+1, y, z; (iii) [-x+1, -y+1, -z+2]; (iv) [-x+1, -y+2, -z+2]; (v) [x-1, y, z]; (vi) [-x+1, -y+1, -z+1].
[Figure 3]
Figure 3
A view of the C—H⋯π inter­actions and π–π stacking inter­actions in the crystal structure of 5. [Symmetry codes: (a) 1 − x, 1 − y, 1 − z; (b) 2 − x, 1 − y, 1 − z.]

In addition, there is a π–π stacking inter­action [Cg4⋯Cg4i = 3.9536 (11) Å; symmetry code: (i) 2 − x, 1 − y, 1 − z], with a rather large slippage of 2.047 Å (Fig. 3[link]).

The final three-dimensional network structure is completed by C—H⋯O hydrogen bonding (Fig. 4[link]) between a phenyl H atom and the furan O atom (C14—H14⋯O1i), between a methyl H atom and the carbonyl O atom (C17—H17A⋯O4ii and C17—H17B⋯O2iii), and between a methyl H atom and a methyl­ene H atom and the furan O atom (C17—H17C⋯O1iv and C19—H19B⋯O1v). Numerical details of the hydrogen-bonding inter­actions as well as symmetry codes are given in Table 1[link].

[Figure 4]
Figure 4
A view of the inter­molecular C—H⋯O inter­actions in the crystal structure of 5.

4. Hirshfeld surface analysis

Hirshfeld surfaces and their associated two-dimensional fingerprint plots (McKinnon et al., 2007[McKinnon, J. J., Jayatilaka, D. & Spackman, M. A. (2007). Chem. Commun. pp. 3814-3816.]) were used to qu­antify the various inter­molecular inter­actions, and were generated using CrystalExplorer17 (Turner et al., 2017[Turner, M. J., McKinnon, J. J., Wolff, S. K., Grimwood, D. J., Spackman, P. R., Jayatilaka, D. & Spackman, M. A. (2017). CrystalExplorer17. The University of Western Australia.]). The shorter and longer contacts are indicated as red and blue spots on the Hirshfeld surfaces, and contacts with distances equal to the sum of the van der Waals radii are represented as white spots. Hirshfeld surfaces of the title compound 5 mapped over the normalized distance, dnorm, using a standard surface resolution with a fixed colour scale of −0.2980 (red) to 1.4527 a.u. (blue) are illustrated in Fig. 5[link]a. The shape-index of the Hirshfeld surface is a tool for visualizing the π–π stacking by the presence of adjacent red and blue triangles. The plot of the Hirshfeld surface mapped over shape-index shown in Fig. 5[link]b clearly suggests that π–π inter­actions in (5) are significant.

[Figure 5]
Figure 5
(a) A view of the three-dimensional Hirshfeld surface for 5, plotted over dnorm in the range −0.2980 to 1.4527 a.u.; (b) Hirshfeld surface of the title compound 5 plotted over shape-index.

Various inter­molecular contacts are collated in Table 2[link]. Associated two-dimensional fingerprint plots together with their percentage contributions are shown in Fig. 6[link]. The crystal packing is dominated by H⋯H contacts, representing van der Waals inter­actions (46.3% contribution to the overall surface), followed by O⋯H/H⋯O and C⋯H/H⋯C inter­actions, which contribute 31.5% and 17.3%, respectively. All other contacts have a minor contribution to the crystal packing.

Table 2
Summary of short inter­atomic contacts (Å) in the title compound 5

Contact Distance Symmetry operation
H17A⋯O4 2.51 1 + x, y, z;
H14⋯O1 2.53 2 − x, 1 − y, 1 − z;
H17C⋯O1 2.57 1 − x, 2 − y, 2 − z;
H17B⋯O2 2.31 1 − x, 1 − y, 2 − z;
H8A⋯O3 2.69 1 − x, 2 − y, 1 − z;
O4⋯H13 2.67 −1 + x, y, 1 + z;
H20C⋯C3 3.09 −x, 2 − y, 2 − z;
H6⋯C16 2.72 1 − x, 1 − y, 1 − z;
H17B⋯H12 2.47 x, y, 1 + z;
H20C⋯H16 2.56 −1 + x, 1 + y, z.
[Figure 6]
Figure 6
A view of the two-dimensional fingerprint plots for 5, showing (a) all inter­actions, and delineated into (b) H⋯H, (c) O⋯H/H⋯O and (d) C⋯H/H⋯C inter­actions. The di and de values are the closest inter­nal and external distances (in Å) from given points on the Hirshfeld surface contacts.

