Spiro­[cyclo­pentane-1,11′-hexa­cyclo[7.6.0.01,6.06,13.08,12.010,14]penta­deca­ne]-7′,15′-dione

Kotha, S.; Gunta, R.; Cheekatla, S.R.; Mhatre, D.S.

doi:10.1107/S2414314618015900

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 3| Part 11| November 2018| x181590

https://doi.org/10.1107/S2414314618015900

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Spiro[cyclopentane-1,11′-hexacyclo[7.6.0.0^1,6.0^6,13.0^8,12.0^10,14]pentadecane]-7′,15′-dione

Sambasivarao Kotha,^a ^* Rama Gunta,^a Subba Rao Cheekatla ^a and Darshan S. Mhatre ^a

^aDepartment of Chemistry, Indian Institute of Technology - Bombay, Powai, Mumbai, 400 076, India
^*Correspondence e-mail: srk@chem.iitb.ac.in

Edited by I. Brito, University of Antofagasta, Chile (Received 18 September 2018; accepted 9 November 2018; online 27 November 2018)

An unusual rearrangement of spiro cage dione to a trishomocubane derivatives is reported by acid-catalysed rearrangement with the aid of BF₃·OEt₂ in benzene (solvent) reflux conditions. Here, the molecular structure of cage molecule C₁₉H₂₂O₂ (major product) consists of five-membered rings, which adopt an envelope conformation and six-membered rings adopt a chair or boat conformation. The Cremer & Pople puckering parameters of all four six-membered rings are calculated.

Keywords: crystal structure; cage molecule; trishomocubane; Lewis acid.

CCDC reference: 1878138

Structure description

D₃-Trishomocubane and its derivatives are of interest for their use as targets for pharmaceutical applications (Liu et al., 2001 ), in medicinal chemistry (Oliver et al., 1991 ) as well as in asymmetric catalysis (Levandovsky et al., 2010 ; Sharapa et al., 2012 ). Several amino functionalized D₃-trishomocubane derivatives show significant biological activity and are NMDA receptor antagonists. In addition, some of them exhibit potent anti-TB activity, act as P₂X₇ receptor antagonists and exhibit anti-Parkinson's activity (Geldenhuys et al., 2005 ).

As part of our major program on cage molecules, which involves the design of unusual polycyclic cage frameworks, for example, D₃-trishomocubanes by the rearrangement approach (Kotha et al., 2018 ) and we present herein the synthesis of the title cage compound II (Fig. 1), which was prepared (Fig. 2) from cheap and commercially available starting materials such as 1,4-hydroquinone in eight steps via Claisen rearrangement, Diels–Alder reaction and ring-closing metathesis (RCM) followed by acid-promoted rearrangement with Lewis acid (Kotha & Dipak, 2006 ).

Figure 1
The molecular structure of the title compound II with displacement ellipsoids drawn at the 50% probability level.

Figure 2
Lewis acid-promoted rearrangement of the cage dione I.

The molecular structure of II is made up of fused five- and six-membered rings that are joined into a compact cage system. All five-membered rings adopt an envelope conformation, whereas the six-membered rings are in chair or boat conformations. The Cremer & Pople puckering parameters of three six-membered rings, namely, C2–C7, C2/C3/C9/C10/C6/C7 and C3–C6/C10/C9 are Q = 1.110 (2) Å, θ = 89.25 (10)° and φ = 15.37 (12)°; Q = 1.112 (2) Å, θ = 89.98 (10)° and φ = 285.71 (12)°; and Q = 1.114 (2) Å, θ = 90.57 (10)° and φ = 44.48 (12)° respectively. These six-membered rings all exhibit a boat conformation. The other six-membered ring C4/C5/C12–C15 is in a chair conformation with puckering parameters Q = 0.530 (3) Å. θ = 7.1 (3)° and φ = 216 (2)°.

