(2aR*,5S*,6aS*,8aS*,E)-Ethyl 5-hy-droxy-7,7,8a-trimethyl-8-oxo-2,2a,6,6a,7,8,8a,8b-octa-hydro-1H-penta-leno[1,6-bc]oxepine-4-carboxyl-ate.

The title compound, C17H24O5, featuring a 2-carbeth-oxy-3-oxepanone unit in its intra-molecularly O-H⋯O hydrogen-bonded enol form, was obtained via [(CF3CO2)2Rh]2-catal-ysed intra-molecular O-H bond insertion in the α-diazo-ω-hy-droxy-β-ketoester, ethyl 4-[(1S,3aS,6R,6aS)-6-hy-droxy-2,2,3a-trimethyl-3-oxo-octa-hydro-penta-len-1-yl]-2-diazo-3-oxobutano-ate. The seven-membered oxacyclic ring, thus constructed on a cis-fused diquinane platform, was found to adopt a distorted boat-sofa conformation.

Related literature

For rhodium carbenoid-mediated inter­molecular O—H inser­tion reactions and their application to natural product synthesis, see: Paulissen et al. (1973 ▶); Cox et al. (1994 ▶); Haigh (1994 ▶); Aller et al. (1995 ▶); Shi et al. (1995 ▶); Bulugahapitiya et al. (1997 ▶); Moody & Miller (1998 ▶); Nelson et al. (2000 ▶); Medeiros & Wood (2010 ▶); Freeman et al. (2010 ▶); Morton et al. (2012 ▶). For rhodium-catalysed intra­molecular O—H insertion reactions, see: Paulissen et al. (1974 ▶); Moyer et al. (1985 ▶); Moody & Taylor (1987 ▶); Heslin & Moody (1988 ▶); Davies et al. (1990 ▶); Moody et al. (1992 ▶); Sarabia-Garciá et al. (1994) ▶; Pad­wa & Sá (1999 ▶); Im et al. (2005 ▶). For reviews on rhodium-mediated C—H insertion reactions, see: Doyle et al. (2010 ▶); Davies & Morton (2011 ▶). For the con­struction of an angularly fused triquinane skeleton via RhII-catalysed intra­molecular C—H insertion, see: Srikrishna et al. (2012 ▶). For the isolation and synthesis of penifulvin A, see: Shim et al. (2006 ▶); Gaich & Mulzer (2009 ▶); Mehta & Khan (2012 ▶). For the application of p-acetamido­benzene­sulfonyl azide as a diazo trans­fer reagent, see: Baum et al. (1987 ▶). For ring conformations, see: Cremer & Pople (1975 ▶); Boessenkool & Boeyens (1980 ▶).

Experimental

Crystal data

C17H24O5

M = 308.36

Orthorhombic,

a = 8.447 (5) Å

b = 18.454 (14) Å

c = 21.735 (15) Å

V = 3388 (4) Å3

Z = 8

Mo Kα radiation

μ = 0.09 mm−1

T = 291 K

0.20 × 0.18 × 0.08 mm

Data collection

Bruker APEXII CCD diffractometer

Absorption correction: multi-scan (SADABS; Sheldrick, 2003 ▶) T min = 0.983, T max = 0.993

14606 measured reflections

3153 independent reflections

1408 reflections with I > 2σ(I)

R int = 0.087

Refinement

R[F 2 > 2σ(F 2)] = 0.053

wR(F 2) = 0.149

S = 0.89

3153 reflections

207 parameters

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.17 e Å−3

Δρmin = −0.17 e Å−3

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SIR92 (Altomare et al., 1994 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶); software used to prepare material for publication: PLATON (Spek, 2009 ▶).

Click here for additional data file.

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812046776/ds2220sup1.cif

Click here for additional data file.

