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Acta Crystallogr Sect E Struct Rep Online. 2008 January 1; 64(Pt 1): o287.
Published online 2007 December 18. doi:  10.1107/S1600536807066159
PMCID: PMC2915339

(+)-(1S,5R,10S)-11,11-Dimeth­yl-4-oxa­tricyclo­[8.4.0.01,5]tetra­deca­ne-3,12-dione

Abstract

The title compound, C15H22O3, was prepared via amino-acid-promoted Robinson annulation followed by tandem Pd/C-mediated hydrogenation and oxidative cyclization. This product was instrumental in determining the feasibility of a stereocontrolled hydrogenation in which the directing hydroxyl group is adjacent to the 6–7-ring network and its olefinic component. The asymmetric unit consists of a single mol­ecule with normal geometric parameters. The absolute configuration was assigned based on the known enanti­omeric prescursor. Inter­molecular C—H(...)O inter­actions link each mol­ecule with four neighboring mol­ecules.

Related literature

For related chemistry, see: Brown (1987 [triangle]); Crabtree & Davis (1986 [triangle]); Inomata et al. (2005 [triangle]), Nagamine et al. (2007 [triangle]); Peng et al. (2004 [triangle]); Stork & Kahne (1983 [triangle]). For related literature on geometry, see: Allen et al. (1987 [triangle]); Desiraju & Steiner (1999 [triangle]); Steiner & Saenger (1992 [triangle]); Taylor & Kennard (1982 [triangle]).

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Object name is e-64-0o287-scheme1.jpg

Experimental

Crystal data

  • C15H22O3
  • M r = 250.33
  • Trigonal, An external file that holds a picture, illustration, etc.
Object name is e-64-0o287-efi5.jpg
  • a = 7.6239 (10) Å
  • c = 38.064 (5) Å
  • V = 1916.0 (4) Å3
  • Z = 6
  • Mo Kα radiation
  • μ = 0.09 mm−1
  • T = 150 (2) K
  • 0.35 × 0.27 × 0.19 mm

Data collection

  • Nonius KappaCCD diffractometer
  • Absorption correction: none
  • 23396 measured reflections
  • 1130 independent reflections
  • 1023 reflections with I > 2σ(I)
  • R int = 0.038

Refinement

  • R[F 2 > 2σ(F 2)] = 0.026
  • wR(F 2) = 0.057
  • S = 1.06
  • 1130 reflections
  • 165 parameters
  • 1 restraint
  • H-atom parameters constrained
  • Δρmax = 0.11 e Å−3
  • Δρmin = −0.14 e Å−3

Data collection: COLLECT (Nonius, 1997–2000 [triangle]); cell refinement: HKL SCALEPACK (Otwinowski & Minor 1997 [triangle]); data reduction: HKL DENZO (Otwinowski & Minor 1997 [triangle]) and SCALEPACK; program(s) used to solve structure: SHELXS86 (Sheldrick, 1990 [triangle]); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997 [triangle]); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 [triangle]) and SHELXTL (Bruker, 1999 [triangle]); software used to prepare material for publication: WinGX publication routines (Farrugia, 1999 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536807066159/sq2007sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536807066159/sq2007Isup2.hkl

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

Acknowledgments

The authors thank Professor E. A. Meyers for his assistance in the preparation of the manuscript.

supplementary crystallographic information

Comment

The capability of L-amino acids to promote the enantioselective intramolecular aldolization of prochiral substrates (I) and (II) has projected the related Hajos-Parrish (III) and Wieland-Miescher ketones (IV) into favored positions as starting materials for targeted synthesis (see Fig. 1). Most notably, the selection of these particular synthons has resulted in the rather direct preparation of numerous terpenoids and steroids (Inomata et al., 2005).

More recently, the discovery has been made that comparable asymmetric Robinson annulation involving (V) and (VII) is accompanied by a striking crossover in enantioselectivity (Nagamine et al., 2007). When the 1,3-cyclohexanedione (V) is involved, the S enantiomer defined by (VI) continues to be formed predominantly. On the other hand, progression to the seven-membered triketone homolog (VII) results in the kinetically favored generation of the R product (VIII) (see Fig. 2). As a result, our desire to involve 6–7 fused bicyclic systems of type (VIII) as synthetic intermediates now mandates that each ensuing step involving the introduction of a new stereogenic center be carefully evaluated. The present report details such an example.