Synthesis and crystallization

Compound II can be prepared via Lewis acid-promoted rearrangement (Fig. 2) of the cage [4.4.2]propellane I with the aid of BF₃·OEt₂ in the presence of benzene as a solvent. Spiro cage dione I (200 mg, 0.70 mmol) was added to a stirred solution of anhydrous BF₃·OEt₂ (1 mL) in dry benzene (10 mL) at room temperature. Next, the resulting reaction mixture was refluxed for two days. After completion of the reaction (TLC monitoring), the reaction mixture was quenched with a saturated aqueous NaHCO₃ solution and extracted with benzene. The combined organic layers were washed with water and brine solution then dried over anhydrous Na₂SO_4. After removal of the solvent under vacuum, the resulting crude residue was subjected to silica gel column chromatography by using 5% ethyl acetate in petroleum ether as an eluent to deliver the desired rearranged cage ketone III (57 mg, 23%) containing a phenyl group as a colourless liquid. Continuous elution with 10% ethyl acetate in petroleum ether delivered the rearranged cage dione II (82 mg, 41%) as a colourless crystalline solid. Recrystallization of a column-purified II from a mixture of ethyl acetate and hexane (1:2) solvents gave crystals suitable for X-ray analysis. M.p. 409–411 K. IR (neat, cm⁻¹) 2926, 2857, 1751, 1450, 1294, 1076; ¹H NMR (500 MHz, CDCl₃ p.p.m.): δ 2.23–2.26 (m, 6H), 1.83 (d, J = 13.5 Hz, 2H), 1.69–1.62 (m, 2H), 1.49–1.42 (m, 10H), 1.15–1.12 (m, 2H); ¹³C NMR (125 MHz, CDCl₃, p.p.m.): δ 213.1, 60.5, 50.6, 48.6, 48.4, 42.8, 32.5, 26.1, 22.2, 21.9; HRMS (ESI, Q-TOF) m/z calculated for C₁₉H₂₂O₂ [M + Na] ⁺ 305.1512; found: 305.1514.

Melting points were recorded on a Veego VMP–CMP melting point apparatus and are uncorrected. Nuclear Magnetic Resonance (NMR) spectra were recorded on a Bruker (Avance III^TM500) spectrometer operated at 500 MHz for ¹H and 125.7 MHz for ¹³C nuclei.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1.

Table 1
Experimental details

Crystal data
Chemical formula	C₁₉H₂₂O₂
M_r	282.36
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	150
a, b, c (Å)	10.8650 (8), 14.3936 (9), 9.8008 (8)
β (°)	111.680 (9)
V (Å³)	1424.3 (2)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	0.08
Crystal size (mm)	0.14 × 0.11 × 0.09

Data collection
Diffractometer	Rigaku Saturn724+
Absorption correction	Multi-scan (CrysAlis PRO; Rigaku OD, 2018 $[Rigaku OD (2018). CrysAlis PRO. Rigaku Oxford Diffraction, Yarnton, England.]$ )
T_min, T_max	0.740, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	4407, 2470, 1877
R_int	0.050
(sin θ/λ)_max (Å⁻¹)	0.594

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.052, 0.140, 1.05
No. of reflections	2470
No. of parameters	190
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.25, −0.28
Computer programs: CrysAlis PRO (Rigaku OD, 2018 $[Rigaku OD (2018). CrysAlis PRO. Rigaku Oxford Diffraction, Yarnton, England.]$ ), SHELXT (Sheldrick, 2015a ), SHELXL (Sheldrick, 2015b ) and OLEX2 (Dolomanov et al., 2009 ).

Structural data

CCDC reference: 1878138

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2414314618015900/bx4013sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314618015900/bx4013Isup3.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2414314618015900/bx4013Isup3.cml

checkCIF report

Computing details top

Data collection: CrysAlis PRO (Rigaku OD, 2018); cell refinement: CrysAlis PRO (Rigaku OD, 2018); data reduction: CrysAlis PRO (Rigaku OD, 2018); program(s) used to solve structure: ShelXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: OLEX2 (Dolomanov et al., 2009).

Spiro[cyclopentane-1,11'-hexacyclo[7.6.0.0^1,6.0^6,13.0^8,12.0^10,14]pentadecane]-7',15'-dione top

Crystal data top

C₁₉H₂₂O₂	D_x = 1.317 Mg m⁻³
M_r = 282.36	Melting point = 409–411 K
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
a = 10.8650 (8) Å	Cell parameters from 2620 reflections
b = 14.3936 (9) Å	θ = 2.5–31.0°
c = 9.8008 (8) Å	µ = 0.08 mm⁻¹
β = 111.680 (9)°	T = 150 K
V = 1424.3 (2) Å³	Block, colourless
Z = 4	0.14 × 0.11 × 0.09 mm
F(000) = 608

Data collection top

Rigaku Saturn724+ diffractometer	2470 independent reflections
Radiation source: fine-focus sealed X-ray tube	1877 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.050
ω scans	θ_max = 25.0°, θ_min = 2.7°
Absorption correction: multi-scan (CrysAlisPro; Rigaku OD, 2018)	h = −12→8
T_min = 0.740, T_max = 1.000	k = −11→17
4407 measured reflections	l = −10→11

Refinement top

Refinement on F²	Primary atom site location: dual
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.052	H-atom parameters constrained
wR(F²) = 0.140	w = 1/[σ²(F_o²) + (0.0668P)² + 0.4068P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max < 0.001
2470 reflections	Δρ_max = 0.25 e Å⁻³
190 parameters	Δρ_min = −0.28 e Å⁻³
0 restraints

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.