5. Database survey

A search of the Cambridge Crystallographic Database (CSD version 5.40, update of September 2019; Groom et al., 2016[Groom, C. R., Bruno, I. J., Lightfoot, M. P. & Ward, S. C. (2016). Acta Cryst. B72, 171-179.]) yielded five entries closely related to 5, viz. 2,4,6-triphenyl-7a,8-di­hydro-4H-furo[2,3-f]iso­indole-5,7(4aH,6H)-dione (CSD refcode JOGYIP; Zhou et al., 2014[Zhou, L., Zhang, M., Li, W. & Zhang, J. (2014). Angew. Chem. Int. Ed. 53, 6542-6545.]), (4R*,4aR*,7aS*)-5-oxo-6-phenyl-4a,5,6,7,7a,8-hexa­hydro-4H-furo[2,3-f]iso­indole-4-carb­oxy­lic acid (LESXIS; Horak et al., 2013[Horak, Y. I., Lytvyn, R. Z., Zubkov, F. I., Nikitina, E. V., Homza, Y. V., Lis, T., Kinzhybalo, V. & Obushak, M. D. (2013). Acta Cryst. E69, o273-o274.]), 6-benzyl-2,4,4a-trimethyl-5-oxo-4a,5,6,7,7a,8-hexa­hydro-4H-furo[2,3-f]iso­indole-4-carb­oxy­lic acid (QAFSUO; Zubkov et al., 2016[Zubkov, F. I., Zaytsev, V. P., Mertsalov, D. F., Nikitina, E. V., Horak, Y. I., Lytvyn, R. Z., Homza, Y. V., Obushak, M. D., Dorovatovskii, P. V., Khrustalev, V. N. & Varlamov, A. V. (2016). Tetrahedron, 72, 2239-2253.]), 6-benzyl-4-methyl-5-oxo-4a,5,6,7,7a,8-hexa­hydro-4H-furo[2,3-f]iso­indole-4-carb­oxy­lic acid (QAFTAV; Zubkov et al., 2016[Zubkov, F. I., Zaytsev, V. P., Mertsalov, D. F., Nikitina, E. V., Horak, Y. I., Lytvyn, R. Z., Homza, Y. V., Obushak, M. D., Dorovatovskii, P. V., Khrustalev, V. N. & Varlamov, A. V. (2016). Tetrahedron, 72, 2239-2253.]) and 6-allyl-5-oxo-4a,5,6,7,7a,8-hexa­hydro-4H-furo[2,3-f]iso­indole-4-carb­oxy­lic acid (QUKPAP; Horak et al., 2015[Horak, Y. I., Lytvyn, R. Z., Homza, Y. V., Zaytsev, V. P., Mertsalov, D. F., Babkina, M. N., Nikitina, E. V., Lis, T., Kinzhybalo, V., Matiychuk, V. S., Zubkov, F. I., Varlamov, A. V. & Obushak, M. D. (2015). Tetrahedron Lett. 56, 4499-4501.]).

In the crystal structure of JOGYIP (space group P[\overline{1}]), the packing is stabilized by C—H⋯O inter­molecular contacts, C—H⋯π inter­actions and π–π stacking inter­actions, forming a three-dimensional network.

In the crystal structure of LESXIS (Pbca), the asymmetric unit contains two mol­ecules with similar bond lengths and angles. In both mol­ecules, the conformation of the cyclo­hexene ring is that of a half-chair, while the pyrrolidinone ring adopts an envelope conformation with the γ-carbon atom of the α-pyrrolidinone ring as the flap. In the crystal, O—H⋯O hydrogen bonds between the carb­oxy­lic and carbonyl groups link alternate independent mol­ecules into chains propagating parallel to the b-axis direction. The crystal packing also features weak C—H⋯π inter­actions.