The hindered nature of the double bond in (IX) causes this intermediate to be unreactive to a broad range of hydrogenation conditions. However, recourse to the use of 10% palladium on carbon in methanol at 550 psi leads to saturation of the olefinic linkage with concomitant loss of the acetonide functionality. The chromatographically inseparable nature of (X) and (XI) was overcome by efficient (93% overall) two-step oxidative cyclization to generate (XII) and (XIII), the ratio of which was shown by NMR analysis to be 56:44 (see Fig. 3). Identification of the less dominant, highly-crystalline product as the trans-fused isomer (XIII) was realised by X-ray crystallography, as shown in Fig. 4. The level of production of (XIII) provides suggestive indication that hydroxyl-directed hydrogenation is unable to operate at the heightened levels customarily observed (Brown, 1987; Crabtree & Davis, 1986; Peng et al., 2004; Stork & Kahne, 1983).

The bond distances in (XIII) are in agreement with those that were selected in the critical evaluation of structures in the Cambridge data base (Allen et al., 1987). The presence of intermolecular CH—O hydrogen bonds is indicated by short H to O distances (2.58Å to 2.70 Å) between the observed O1 and O2 positions and calculated H positions (Taylor & Kennard, 1982; Steiner & Saenger, 1992; Desiraju & Steiner, 1999). Each molecule H-bonds with four adjacent molecules, as shown in Fig. 5, with contact distances and angles given in the table of hydrogen bonds.

Experimental

A suspension of (IX) (20 mg) and 10% Pd—C (2 mg) in methanol (1 ml) was pressurized to 550 psi of hydrogen gas in an autoclave and stirred for 15 h at rt. After filtration through Celite and solvent evaporation, the residue was chromatographed on silica gel to afford 11 mg of an inseparable mixture of (X) and (XI). This mixture was dissolved in THF (0.5 ml) and saturated NaHCO3 solution (0.5 ml), cooled to 0 °C, treated with NaIO4 (48 mg), and stirred in the cold for 3 h. The mixture was extracted with ethyl acetate and the combined organic layers were dried and evaporated. The residue was dissolved in benzene (1 ml), and Ag2CO3 on Celite (48 mg) was introduced. After being heated at reflux for 2 h, the mixture was filtered through a Celite pad and the filtrate was evaporated under reduced pressure. Chromatographic purification was performed on silica gel to afford (XII) as a colorless oil (5 mg) and (XIII) as colorless crystals (4 mg) displaying a melting point of 155.5–156 °C after recrystallization from ethyl acetate.

Refinement

The intensity statistics are non-centrosymmetric and the systematic absences restrict the space group possibilities to P61 or P65. The correct enantiomer was chosen based on the known chiral centers at atoms C1 and C5. For the methyl groups, the hydrogen atoms were added at calculated positions using a riding model with C—H = 0.98Å and Uiso(H)=1.5*Ueq(C). The torsion angle, which defines the orientation of the methyl group about the C—C bond, was refined. The remaining hydrogen atoms were included at calculated positions using a riding model with C—H = 0.99Å and Uiso(H)=1.2*Ueq(C).

Figures

Fig. 1.
Chemical schemes for (I), (II), (III), and (IV). Hydrogen atoms are not shown
Fig. 2.
Chemical schemes for (V), (VI), (VII), and (VIII). Hydrogen atoms are not shown
Fig. 3.
Chemical schemes for (IX), (X), (XI), (XII), and (XIII).
Fig. 4.
The molecular structure is drawn with 50% probability displacement ellipsoids for the non-hydrogen atoms. The hydrogen atoms are drawn with an artificial radius.
Fig. 5.
A portion of the intermolecular hydrogen bond network. The symmetry operations for the molecules related to the central molecule are as follows: A: y, -x + y+1, 1/6 + z; B: x-y + 1, x, z - 1/6; C: y + 1, -x + y+1, 1/6 + z; D: x-y, x - 1, z - 1/6.

Crystal data

C15H22O3Z = 6
Mr = 250.33F000 = 816
Trigonal, P65Dx = 1.302 Mg m3
Hall symbol: P 65Mo Kα radiation λ = 0.71073 Å
a = 7.6239 (10) ÅCell parameters from 2164 reflections
b = 7.6239 (10) Åθ = 2.0–25.0º
c = 38.064 (5) ŵ = 0.09 mm1
α = 90ºT = 150 (2) K
β = 90ºChunk, colorless
γ = 120º0.35 × 0.27 × 0.19 mm
V = 1916.0 (4) Å3

Data collection

Nonius KappaCCD diffractometer1023 reflections with I > 2σ(I)
Monochromator: graphiteRint = 0.038
Detector resolution: 9 pixels mm-1θmax = 25.0º
T = 150(2) Kθmin = 3.1º
ω scansh = −9→9
Absorption correction: nonek = −7→7
23396 measured reflectionsl = −44→44
1130 independent reflections

Refinement

Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.026H-atom parameters constrained
wR(F2) = 0.057  w = 1/[σ2(Fo2) + (0.0353P)2 + 0.1114P] where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max = 0.001
1130 reflectionsΔρmax = 0.11 e Å3
165 parametersΔρmin = −0.14 e Å3
1 restraintExtinction correction: none
Primary atom site location: structure-invariant direct methods