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812046776/ds2220Isup2.hkl

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

C17H24O5	F(000) = 1328
Mr = 308.36	Dx = 1.209 Mg m−3
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 939 reflections
a = 8.447 (5) Å	θ = 2.8–19.5°
b = 18.454 (14) Å	µ = 0.09 mm−1
c = 21.735 (15) Å	T = 291 K
V = 3388 (4) Å3	Plate, colorless
Z = 8	0.20 × 0.18 × 0.08 mm

Bruker APEXII CCD diffractometer	3153 independent reflections
Radiation source: fine-focus sealed tube	1408 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.087
φ and ω scans	θmax = 25.5°, θmin = 1.9°
Absorption correction: multi-scan (SADABS; Sheldrick, 2003)	h = −10→7
Tmin = 0.983, Tmax = 0.993	k = −22→18
14606 measured reflections	l = −26→26

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)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.149	H atoms treated by a mixture of independent and constrained refinement
S = 0.89	w = 1/[σ2(Fo2) + (0.0717P)2] where P = (Fo2 + 2Fc2)/3
3153 reflections	(Δ/σ)max < 0.001
207 parameters	Δρmax = 0.17 e Å−3
0 restraints	Δρmin = −0.17 e Å−3

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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
O1	0.1027 (3)	0.15812 (15)	1.02261 (10)	0.0990 (9)
O2	0.0947 (2)	0.13477 (12)	0.69261 (9)	0.0655 (6)
H2O	0.125 (4)	0.0976 (18)	0.6660 (15)	0.090 (12)*
O3	0.1391 (2)	−0.00529 (10)	0.80956 (7)	0.0545 (5)
O4	0.1993 (2)	0.01550 (12)	0.64764 (8)	0.0717 (6)
O5	0.2612 (2)	−0.07327 (12)	0.71407 (8)	0.0678 (6)
C1	0.0661 (3)	0.12205 (14)	0.86389 (11)	0.0471 (7)
H1	−0.0058	0.0810	0.8699	0.057*
C2	0.0332 (3)	0.17697 (15)	0.91600 (12)	0.0544 (8)
C3	0.1256 (3)	0.14428 (17)	0.96932 (13)	0.0623 (8)
C4	0.2513 (3)	0.09177 (16)	0.94596 (12)	0.0568 (8)
C5	0.2035 (5)	0.01234 (18)	0.95976 (14)	0.0888 (11)
H5A	0.2518	−0.0039	0.9978	0.107*
H5B	0.0895	0.0083	0.9637	0.107*
C6	0.2602 (5)	−0.03189 (19)	0.90749 (14)	0.0906 (12)
H6A	0.1898	−0.0726	0.9006	0.109*
H6B	0.3655	−0.0504	0.9158	0.109*
C7	0.2627 (3)	0.01697 (15)	0.85202 (12)	0.0575 (8)
H7	0.3661	0.0139	0.8317	0.069*
C8	0.2347 (3)	0.09461 (14)	0.87520 (11)	0.0474 (7)
H8	0.3125	0.1280	0.8574	0.057*
C9	0.4153 (4)	0.1103 (2)	0.97087 (15)	0.0970 (12)
H9A	0.4449	0.1580	0.9573	0.145*
H9B	0.4908	0.0757	0.9559	0.145*
H9C	0.4133	0.1090	1.0150	0.145*
C10	−0.1415 (4)	0.1859 (2)	0.93120 (14)	0.0795 (11)
H10A	−0.1868	0.1394	0.9400	0.119*
H10B	−0.1952	0.2072	0.8967	0.119*
H10C	−0.1527	0.2168	0.9664	0.119*
C11	0.1093 (4)	0.25222 (16)	0.90386 (15)	0.0781 (10)
H11A	0.1031	0.2811	0.9405	0.117*
H11B	0.0537	0.2761	0.8711	0.117*
H11C	0.2183	0.2460	0.8925	0.117*
C12	0.0415 (3)	0.14979 (16)	0.79823 (11)	0.0569 (8)
H12A	−0.0704	0.1595	0.7925	0.068*
H12B	0.0971	0.1955	0.7940	0.068*
C13	0.0951 (3)	0.10042 (16)	0.74780 (12)	0.0510 (7)
C14	0.1445 (3)	0.03157 (16)	0.75362 (11)	0.0512 (7)
C15	0.2038 (3)	−0.00865 (17)	0.70042 (13)	0.0572 (8)
C16	0.3258 (4)	−0.11534 (19)	0.66252 (15)	0.0833 (11)
H16A	0.2406	−0.1329	0.6366	0.100*
H16B	0.3950	−0.0852	0.6378	0.100*
C17	0.4146 (6)	−0.1765 (2)	0.68814 (18)	0.1264 (17)
H17A	0.4935	−0.1587	0.7161	0.190*
H17B	0.4650	−0.2027	0.6554	0.190*
H17C	0.3435	−0.2081	0.7097	0.190*

