(1'S,6'S,8'S,9'R)-9'-Bromo-12'-oxa-spiro-[1,3-dioxolane-2,4'-tricyclo-[6.3.1.0(1,6)]dodeca-ne].

In an endeavor directed towards the construction of the oxabicyclic[3.2.1]octane segment present in the bioactive natural products of cortistatins and icetexanes genre, the title compound, C(13)H(19)BrO(3), was synthesized from (4aR,9aS)-1,3,4,4a,5,6,9,9a-octa-hydro-spiro-[benzo[7]annulene-2,2'-[1,3]dioxolane]-4a-ol via a transannular bromo-etherification protocol. The six-membered ring adopts a twist-boat conformation, while the fused cycloheptane ring adopts a chair conformation. The crystal packing is effected through two distinct inter-molecular C-H⋯O hydrogen-bond patterns and mol-ecules are arranged to define an inter-esting motif along the b axis.

Related literature

For the isolation and biological activity of cortistatins, see: Aoki et al. (2006 ▶, 2007 ▶); Watanabe et al. (2007 ▶); Zhao (2010 ▶) and for icetexanes, see: Esquivel et al. (1995 ▶); Uchiyama et al. (2005 ▶). For synthetic approaches towards the construction of the oxabicyclic core of cortistatins, see: Zhao (2010 ▶); Hardin Narayan et al. (2010 ▶) and references cited therein. For their use in the treatment of blindness, see: Czako et al. (2009 ▶). For the construction of relevant 6/7 fused-ring systems involving ring-closing metathesis, see: Mehta & Likhite (2008 ▶, 2009 ▶). For an example of the exploitation of transannular bromo­etherification towards natural products synthesis, see: Mehta & Sen (2010 ▶); Mehta & Yaragorla (2011 ▶).

Experimental

Crystal data

C13H19BrO3

M = 303.19

Monoclinic,

a = 11.0159 (3) Å

b = 12.6619 (3) Å

c = 10.2763 (2) Å

β = 117.044 (1)°

V = 1276.63 (5) Å3

Z = 4

Mo Kα radiation

μ = 3.21 mm−1

T = 296 K

0.30 × 0.20 × 0.15 mm

Data collection

Bruker APEXII CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T min = 0.446, T max = 0.644

11338 measured reflections

2368 independent reflections

1859 reflections with I > 2σ(I)

R int = 0.027

Refinement

R[F 2 > 2σ(F 2)] = 0.030

wR(F 2) = 0.076

S = 1.02

2368 reflections

154 parameters

?

Δρmax = 0.25 e Å−3

Δρmin = −0.32 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: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812029777/ds2204sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812029777/ds2204Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536812029777/ds2204Isup3.cml

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

C13H19BrO3	F(000) = 624
Mr = 303.19	Dx = 1.577 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 4277 reflections
a = 11.0159 (3) Å	θ = 2.6–24.2°
b = 12.6619 (3) Å	µ = 3.21 mm−1
c = 10.2763 (2) Å	T = 296 K
β = 117.044 (1)°	Block, colorless
V = 1276.63 (5) Å3	0.30 × 0.20 × 0.15 mm
Z = 4

Bruker APEXII CCD diffractometer	2368 independent reflections
Radiation source: fine-focus sealed tube	1859 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.027
φ and ω scans	θmax = 25.4°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −13→12
Tmin = 0.446, Tmax = 0.644	k = −15→14
11338 measured reflections	l = −9→12

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.030	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.076	w = 1/[σ2(Fo2) + (0.0436P)2 + 0.2892P] where P = (Fo2 + 2Fc2)/3
S = 1.02	(Δ/σ)max = 0.001
2368 reflections	Δρmax = 0.25 e Å−3
154 parameters	Δρmin = −0.32 e Å−3
0 restraints