Special details

Experimental. The data collection crystal was a clear, colorless chunk, which was cut from a cluster of crystals. Initial examination of the diffraction pattern on a Nonius Kappa CCD diffractometer indicated a trigonal or hexagonal crystal system. All work was done at 150 K using an Oxford Cryosystems Cryostream Cooler. Omega scans with a frame width of 1.0 degree were used for data collection. Data integration was done with DENZO (Otwinowski & Minor, 1997) and scaling and merging of the data was done with SCALEPACK (Otwinowski & Minor, 1997).The Laue group was determined to be 6/m by XPREP (Bruker Nonius, 2003). The intensity statistics are non-centrosymmetric and the systematic absences restrict the space group possibilities to P61 or P65. The structure was solved by the direct methods procedure in SHELXS86 (Sheldrick, 1990). Full-matrix least-squares refinements based on F2 were performed in SHELXL97 (Sheldrick, 1997), as incorporated in the WinGX package (Farrugia, 1999). The correct enantiomer was chosen based on the known chiral centers at atoms C(1) and C(5).
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.

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

xyzUiso*/Ueq
C11.1237 (3)0.6294 (3)0.84987 (5)0.0200 (4)
C20.9527 (3)0.4864 (3)0.87492 (5)0.0248 (5)
H2A0.83870.51360.87380.03*
H2B0.90170.34350.86820.03*
C31.0397 (3)0.5250 (3)0.91134 (5)0.0245 (5)
C51.3134 (3)0.7149 (3)0.87446 (5)0.0236 (4)
H51.38520.63870.86880.028*
C61.4721 (3)0.9388 (3)0.87398 (6)0.0273 (5)
H6A1.50730.98160.84920.033*
H6B1.59580.9560.88560.033*
C71.4117 (3)1.0810 (3)0.89168 (6)0.0276 (5)
H7A1.35051.0230.91480.033*
H7B1.5361.21230.89610.033*
C81.2636 (3)1.1208 (3)0.87107 (5)0.0266 (5)
H8A1.33051.19370.84920.032*
H8B1.23181.21050.88510.032*
C91.0656 (3)0.9300 (3)0.86149 (5)0.0234 (5)
H9A0.96850.96970.85250.028*
H9B1.00670.84790.8830.028*
C101.0931 (3)0.7992 (3)0.83360 (5)0.0196 (4)
H101.22460.89280.82180.024*
C110.9294 (3)0.7288 (3)0.80369 (5)0.0204 (4)
C120.9724 (3)0.6034 (3)0.77757 (5)0.0207 (4)
C130.9882 (3)0.4299 (3)0.79298 (5)0.0243 (5)
H13A1.01770.35850.77420.029*
H13B0.85860.33220.80430.029*
C141.1584 (3)0.5144 (3)0.82012 (5)0.0235 (5)
H14A1.28790.60680.80820.028*
H14B1.17020.40120.83030.028*
C150.9500 (3)0.9168 (3)0.78510 (6)0.0289 (5)
H15A0.86830.87560.76360.043*
H15B1.09241.00850.77910.043*
H15C0.90240.98650.80070.043*
C160.7081 (3)0.5997 (3)0.81654 (6)0.0280 (5)
H16A0.68410.46690.82430.042*
H16B0.61530.5820.79730.042*
H16C0.68470.66850.83620.042*
O10.9541 (2)0.4526 (2)0.93853 (4)0.0347 (4)
O21.0008 (2)0.6444 (2)0.74647 (4)0.0259 (3)
O41.2389 (2)0.6617 (2)0.91052 (3)0.0268 (3)