	U11	U22	U33	U12	U13	U23
O1	0.113 (2)	0.137 (2)	0.0465 (13)	0.0369 (16)	−0.0008 (12)	−0.0152 (14)
O2	0.0791 (15)	0.0722 (16)	0.0452 (12)	0.0013 (12)	−0.0053 (10)	0.0083 (12)
O3	0.0605 (13)	0.0555 (13)	0.0474 (11)	−0.0043 (9)	0.0016 (9)	−0.0012 (9)
O4	0.0820 (16)	0.0883 (16)	0.0448 (12)	0.0032 (12)	0.0027 (10)	−0.0031 (11)
O5	0.0850 (16)	0.0645 (14)	0.0540 (12)	0.0051 (12)	0.0061 (10)	−0.0092 (11)
C1	0.0407 (18)	0.0550 (17)	0.0456 (16)	−0.0004 (13)	−0.0013 (12)	−0.0012 (13)
C2	0.0495 (19)	0.060 (2)	0.0541 (17)	0.0038 (15)	−0.0001 (13)	−0.0068 (15)
C3	0.063 (2)	0.078 (2)	0.0463 (18)	−0.0012 (17)	−0.0008 (15)	−0.0052 (16)
C4	0.054 (2)	0.073 (2)	0.0438 (15)	0.0052 (16)	−0.0048 (13)	−0.0029 (15)
C5	0.117 (3)	0.085 (3)	0.064 (2)	0.019 (2)	0.0199 (19)	0.023 (2)
C6	0.128 (3)	0.076 (2)	0.067 (2)	0.010 (2)	−0.022 (2)	0.013 (2)
C7	0.058 (2)	0.0618 (19)	0.0524 (16)	0.0087 (15)	−0.0061 (14)	−0.0047 (15)
C8	0.0385 (17)	0.0557 (18)	0.0481 (15)	0.0009 (14)	−0.0004 (12)	−0.0002 (13)
C9	0.060 (2)	0.151 (4)	0.080 (2)	0.010 (2)	−0.0213 (18)	−0.031 (2)
C10	0.059 (2)	0.103 (3)	0.076 (2)	0.0165 (19)	0.0071 (17)	−0.0200 (19)
C11	0.091 (2)	0.063 (2)	0.081 (2)	−0.0007 (19)	−0.0015 (18)	−0.0131 (18)
C12	0.059 (2)	0.0625 (19)	0.0496 (16)	0.0101 (15)	−0.0062 (13)	0.0010 (14)
C13	0.0500 (18)	0.063 (2)	0.0404 (15)	−0.0043 (15)	−0.0073 (12)	0.0002 (15)
C14	0.0520 (19)	0.063 (2)	0.0388 (15)	−0.0052 (15)	0.0005 (12)	−0.0016 (14)
C15	0.054 (2)	0.064 (2)	0.0535 (19)	−0.0055 (17)	0.0008 (14)	−0.0021 (16)
C16	0.100 (3)	0.077 (2)	0.073 (2)	0.005 (2)	0.0090 (19)	−0.026 (2)
C17	0.194 (5)	0.076 (3)	0.109 (3)	0.047 (3)	0.008 (3)	−0.010 (2)