Refinement. All H atoms were placed in geometrically calculated positions and refined using a riding model with C–H distances of 1.00 Å for all H atoms bound to tertiary C(sp³) atoms and 0.99 Å for H atoms bound to secondary C(sp³) atoms. Isotropic displacement parameters for H atoms were calculated as U_iso(H) = 1.2U_eq(C).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.66123 (15)	0.57866 (10)	0.78083 (19)	0.0336 (4)
O2	0.67492 (16)	0.18936 (11)	0.86490 (19)	0.0361 (5)
C1	0.6053 (2)	0.50462 (15)	0.7681 (2)	0.0228 (5)
C2	0.4704 (2)	0.48099 (15)	0.7682 (2)	0.0236 (5)
H2	0.420116	0.532032	0.793568	0.028*
C3	0.4940 (2)	0.39008 (14)	0.8618 (3)	0.0250 (5)
H3	0.481313	0.397490	0.957203	0.030*
C4	0.6387 (2)	0.35801 (14)	0.8782 (2)	0.0252 (5)
C5	0.6500 (2)	0.40821 (14)	0.7433 (2)	0.0217 (5)
C6	0.5219 (2)	0.36927 (14)	0.6173 (2)	0.0218 (5)
H6	0.531107	0.361861	0.520102	0.026*
C7	0.4066 (2)	0.43687 (14)	0.6154 (2)	0.0224 (5)
H7	0.375903	0.481631	0.531443	0.027*
C8	0.2984 (2)	0.37374 (15)	0.6313 (3)	0.0254 (5)
C9	0.3986 (2)	0.31667 (15)	0.7546 (2)	0.0269 (6)
H9	0.359305	0.269925	0.802299	0.032*
C10	0.4915 (2)	0.27694 (14)	0.6830 (3)	0.0251 (5)
H10	0.457245	0.223742	0.613611	0.030*
C11	0.6139 (2)	0.25960 (15)	0.8169 (2)	0.0259 (5)
C12	0.7534 (2)	0.37557 (16)	1.0209 (3)	0.0313 (6)
H12A	0.747001	0.333189	1.097601	0.038*
H12B	0.749162	0.440225	1.053410	0.038*
C13	0.8851 (2)	0.35997 (18)	1.0017 (3)	0.0364 (6)
H13A	0.958731	0.376379	1.094051	0.044*
H13B	0.893859	0.293352	0.981774	0.044*
C14	0.8961 (2)	0.41781 (17)	0.8765 (3)	0.0335 (6)
H14A	0.982037	0.404682	0.866980	0.040*
H14B	0.894383	0.484567	0.900056	0.040*
C15	0.7839 (2)	0.39734 (16)	0.7303 (3)	0.0273 (5)
H15A	0.790035	0.440386	0.654310	0.033*
H15B	0.793140	0.333131	0.699164	0.033*
C16	0.2179 (2)	0.31748 (16)	0.4922 (3)	0.0308 (6)
H16A	0.255017	0.326049	0.414784	0.037*
H16B	0.219347	0.250448	0.515439	0.037*
C17	0.0770 (2)	0.35547 (18)	0.4420 (3)	0.0346 (6)
H17A	0.066801	0.411673	0.380529	0.041*
H17B	0.011547	0.308245	0.385971	0.041*
C18	0.0616 (2)	0.37849 (18)	0.5865 (3)	0.0366 (6)
H18A	0.048415	0.321521	0.636087	0.044*
H18B	−0.013808	0.421180	0.571085	0.044*
C19	0.1933 (2)	0.42530 (17)	0.6750 (3)	0.0320 (6)
H19A	0.213210	0.419146	0.781667	0.038*
H19B	0.190743	0.492109	0.650138	0.038*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0352 (10)	0.0194 (9)	0.0443 (11)	−0.0054 (7)	0.0125 (8)	−0.0020 (7)
O2	0.0463 (10)	0.0204 (9)	0.0435 (11)	0.0061 (8)	0.0188 (8)	0.0057 (8)
C1	0.0275 (12)	0.0199 (12)	0.0184 (12)	0.0011 (9)	0.0057 (9)	0.0006 (9)
C2	0.0281 (12)	0.0189 (11)	0.0262 (12)	0.0020 (9)	0.0127 (10)	−0.0013 (9)
C3	0.0349 (13)	0.0208 (11)	0.0242 (12)	−0.0009 (9)	0.0168 (10)	−0.0018 (9)
C4	0.0339 (13)	0.0193 (11)	0.0246 (13)	0.0014 (9)	0.0132 (10)	0.0019 (9)
C5	0.0245 (12)	0.0215 (11)	0.0194 (12)	0.0000 (9)	0.0083 (9)	0.0006 (9)
C6	0.0246 (11)	0.0214 (11)	0.0209 (12)	−0.0015 (9)	0.0102 (10)	−0.0010 (9)
C7	0.0223 (11)	0.0219 (11)	0.0242 (12)	−0.0001 (9)	0.0100 (9)	0.0006 (9)
C8	0.0256 (12)	0.0253 (12)	0.0294 (13)	−0.0034 (9)	0.0150 (10)	−0.0055 (10)
C9	0.0336 (13)	0.0234 (12)	0.0309 (14)	−0.0071 (10)	0.0203 (11)	−0.0031 (10)
C10	0.0304 (12)	0.0187 (11)	0.0297 (13)	−0.0029 (9)	0.0154 (10)	−0.0031 (9)
C11	0.0358 (13)	0.0186 (12)	0.0283 (13)	−0.0004 (10)	0.0177 (11)	0.0033 (10)
C12	0.0409 (14)	0.0274 (12)	0.0225 (13)	0.0024 (10)	0.0082 (11)	0.0015 (10)
C13	0.0333 (13)	0.0368 (14)	0.0301 (15)	0.0059 (11)	0.0012 (11)	0.0015 (11)
C14	0.0246 (13)	0.0370 (14)	0.0339 (14)	0.0003 (10)	0.0051 (11)	−0.0046 (11)
C15	0.0262 (12)	0.0287 (12)	0.0278 (13)	0.0004 (10)	0.0108 (10)	0.0001 (10)
C16	0.0291 (13)	0.0308 (13)	0.0360 (14)	−0.0068 (10)	0.0161 (11)	−0.0080 (11)
C17	0.0302 (13)	0.0396 (14)	0.0362 (15)	−0.0073 (11)	0.0150 (11)	−0.0056 (11)
C18	0.0279 (13)	0.0429 (15)	0.0438 (16)	−0.0055 (11)	0.0190 (12)	−0.0070 (12)
C19	0.0297 (13)	0.0350 (13)	0.0364 (15)	−0.0006 (10)	0.0181 (11)	−0.0052 (11)