In the crystal structures of QAFSUO (P21/c) and QAFTAV (P21/n), the three-dimensional packings are stabilized by O—H⋯O inter­molecular bonds, C—H⋯O inter­molecular contacts and C—H⋯π inter­actions.

The asymmetric unit of QUKPAP (P21/c) comprises two similar mol­ecules, A and B, of the same chirality. The only considerable difference concerns the conformation of the allyl group. The five-membered iso­indole rings adopt envelope conformations, whereas the six-membered rings are half-chair-puckered. The carboxyl hydrogen atoms are involved in strong hydrogen-bond formation with the carbonyl atoms of neighboring mol­ecules, giving rise to (A⋯B⋯)n chains.

In the five structures, the different groups bonded to the central twelve-membered ring systems account for the distinct inter­molecular inter­actions in the crystals.

6. Synthesis and crystallization

Ethyl 2-methyl-5,8-dioxo-6-phenyl-4a,5,6,7,7a,8-hexa­hydro-4H-furo[2,3-f]iso­indole-4-carboxyl­ate (5) was synthesized according to a previously reported method (Zubkov et al., 2016[Zubkov, F. I., Zaytsev, V. P., Mertsalov, D. F., Nikitina, E. V., Horak, Y. I., Lytvyn, R. Z., Homza, Y. V., Obushak, M. D., Dorovatovskii, P. V., Khrustalev, V. N. & Varlamov, A. V. (2016). Tetrahedron, 72, 2239-2253.]; Nadirova et al., 2020[Nadirova, M. A., Laba, Y.-O. V., Zaytsev, V. P., Sokolova, J. S., Pokazeev, K. M., Anokhina, V. A., Khrustalev, V. N., Horak, Y. I., Lytvyn, R. Z., Siczek, M., Kinzhybalo, V., Zubavichus, Y. V., Kuznetsov, M. L., Obushak, M. D. & Zubkov, F. I. (2020). Synthesis, 52, 2196-2223.]): A solution of ethyl fumaroyl chloride (2; 3.6 g, 22.5 mmol) in benzene (25 ml) was added dropwise to a mixture of N-[(2E)-3-(5-methyl­furan-2-yl)prop-2-en-1-yl]aniline (1; 3.2 g, 15.0 mmol) with tri­ethyl­amine (4.2 ml, 30 mmol) in benzene (25 ml). The mixture was heated under reflux for 6 h. The mixture was then cooled to r.t. and poured into water (200 ml). The organic layer was separated, the aqueous layer was extracted with AcOEt (3 × 50 ml). The organic layers were combined and dried over anhydrous MgSO4. The extract was evaporated under reduced pressure, and the residue was crystallized at 279 K within a few days. The resulting light-beige crystals were filtered off and washed with diethyl ether (3 × 10 ml). Yield 1.4 g (26%). M.p. = 437–439 K. IR (KBr), ν (cm−1): 1736, 1704, 1665. 1H NMR (CDCl3, 600.2 MHz, 301 K): δ = 7.55 (dd, 2H, HAr, J = 7.6, J = 2.0), 7.34 (td, 2H, HAr, J = 7.6, J = 2.0), 7.14 (td, 1H, HAr, J = 7.6, J = 2.0), 6.32 (s, 1H, H3), 4.56 (s, 1H, H4), 4.43 (dd, 1H, H-7a, J = 8.5, J = 2.0), 4.27–4.17 (m, 2H, OCH2), 4.05 (ddd, 1H, H-7B, J = 2.0, J = 6.5), 3.76 (dd, 1H, H-4a, J = 1.7, J = 8.5), 3.51 (td, 1H, H-7A, J = 2.0, J = 6.5), 2.39 (d, 3H, CH3, J = 1.5), 1.30 (td, 3H, CH2CH3, J = 2.2, J = 7.2). 13C NMR (CDCl3, 150.9 MHz, 301 K): δ = 181.4, 170.9, 170.5 (CO, CO2, NCO), 160.9, 145.3, 138.7, 136.9, 128.8 (2C), 124.9, 119.8 (2C), 109.8, 62.0, 49.4, 45.4, 41.8, 38.7, 14.1 (CH3), 14.0 (CH3). MS (APCI): m/z = 354 [M + H]+.

7. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 3[link]. H atoms bound to C atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms, with C—H = 0.95–1.00 Å and Uiso(H) = 1.2 or 1.5Ueq(C).

Table 3
Experimental details

Crystal data
Chemical formula C20H19NO5
Mr 353.36
Crystal system, space group Triclinic, P[\overline{1}]
Temperature (K) 120
a, b, c (Å) 8.8100 (18), 9.9182 (16), 11.165 (2)
α, β, γ (°) 81.205 (7), 70.657 (6), 72.642 (4)
V (Å3) 877.0 (3)
Z 2
Radiation type Mo Kα
μ (mm−1) 0.10
Crystal size (mm) 0.2 × 0.2 × 0.2
 
Data collection
Diffractometer Bruker APEXII CCD
Absorption correction Multi-scan (SADABS; Krause et al., 2015[Krause, L., Herbst-Irmer, R., Sheldrick, G. M. & Stalke, D. (2015). J. Appl. Cryst. 48, 3-10.])
Tmin, Tmax 0.659, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections 19857, 5332, 4669
Rint 0.019
(sin θ/λ)max (Å−1) 0.716
 
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.044, 0.125, 1.04
No. of reflections 5332
No. of parameters 237
H-atom treatment H-atom parameters constrained
Δρmax, Δρmin (e Å−3) 0.53, −0.18
Computer programs: APEX2 and SAINT (Bruker, 2014[Bruker (2014). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]), SHELXT (Sheldrick, 2015a[Sheldrick, G. M. (2015a). Acta Cryst. A71, 3-8.]), SHELXL (Sheldrick, 2015b[Sheldrick, G. M. (2015b). Acta Cryst. C71, 3-8.]), ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]) and PLATON (Spek, 2020[Spek, A. L. (2020). Acta Cryst. E76, 1-11.]).

Supporting information

CCDC reference: 2053210

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989020016801/wm5592sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989020016801/wm5592Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2056989020016801/wm5592Isup3.cml

checkCIF report


Computing details top

Data collection: APEX2 (Bruker, 2014); cell refinement: SAINT (Bruker, 2014); data reduction: SAINT (Bruker, 2014); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: PLATON (Spek, 2020).