O1—C3	1.202 (3)	C6—H6B	0.9700
O2—C13	1.357 (3)	C7—C8	1.537 (4)
O2—H2O	0.93 (3)	C7—H7	0.9800
O3—C14	1.394 (3)	C8—H8	0.9800
O3—C7	1.452 (3)	C9—H9A	0.9600
O4—C15	1.231 (3)	C9—H9B	0.9600
O5—C15	1.321 (3)	C9—H9C	0.9600
O5—C16	1.468 (3)	C10—H10A	0.9600
C1—C12	1.530 (3)	C10—H10B	0.9600
C1—C8	1.531 (3)	C10—H10C	0.9600
C1—C2	1.545 (3)	C11—H11A	0.9600
C1—H1	0.9800	C11—H11B	0.9600
C2—C10	1.521 (4)	C11—H11C	0.9600
C2—C3	1.522 (4)	C12—C13	1.496 (4)
C2—C11	1.553 (4)	C12—H12A	0.9700
C3—C4	1.525 (4)	C12—H12B	0.9700
C4—C9	1.526 (4)	C13—C14	1.343 (4)
C4—C8	1.545 (4)	C14—C15	1.462 (4)
C4—C5	1.550 (4)	C16—C17	1.465 (5)
C5—C6	1.479 (4)	C16—H16A	0.9700
C5—H5A	0.9700	C16—H16B	0.9700
C5—H5B	0.9700	C17—H17A	0.9600
C6—C7	1.505 (4)	C17—H17B	0.9600
C6—H6A	0.9700	C17—H17C	0.9600
C13—O2—H2O	102 (2)	C4—C8—H8	110.7
C14—O3—C7	113.1 (2)	C4—C9—H9A	109.5
C15—O5—C16	116.3 (2)	C4—C9—H9B	109.5
C12—C1—C8	112.7 (2)	H9A—C9—H9B	109.5
C12—C1—C2	116.1 (2)	C4—C9—H9C	109.5
C8—C1—C2	105.5 (2)	H9A—C9—H9C	109.5
C12—C1—H1	107.4	H9B—C9—H9C	109.5
C8—C1—H1	107.4	C2—C10—H10A	109.5
C2—C1—H1	107.4	C2—C10—H10B	109.5
C10—C2—C3	112.0 (2)	H10A—C10—H10B	109.5
C10—C2—C1	113.9 (2)	C2—C10—H10C	109.5
C3—C2—C1	101.9 (2)	H10A—C10—H10C	109.5
C10—C2—C11	110.0 (3)	H10B—C10—H10C	109.5
C3—C2—C11	105.7 (2)	C2—C11—H11A	109.5
C1—C2—C11	112.8 (2)	C2—C11—H11B	109.5
O1—C3—C2	124.6 (3)	H11A—C11—H11B	109.5
O1—C3—C4	124.6 (3)	C2—C11—H11C	109.5
C2—C3—C4	110.8 (2)	H11A—C11—H11C	109.5
C3—C4—C9	111.8 (2)	H11B—C11—H11C	109.5
C3—C4—C8	104.3 (2)	C13—C12—C1	116.0 (2)
C9—C4—C8	115.3 (2)	C13—C12—H12A	108.3
C3—C4—C5	110.8 (2)	C1—C12—H12A	108.3
C9—C4—C5	112.3 (3)	C13—C12—H12B	108.3
C8—C4—C5	101.6 (2)	C1—C12—H12B	108.3
C6—C5—C4	106.8 (3)	H12A—C12—H12B	107.4
C6—C5—H5A	110.4	C14—C13—O2	121.7 (3)
C4—C5—H5A	110.4	C14—C13—C12	127.0 (3)
C6—C5—H5B	110.4	O2—C13—C12	111.3 (3)
C4—C5—H5B	110.4	C13—C14—O3	122.2 (2)
H5A—C5—H5B	108.6	C13—C14—C15	120.8 (3)
C5—C6—C7	106.8 (3)	O3—C14—C15	117.0 (3)
C5—C6—H6A	110.4	O4—C15—O5	123.2 (3)
C7—C6—H6A	110.4	O4—C15—C14	122.9 (3)