Geometric parameters (Å, º) top

O1—C1	1.210 (3)	C12—H12A	0.9900
O2—C11	1.205 (3)	C12—H12B	0.9900
C1—C2	1.505 (3)	C12—C13	1.528 (3)
C1—C5	1.519 (3)	C13—H13A	0.9900
C2—H2	1.0000	C13—H13B	0.9900
C2—C3	1.564 (3)	C14—C13	1.523 (3)
C2—C7	1.536 (3)	C14—H14A	0.9900
C3—H3	1.0000	C14—H14B	0.9900
C3—C4	1.589 (3)	C15—C5	1.514 (3)
C3—C9	1.578 (3)	C15—C14	1.528 (3)
C4—C12	1.512 (3)	C15—H15A	0.9900
C5—C4	1.550 (3)	C15—H15B	0.9900
C5—C6	1.583 (3)	C16—H16A	0.9900
C6—H6	1.0000	C16—H16B	0.9900
C6—C7	1.580 (3)	C16—C17	1.527 (3)
C6—C10	1.564 (3)	C17—H17A	0.9900
C7—H7	1.0000	C17—H17B	0.9900
C7—C8	1.538 (3)	C18—C17	1.523 (3)
C8—C9	1.532 (3)	C18—H18A	0.9900
C8—C16	1.548 (3)	C18—H18B	0.9900
C9—H9	1.0000	C19—C8	1.550 (3)
C10—C9	1.538 (3)	C19—C18	1.528 (3)
C10—H10	1.0000	C19—H19A	0.9900
C11—C4	1.523 (3)	C19—H19B	0.9900
C11—C10	1.505 (3)