Ethyl (4R,4aS)-2-methyl-5,8-dioxo-6-phenyl-4a,5,6,7,7a,8-hexahydro-4H-furo[2,3-f]isoindole-4-carboxylate top
Crystal data top
C20H19NO5Z = 2
Mr = 353.36F(000) = 372
Triclinic, P1Dx = 1.338 Mg m−3
a = 8.8100 (18) ÅMo Kα radiation, λ = 0.71073 Å
b = 9.9182 (16) ÅCell parameters from 9941 reflections
c = 11.165 (2) Åθ = 2.6–30.6°
α = 81.205 (7)°µ = 0.10 mm−1
β = 70.657 (6)°T = 120 K
γ = 72.642 (4)°Prism, light beige
V = 877.0 (3) Å30.2 × 0.2 × 0.2 mm
Data collection top
Bruker APEXII CCD
diffractometer		5332 independent reflections
Radiation source: sealed tube4669 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.019
ω and φ scansθmax = 30.6°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Krause et al., 2015)		h = −12→12
Tmin = 0.659, Tmax = 0.746k = −14→14
19857 measured reflectionsl = −15→15
Refinement top
Refinement on F20 restraints
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.044H-atom parameters constrained
wR(F2) = 0.125 w = 1/[σ2(Fo2) + (0.0747P)2 + 0.2272P]
where P = (Fo2 + 2Fc2)/3
S = 1.04(Δ/σ)max = 0.001
5332 reflectionsΔρmax = 0.53 e Å−3
237 parametersΔρmin = −0.18 e Å−3
Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.49262 (11)0.82060 (9)0.82393 (8)0.01800 (17)
C20.52219 (12)0.77526 (10)1.01557 (9)0.01914 (18)
C30.41740 (12)0.69939 (10)1.01089 (9)0.02056 (18)
H30.3674010.6392661.0771160.025*
C40.39835 (11)0.72876 (9)0.88651 (9)0.01857 (17)
C50.29588 (12)0.68264 (10)0.82451 (9)0.02036 (18)
H50.2975390.5816870.8527680.024*
C60.37337 (12)0.69298 (10)0.67917 (9)0.01928 (17)
H60.2891130.6868760.6397390.023*
C70.52879 (12)0.57073 (10)0.63456 (9)0.02000 (18)
C80.56409 (13)0.76769 (10)0.49121 (9)0.02031 (18)
H8A0.5089100.7741890.4255930.024*
H8B0.6506110.8202270.4588340.024*
C90.43715 (12)0.82351 (9)0.61653 (9)0.01886 (17)
H90.3438980.9026340.5995060.023*
C100.52459 (12)0.87442 (9)0.69242 (9)0.01830 (17)
C110.78337 (12)0.53580 (10)0.44672 (9)0.01931 (18)
C120.84407 (13)0.58679 (11)0.32111 (10)0.0241 (2)
H120.7868420.6764870.2921630.029*
C130.98773 (14)0.50692 (13)0.23836 (11)0.0308 (2)
H131.0282780.5419940.1530990.037*
C141.07198 (14)0.37572 (13)0.28046 (12)0.0321 (2)
H141.1693240.3203470.2238660.039*
C151.01305 (14)0.32603 (11)0.40575 (11)0.0283 (2)
H151.0715380.2367530.4344360.034*
C160.87003 (13)0.40465 (10)0.48986 (10)0.02336 (19)
H160.8314460.3699620.5755210.028*
C170.59178 (14)0.78967 (11)1.11582 (10)0.0247 (2)
H17A0.7116890.7806611.0788530.037*
H17B0.5736980.7152731.1834710.037*
H17C0.5358880.8825921.1513010.037*
C180.11631 (12)0.77419 (11)0.87182 (10)0.02347 (19)
C19−0.08020 (14)0.98413 (12)0.82766 (12)0.0312 (2)
H19A−0.0987231.0296900.9060940.037*
H19B−0.1669380.9334750.8434950.037*
C20−0.08800 (16)1.09358 (14)0.71871 (14)0.0416 (3)
H20A−0.0640351.0466280.6408740.062*
H20B−0.0052591.1460230.7068110.062*
H20C−0.1997681.1592910.7375940.062*
N10.63587 (10)0.61915 (8)0.52807 (8)0.01870 (16)