C5—C6—H6B	110.4	O5—C15—C14	114.0 (3)
C7—C6—H6B	110.4	C17—C16—O5	107.9 (3)
H6A—C6—H6B	108.6	C17—C16—H16A	110.1
O3—C7—C6	109.2 (3)	O5—C16—H16A	110.1
O3—C7—C8	111.2 (2)	C17—C16—H16B	110.1
C6—C7—C8	107.1 (2)	O5—C16—H16B	110.1
O3—C7—H7	109.8	H16A—C16—H16B	108.4
C6—C7—H7	109.8	C16—C17—H17A	109.5
C8—C7—H7	109.8	C16—C17—H17B	109.5
C1—C8—C7	113.5 (2)	H17A—C17—H17B	109.5
C1—C8—C4	104.8 (2)	C16—C17—H17C	109.5
C7—C8—C4	106.3 (2)	H17A—C17—H17C	109.5
C1—C8—H8	110.7	H17B—C17—H17C	109.5
C7—C8—H8	110.7
C12—C1—C2—C10	79.9 (3)	C2—C1—C8—C4	35.4 (3)
C8—C1—C2—C10	−154.5 (2)	O3—C7—C8—C1	16.3 (3)
C12—C1—C2—C3	−159.2 (2)	C6—C7—C8—C1	−103.0 (3)
C8—C1—C2—C3	−33.6 (3)	O3—C7—C8—C4	131.0 (2)
C12—C1—C2—C11	−46.3 (3)	C6—C7—C8—C4	11.7 (3)
C8—C1—C2—C11	79.3 (3)	C3—C4—C8—C1	−22.2 (3)
C10—C2—C3—O1	−38.1 (4)	C9—C4—C8—C1	−145.2 (3)
C1—C2—C3—O1	−160.2 (3)	C5—C4—C8—C1	93.0 (3)
C11—C2—C3—O1	81.8 (4)	C3—C4—C8—C7	−142.7 (2)
C10—C2—C3—C4	142.1 (3)	C9—C4—C8—C7	94.4 (3)
C1—C2—C3—C4	20.0 (3)	C5—C4—C8—C7	−27.4 (3)
C11—C2—C3—C4	−98.1 (3)	C8—C1—C12—C13	49.8 (3)
O1—C3—C4—C9	−53.5 (4)	C2—C1—C12—C13	171.6 (2)
C2—C3—C4—C9	126.4 (3)	C1—C12—C13—C14	8.5 (4)
O1—C3—C4—C8	−178.7 (3)	C1—C12—C13—O2	−169.0 (2)
C2—C3—C4—C8	1.1 (3)	O2—C13—C14—O3	−177.2 (2)
O1—C3—C4—C5	72.7 (4)	C12—C13—C14—O3	5.5 (4)
C2—C3—C4—C5	−107.5 (3)	O2—C13—C14—C15	1.5 (4)
C3—C4—C5—C6	144.6 (3)	C12—C13—C14—C15	−175.8 (3)
C9—C4—C5—C6	−89.5 (3)	C7—O3—C14—C13	−75.6 (3)
C8—C4—C5—C6	34.3 (3)	C7—O3—C14—C15	105.7 (3)
C4—C5—C6—C7	−28.1 (4)	C16—O5—C15—O4	1.9 (4)
C14—O3—C7—C6	−172.9 (2)	C16—O5—C15—C14	−178.6 (2)
C14—O3—C7—C8	69.1 (3)	C13—C14—C15—O4	−6.2 (4)
C5—C6—C7—O3	−110.5 (3)	O3—C14—C15—O4	172.5 (2)
C5—C6—C7—C8	10.0 (4)	C13—C14—C15—O5	174.3 (3)
C12—C1—C8—C7	−81.4 (3)	O3—C14—C15—O5	−7.0 (4)
C2—C1—C8—C7	151.0 (2)	C15—O5—C16—C17	167.3 (3)
C12—C1—C8—C4	163.1 (2)

D—H···A	D—H	H···A	D···A	D—H···A
O2—H2O···O4	0.93 (3)	1.69 (3)	2.565 (4)	155 (3)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H2O⋯O4	0.93 (3)	1.69 (3)	2.565 (4)	155 (3)