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

	x	y	z	Uiso*/Ueq
Br1	0.70444 (3)	0.11259 (2)	0.71170 (3)	0.06222 (13)
O1	0.66345 (15)	0.35583 (12)	0.61783 (15)	0.0391 (4)
O2	0.7122 (2)	0.73040 (14)	0.57865 (18)	0.0640 (5)
O3	0.84162 (18)	0.72842 (13)	0.82550 (18)	0.0529 (4)
C1	0.6947 (2)	0.24005 (18)	0.8181 (2)	0.0424 (5)
H1	0.6541	0.2205	0.8820	0.051*
C11	0.6034 (2)	0.32101 (18)	0.7079 (2)	0.0404 (5)
H11	0.5125	0.2915	0.6480	0.048*
C13	0.7789 (3)	0.8290 (2)	0.7886 (3)	0.0547 (7)
H13A	0.8441	0.8848	0.8377	0.066*
H13B	0.7043	0.8344	0.8138	0.066*
C4	0.7757 (2)	0.42229 (17)	0.7136 (2)	0.0348 (5)
C2	0.8358 (2)	0.2838 (2)	0.9109 (3)	0.0479 (6)
H2A	0.8985	0.2259	0.9566	0.057*
H2B	0.8345	0.3275	0.9878	0.057*
C7	0.7737 (2)	0.66148 (18)	0.7019 (2)	0.0439 (5)
C5	0.8222 (3)	0.48727 (18)	0.6187 (3)	0.0482 (6)
H5A	0.8906	0.4482	0.6038	0.058*
H5B	0.7453	0.4997	0.5239	0.058*
C3	0.8863 (2)	0.34948 (19)	0.8204 (3)	0.0439 (5)
H3A	0.9638	0.3916	0.8854	0.053*
H3B	0.9165	0.3025	0.7663	0.053*
C9	0.7113 (2)	0.49168 (18)	0.7904 (2)	0.0371 (5)
H9	0.7779	0.5045	0.8922	0.044*
C8	0.6607 (2)	0.59613 (19)	0.7111 (3)	0.0463 (6)
H8A	0.6205	0.6371	0.7613	0.056*
H8B	0.5900	0.5822	0.6130	0.056*
C6	0.8809 (3)	0.59178 (19)	0.6909 (3)	0.0510 (6)
H6A	0.9192	0.6282	0.6350	0.061*
H6B	0.9540	0.5790	0.7881	0.061*
C12	0.7281 (3)	0.8340 (2)	0.6265 (3)	0.0637 (7)
H12A	0.6419	0.8713	0.5805	0.076*
H12B	0.7934	0.8703	0.6032	0.076*
C10	0.5940 (2)	0.4216 (2)	0.7848 (3)	0.0467 (6)
H10A	0.6061	0.4061	0.8825	0.056*
H10B	0.5065	0.4560	0.7300	0.056*

	U11	U22	U33	U12	U13	U23
Br1	0.0895 (3)	0.04123 (17)	0.0633 (2)	−0.00573 (13)	0.04119 (18)	−0.00022 (12)
O1	0.0431 (9)	0.0423 (8)	0.0294 (8)	−0.0076 (7)	0.0142 (7)	−0.0022 (6)
O2	0.0890 (14)	0.0478 (10)	0.0373 (10)	−0.0019 (10)	0.0129 (10)	0.0008 (8)
O3	0.0545 (10)	0.0443 (9)	0.0425 (9)	0.0021 (8)	0.0068 (8)	−0.0056 (7)
C1	0.0489 (14)	0.0453 (13)	0.0364 (12)	−0.0032 (10)	0.0223 (11)	0.0011 (10)
C11	0.0321 (12)	0.0482 (13)	0.0380 (13)	−0.0066 (10)	0.0134 (10)	0.0023 (10)
C13	0.0602 (17)	0.0420 (14)	0.0590 (17)	−0.0012 (12)	0.0246 (14)	−0.0077 (12)
C4	0.0335 (12)	0.0383 (11)	0.0327 (12)	−0.0032 (9)	0.0153 (10)	−0.0047 (10)
C2	0.0453 (14)	0.0514 (14)	0.0364 (13)	0.0075 (11)	0.0094 (11)	0.0049 (11)
C7	0.0488 (14)	0.0384 (12)	0.0372 (13)	−0.0014 (11)	0.0132 (11)	−0.0032 (10)
C5	0.0584 (16)	0.0430 (13)	0.0569 (15)	−0.0040 (11)	0.0382 (13)	−0.0051 (11)
C3	0.0313 (12)	0.0458 (12)	0.0504 (14)	0.0011 (10)	0.0149 (11)	−0.0047 (11)
C9	0.0325 (12)	0.0443 (12)	0.0337 (12)	0.0026 (9)	0.0144 (10)	−0.0042 (10)
C8	0.0370 (12)	0.0462 (14)	0.0493 (15)	0.0067 (10)	0.0140 (11)	−0.0024 (11)
C6	0.0516 (15)	0.0453 (14)	0.0621 (16)	−0.0098 (11)	0.0311 (13)	−0.0067 (12)
C12	0.075 (2)	0.0490 (16)	0.0596 (17)	0.0066 (14)	0.0237 (15)	0.0063 (13)
C10	0.0399 (13)	0.0549 (14)	0.0508 (14)	0.0033 (11)	0.0255 (12)	0.0035 (12)