O10.56926 (8)0.85082 (7)0.90205 (6)0.01874 (14)
O20.55020 (10)0.45051 (8)0.68426 (8)0.02855 (17)
O30.61486 (10)0.95404 (8)0.64330 (7)0.02436 (16)
O40.01858 (11)0.75061 (11)0.97188 (8)0.0372 (2)
O50.08563 (9)0.88584 (8)0.79139 (8)0.02685 (17)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0213 (4)0.0180 (4)0.0169 (4)−0.0062 (3)−0.0084 (3)0.0004 (3)
C20.0218 (4)0.0193 (4)0.0156 (4)−0.0045 (3)−0.0065 (3)0.0010 (3)
C30.0240 (4)0.0211 (4)0.0172 (4)−0.0079 (3)−0.0070 (3)0.0024 (3)
C40.0204 (4)0.0182 (4)0.0183 (4)−0.0059 (3)−0.0071 (3)−0.0001 (3)
C50.0216 (4)0.0207 (4)0.0210 (4)−0.0082 (3)−0.0077 (3)0.0001 (3)
C60.0212 (4)0.0191 (4)0.0201 (4)−0.0062 (3)−0.0088 (3)−0.0009 (3)
C70.0228 (4)0.0182 (4)0.0220 (4)−0.0068 (3)−0.0095 (3)−0.0008 (3)
C80.0277 (4)0.0163 (4)0.0171 (4)−0.0030 (3)−0.0101 (3)0.0005 (3)
C90.0232 (4)0.0170 (4)0.0176 (4)−0.0040 (3)−0.0093 (3)0.0000 (3)
C100.0229 (4)0.0151 (4)0.0170 (4)−0.0041 (3)−0.0075 (3)0.0000 (3)
C110.0215 (4)0.0192 (4)0.0208 (4)−0.0050 (3)−0.0105 (3)−0.0031 (3)
C120.0258 (5)0.0264 (5)0.0212 (4)−0.0049 (4)−0.0105 (4)−0.0015 (3)
C130.0279 (5)0.0398 (6)0.0237 (5)−0.0050 (4)−0.0082 (4)−0.0059 (4)
C140.0254 (5)0.0362 (6)0.0333 (6)−0.0004 (4)−0.0091 (4)−0.0128 (5)
C150.0256 (5)0.0238 (5)0.0377 (6)−0.0007 (4)−0.0156 (4)−0.0073 (4)
C160.0258 (5)0.0203 (4)0.0273 (5)−0.0041 (3)−0.0140 (4)−0.0019 (3)
C170.0318 (5)0.0269 (5)0.0200 (4)−0.0102 (4)−0.0133 (4)0.0021 (3)
C180.0220 (4)0.0282 (5)0.0236 (4)−0.0104 (4)−0.0081 (3)−0.0012 (4)
C190.0214 (5)0.0308 (5)0.0354 (6)−0.0035 (4)−0.0043 (4)−0.0008 (4)
C200.0310 (6)0.0337 (6)0.0474 (7)−0.0021 (5)−0.0057 (5)0.0073 (5)
N10.0232 (4)0.0154 (3)0.0183 (3)−0.0037 (3)−0.0092 (3)0.0003 (3)
O10.0228 (3)0.0200 (3)0.0160 (3)−0.0080 (2)−0.0081 (2)0.0012 (2)
O20.0321 (4)0.0176 (3)0.0336 (4)−0.0080 (3)−0.0081 (3)0.0041 (3)
O30.0334 (4)0.0215 (3)0.0213 (3)−0.0130 (3)−0.0090 (3)0.0028 (3)
O40.0260 (4)0.0512 (5)0.0276 (4)−0.0097 (4)−0.0042 (3)0.0070 (4)
O50.0211 (3)0.0244 (4)0.0303 (4)−0.0051 (3)−0.0040 (3)0.0017 (3)
Geometric parameters (Å, º) top
C1—C41.3712 (12)C11—C121.3987 (14)
C1—O11.3775 (11)C11—C161.4023 (13)
C1—C101.4478 (12)C11—N11.4156 (12)
C2—C31.3712 (13)C12—C131.3906 (15)
C2—O11.3736 (11)C12—H120.9500
C2—C171.4849 (13)C13—C141.3904 (17)
C3—C41.4294 (13)C13—H130.9500
C3—H30.9500C14—C151.3893 (18)
C4—C51.5035 (13)C14—H140.9500
C5—C181.5305 (14)C15—C161.3897 (15)
C5—C61.5385 (14)C15—H150.9500
C5—H51.0000C16—H160.9500
C6—C71.5282 (14)C17—H17A0.9800
C6—C91.5420 (13)C17—H17B0.9800
C6—H61.0000C17—H17C0.9800
C7—O21.2239 (12)C18—O41.2031 (13)
C7—N11.3737 (12)C18—O51.3356 (13)
C8—N11.4734 (12)C19—O51.4587 (13)
C8—C91.5316 (13)C19—C201.5066 (18)
C8—H8A0.9900C19—H19A0.9900
C8—H8B0.9900C19—H19B0.9900
C9—C101.5369 (13)C20—H20A0.9800
C9—H91.0000C20—H20B0.9800
C10—O31.2289 (12)C20—H20C0.9800
C4—C1—O1110.30 (8)C12—C11—N1118.92 (8)
C4—C1—C10128.08 (8)C16—C11—N1121.42 (9)