O1—C1—C2	130.6 (2)	C11—C10—C6	104.29 (17)
O1—C1—C5	130.0 (2)	C11—C10—C9	100.46 (18)
C2—C1—C5	99.37 (17)	C11—C10—H10	116.9
C1—C2—H2	117.1	O2—C11—C4	129.4 (2)
C1—C2—C3	103.90 (17)	O2—C11—C10	131.4 (2)
C1—C2—C7	100.46 (17)	C10—C11—C4	99.23 (17)
C3—C2—H2	117.1	C4—C12—H12A	109.5
C7—C2—H2	117.1	C4—C12—H12B	109.5
C7—C2—C3	98.24 (16)	C4—C12—C13	110.5 (2)
C2—C3—H3	114.2	H12A—C12—H12B	108.1
C2—C3—C4	104.15 (16)	C13—C12—H12A	109.5
C2—C3—C9	104.15 (18)	C13—C12—H12B	109.5
C4—C3—H3	114.2	C12—C13—H13A	109.2
C9—C3—H3	114.2	C12—C13—H13B	109.2
C9—C3—C4	104.79 (17)	H13A—C13—H13B	107.9
C5—C4—C3	99.51 (16)	C14—C13—C12	112.02 (19)
C11—C4—C3	101.89 (17)	C14—C13—H13A	109.2
C11—C4—C5	98.93 (17)	C14—C13—H13B	109.2
C12—C4—C3	119.41 (19)	C13—C14—H14A	109.2
C12—C4—C5	114.43 (18)	C13—C14—H14B	109.2
C12—C4—C11	119.06 (18)	C13—C14—C15	112.13 (19)
C1—C5—C4	99.11 (17)	H14A—C14—H14B	107.9
C1—C5—C6	101.95 (16)	C15—C14—H14A	109.2
C4—C5—C6	100.16 (16)	C15—C14—H14B	109.2
C15—C5—C1	118.81 (18)	C5—C15—C14	111.09 (19)
C15—C5—C4	113.84 (18)	C5—C15—H15A	109.4
C15—C5—C6	119.54 (18)	C5—C15—H15B	109.4
C5—C6—H6	114.3	C14—C15—H15A	109.4
C7—C6—C5	104.84 (16)	C14—C15—H15B	109.4
C7—C6—H6	114.3	H15A—C15—H15B	108.0
C10—C6—C5	103.79 (17)	C8—C16—H16A	110.6
C10—C6—H6	114.3	C8—C16—H16B	110.6
C10—C6—C7	103.97 (16)	H16A—C16—H16B	108.7
C2—C7—C6	99.94 (16)	C17—C16—C8	105.67 (18)
C2—C7—H7	115.4	C17—C16—H16A	110.6
C2—C7—C8	103.39 (17)	C17—C16—H16B	110.6
C6—C7—H7	115.4	C16—C17—H17A	111.2
C8—C7—C6	105.47 (16)	C16—C17—H17B	111.2
C8—C7—H7	115.4	H17A—C17—H17B	109.1
C7—C8—C16	115.11 (18)	C18—C17—C16	102.7 (2)
C7—C8—C19	114.46 (18)	C18—C17—H17A	111.2
C9—C8—C7	92.90 (17)	C18—C17—H17B	111.2
C9—C8—C16	114.81 (19)	C17—C18—H18A	111.2
C9—C8—C19	114.79 (19)	C17—C18—H18B	111.2
C16—C8—C19	105.03 (18)	C17—C18—C19	102.85 (19)
C3—C9—H9	115.4	H18A—C18—H18B	109.1
C8—C9—C3	105.47 (18)	C19—C18—H18A	111.2
C8—C9—H9	115.4	C19—C18—H18B	111.2
C8—C9—C10	103.50 (18)	C8—C19—H19A	110.7
C10—C9—C3	99.90 (17)	C8—C19—H19B	110.7
C10—C9—H9	115.4	C18—C19—C8	105.26 (19)
C6—C10—H10	116.9	C18—C19—H19A	110.7
C9—C10—C6	98.38 (16)	C18—C19—H19B	110.7
C9—C10—H10	116.9	H19A—C19—H19B	108.8

Funding information

We thank the Defence Research and Development Organization (DRDO, No. ARDB/01/1041849/M/1), New Delhi, for financial assistance. SK thanks the Department of Science and Technology (DST, No. SR/S2/JCB-33/2010) for the award of a J. C. Bose fellowship and Praj industries for the Pramod Chaudhari Chair Professorship (Green Chemistry). RG thanks Indian Institute of Technology (IIT) - Bombay, Mumbai for financial support as an Institute Research Associate (RA) and SRC thanks the University Grants Commission (UGC), New Delhi, for the award of a research fellowship.

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