Br1—C1	1.979 (2)	C2—H2B	0.9700
O1—C11	1.430 (3)	C7—C6	1.519 (3)
O1—C4	1.449 (3)	C7—C8	1.533 (4)
O2—C12	1.384 (3)	C5—C6	1.511 (3)
O2—C7	1.430 (3)	C5—H5A	0.9700
O3—C13	1.416 (3)	C5—H5B	0.9700
O3—C7	1.424 (3)	C3—H3A	0.9700
C1—C2	1.512 (3)	C3—H3B	0.9700
C1—C11	1.519 (3)	C9—C8	1.520 (3)
C1—H1	0.9800	C9—C10	1.547 (3)
C11—C10	1.528 (3)	C9—H9	0.9800
C11—H11	0.9800	C8—H8A	0.9700
C13—C12	1.498 (4)	C8—H8B	0.9700
C13—H13A	0.9700	C6—H6A	0.9700
C13—H13B	0.9700	C6—H6B	0.9700
C4—C3	1.524 (3)	C12—H12A	0.9700
C4—C5	1.531 (3)	C12—H12B	0.9700
C4—C9	1.552 (3)	C10—H10A	0.9700
C2—C3	1.529 (3)	C10—H10B	0.9700
C2—H2A	0.9700
C11—O1—C4	104.04 (15)	C4—C5—H5A	109.5
C12—O2—C7	109.37 (19)	C6—C5—H5B	109.5
C13—O3—C7	107.58 (18)	C4—C5—H5B	109.5
C2—C1—C11	111.43 (19)	H5A—C5—H5B	108.1
C2—C1—Br1	110.40 (16)	C4—C3—C2	111.99 (18)
C11—C1—Br1	108.80 (15)	C4—C3—H3A	109.2
C2—C1—H1	108.7	C2—C3—H3A	109.2
C11—C1—H1	108.7	C4—C3—H3B	109.2
Br1—C1—H1	108.7	C2—C3—H3B	109.2
O1—C11—C1	110.25 (17)	H3A—C3—H3B	107.9
O1—C11—C10	103.78 (17)	C8—C9—C10	112.51 (19)
C1—C11—C10	110.77 (19)	C8—C9—C4	111.12 (18)
O1—C11—H11	110.6	C10—C9—C4	102.94 (18)
C1—C11—H11	110.6	C8—C9—H9	110.0
C10—C11—H11	110.6	C10—C9—H9	110.0
O3—C13—C12	103.1 (2)	C4—C9—H9	110.0
O3—C13—H13A	111.2	C9—C8—C7	113.1 (2)
C12—C13—H13A	111.2	C9—C8—H8A	108.9
O3—C13—H13B	111.2	C7—C8—H8A	108.9
C12—C13—H13B	111.2	C9—C8—H8B	108.9
H13A—C13—H13B	109.1	C7—C8—H8B	108.9
O1—C4—C3	107.08 (17)	H8A—C8—H8B	107.8
O1—C4—C5	107.98 (17)	C5—C6—C7	111.8 (2)
C3—C4—C5	113.22 (18)	C5—C6—H6A	109.3
O1—C4—C9	103.17 (16)	C7—C6—H6A	109.3
C3—C4—C9	112.15 (18)	C5—C6—H6B	109.3
C5—C4—C9	112.49 (18)	C7—C6—H6B	109.3
C1—C2—C3	111.68 (18)	H6A—C6—H6B	107.9
C1—C2—H2A	109.3	O2—C12—C13	106.1 (2)
C3—C2—H2A	109.3	O2—C12—H12A	110.5
C1—C2—H2B	109.3	C13—C12—H12A	110.5
C3—C2—H2B	109.3	O2—C12—H12B	110.5
H2A—C2—H2B	107.9	C13—C12—H12B	110.5
O3—C7—O2	105.78 (18)	H12A—C12—H12B	108.7
O3—C7—C6	107.5 (2)	C11—C10—C9	104.20 (17)
O2—C7—C6	111.1 (2)	C11—C10—H10A	110.9
O3—C7—C8	112.2 (2)	C9—C10—H10A	110.9
O2—C7—C8	108.2 (2)	C11—C10—H10B	110.9
C6—C7—C8	111.80 (19)	C9—C10—H10B	110.9
C6—C5—C4	110.50 (19)	H10A—C10—H10B	108.9
C6—C5—H5A	109.5

D—H···A	D—H	H···A	D···A	D—H···A
C11—H11···O2i	0.98	2.53	3.445 (3)	156
C1—H1···O1ii	0.98	2.57	3.471 (3)	153

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C11—H11⋯O2i	0.98	2.53	3.445 (3)	156
C1—H1⋯O1ii	0.98	2.57	3.471 (3)	153

Symmetry codes: (i) ; (ii) .