O1—C1—C10121.47 (8)C13—C12—C11120.37 (10)
C3—C2—O1110.50 (8)C13—C12—H12119.8
C3—C2—C17133.13 (9)C11—C12—H12119.8
O1—C2—C17116.36 (8)C14—C13—C12119.97 (11)
C2—C3—C4106.32 (8)C14—C13—H13120.0
C2—C3—H3126.8C12—C13—H13120.0
C4—C3—H3126.8C15—C14—C13119.64 (10)
C1—C4—C3106.46 (8)C15—C14—H14120.2
C1—C4—C5121.28 (8)C13—C14—H14120.2
C3—C4—C5132.22 (8)C14—C15—C16121.15 (10)
C4—C5—C18107.45 (8)C14—C15—H15119.4
C4—C5—C6109.46 (8)C16—C15—H15119.4
C18—C5—C6113.92 (8)C15—C16—C11119.18 (10)
C4—C5—H5108.6C15—C16—H16120.4
C18—C5—H5108.6C11—C16—H16120.4
C6—C5—H5108.6C2—C17—H17A109.5
C7—C6—C5111.40 (8)C2—C17—H17B109.5
C7—C6—C9102.38 (7)H17A—C17—H17B109.5
C5—C6—C9118.72 (8)C2—C17—H17C109.5
C7—C6—H6107.9H17A—C17—H17C109.5
C5—C6—H6107.9H17B—C17—H17C109.5
C9—C6—H6107.9O4—C18—O5124.84 (10)
O2—C7—N1126.77 (9)O4—C18—C5123.54 (10)
O2—C7—C6125.30 (9)O5—C18—C5111.55 (8)
N1—C7—C6107.91 (8)O5—C19—C20106.88 (9)
N1—C8—C9102.56 (7)O5—C19—H19A110.3
N1—C8—H8A111.3C20—C19—H19A110.3
C9—C8—H8A111.3O5—C19—H19B110.3
N1—C8—H8B111.3C20—C19—H19B110.3
C9—C8—H8B111.3H19A—C19—H19B108.6
H8A—C8—H8B109.2C19—C20—H20A109.5
C8—C9—C10109.49 (8)C19—C20—H20B109.5
C8—C9—C6102.03 (7)H20A—C20—H20B109.5
C10—C9—C6114.13 (7)C19—C20—H20C109.5
C8—C9—H9110.3H20A—C20—H20C109.5
C10—C9—H9110.3H20B—C20—H20C109.5
C6—C9—H9110.3C7—N1—C11126.27 (8)
O3—C10—C1123.57 (9)C7—N1—C8111.65 (8)
O3—C10—C9121.65 (8)C11—N1—C8121.13 (8)
C1—C10—C9114.77 (8)C2—O1—C1106.42 (7)
C12—C11—C16119.66 (9)C18—O5—C19116.94 (8)
Hydrogen-bond geometry (Å, º) top
Cg1 and Cg4 are the centroids of the furan (O1/C1–C4) and phenyl (C11–C16) rings, respectively.
D—H···AD—HH···AD···AD—H···A
C14—H14···O1i0.952.533.4766 (16)172
C17—H17A···O4ii0.982.513.4913 (18)176
C17—H17B···O2iii0.982.313.2441 (15)159
C17—H17C···O1iv0.982.573.4232 (14)145
C19—H19B···O1v0.992.543.5181 (17)168
C6—H6···Cg4vi1.002.713.5892 (14)146
C14—H14···Cg1i0.952.933.8320 (16)159
Symmetry codes: (i) −x+2, −y+1, −z+1; (ii) x+1, y, z; (iii) −x+1, −y+1, −z+2; (iv) −x+1, −y+2, −z+2; (v) x−1, y, z; (vi) −x+1, −y+1, −z+1.
Summary of short interatomic contacts (Å) in the title compound 5 top
ContactDistanceSymmetry operation
H17A···O42.511 + x, y, z;
H14···O12.532 - x, 1 - y, 1 - z;
H17C···O12.571 - x, 2 - y, 2 - z;
H17B···O22.311 - x, 1 - y, 2 - z;
H8A···O32.691 - x, 2 - y, 1 - z;
O4···H132.67-1 + x, y, 1 + z;
H20C···C33.09-x, 2 - y, 2 - z;
H6···C162.721 - x, 1 - y, 1 - z;
H17B···H122.47x, y, 1 + z;
H20C···H162.56-1 + x, 1 + y, z.
 

Funding information

The authors are grateful to the Ministry of Education and Science of the Russian Federation [award No. 075–03-2020–223 (FSSF-2020–0017)] for financial support of this research.

References

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ISSN: 2056-9890
Volume 77| Part 2| February 2021| Pages 86-90
https://doi.org/10.1107/S2056989020016801
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