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
C10.0192 (11)0.0211 (10)0.0205 (10)0.0106 (9)0.0003 (8)0.0024 (8)
C20.0243 (11)0.0238 (11)0.0249 (12)0.0110 (9)0.0024 (9)0.0042 (9)
C30.0293 (11)0.0244 (11)0.0253 (12)0.0176 (9)0.0048 (10)0.0057 (9)
C50.0249 (11)0.0296 (11)0.0183 (10)0.0152 (9)0.0027 (8)0.0048 (9)
C60.0189 (10)0.0322 (12)0.0288 (12)0.0113 (10)−0.0025 (9)0.0015 (9)
C70.0230 (11)0.0247 (11)0.0277 (12)0.0063 (9)−0.0020 (9)−0.0001 (9)
C80.0309 (12)0.0228 (11)0.0241 (11)0.0119 (9)−0.0014 (9)−0.0025 (9)
C90.0267 (11)0.0262 (11)0.0205 (11)0.0157 (9)0.0013 (9)0.0002 (9)
C100.0182 (10)0.0204 (10)0.0199 (10)0.0095 (8)0.0012 (8)0.0022 (8)
C110.0213 (10)0.0243 (10)0.0181 (10)0.0132 (9)0.0003 (8)0.0008 (8)
C120.0139 (9)0.0225 (11)0.0218 (11)0.0061 (9)−0.0036 (8)−0.0017 (8)
C130.0282 (11)0.0238 (11)0.0230 (11)0.0145 (9)0.0017 (9)−0.0030 (9)
C140.0266 (11)0.0232 (10)0.0247 (11)0.0155 (9)0.0024 (9)0.0037 (9)
C150.0376 (13)0.0335 (11)0.0235 (11)0.0236 (10)−0.0037 (9)−0.0009 (9)
C160.0211 (11)0.0372 (12)0.0261 (12)0.0149 (9)−0.0028 (9)−0.0034 (9)
O10.0416 (9)0.0421 (9)0.0235 (9)0.0231 (8)0.0099 (7)0.0100 (7)
O20.0265 (8)0.0292 (8)0.0196 (8)0.0120 (7)−0.0007 (6)−0.0011 (6)
O40.0269 (8)0.0324 (8)0.0193 (7)0.0135 (7)0.0000 (6)0.0046 (6)

Geometric parameters (Å, °)

C1—C141.534 (3)C9—C101.541 (3)
C1—C21.542 (3)C9—H9A0.99
C1—C101.554 (3)C9—H9B0.99
C1—C51.565 (3)C10—C111.573 (3)
C2—C31.501 (3)C10—H101
C2—H2A0.99C11—C121.524 (3)
C2—H2B0.99C11—C151.534 (3)
C3—O11.201 (2)C11—C161.547 (3)
C3—O41.345 (2)C12—O21.216 (2)
C5—O41.463 (2)C12—C131.505 (3)
C5—C61.521 (3)C13—C141.527 (3)
C5—H51C13—H13A0.99
C6—C71.530 (3)C13—H13B0.99
C6—H6A0.99C14—H14A0.99
C6—H6B0.99C14—H14B0.99
C7—C81.524 (3)C15—H15A0.98
C7—H7A0.99C15—H15B0.98
C7—H7B0.99C15—H15C0.98
C8—C91.527 (3)C16—H16A0.98
C8—H8A0.99C16—H16B0.98
C8—H8B0.99C16—H16C0.98
C14—C1—C2112.26 (16)C10—C9—H9B109
C14—C1—C10108.82 (16)H9A—C9—H9B107.8
C2—C1—C10114.16 (16)C9—C10—C1112.96 (15)
C14—C1—C5106.98 (16)C9—C10—C11112.20 (15)
C2—C1—C5101.73 (15)C1—C10—C11115.38 (15)
C10—C1—C5112.57 (16)C9—C10—H10105
C3—C2—C1107.32 (16)C1—C10—H10105
C3—C2—H2A110.3C11—C10—H10105
C1—C2—H2A110.3C12—C11—C15109.38 (15)
C3—C2—H2B110.3C12—C11—C16108.37 (16)
C1—C2—H2B110.3C15—C11—C16108.06 (16)
H2A—C2—H2B108.5C12—C11—C10107.64 (14)
O1—C3—O4121.31 (18)C15—C11—C10108.80 (15)
O1—C3—C2128.34 (18)C16—C11—C10114.52 (16)
O4—C3—C2110.34 (16)O2—C12—C13121.53 (18)
O4—C5—C6107.62 (16)O2—C12—C11122.68 (17)
O4—C5—C1107.19 (15)C13—C12—C11115.72 (16)
C6—C5—C1120.72 (16)C12—C13—C14108.53 (16)
O4—C5—H5106.9C12—C13—H13A110
C6—C5—H5106.9C14—C13—H13A110
C1—C5—H5106.9C12—C13—H13B110
C5—C6—C7115.98 (17)C14—C13—H13B110
C5—C6—H6A108.3H13A—C13—H13B108.4
C7—C6—H6A108.3C13—C14—C1112.81 (15)
C5—C6—H6B108.3C13—C14—H14A109
C7—C6—H6B108.3C1—C14—H14A109
H6A—C6—H6B107.4C13—C14—H14B109
C8—C7—C6115.44 (17)C1—C14—H14B109
C8—C7—H7A108.4H14A—C14—H14B107.8
C6—C7—H7A108.4C11—C15—H15A109.5
C8—C7—H7B108.4C11—C15—H15B109.5
C6—C7—H7B108.4H15A—C15—H15B109.5
H7A—C7—H7B107.5C11—C15—H15C109.5
C7—C8—C9114.27 (17)H15A—C15—H15C109.5
C7—C8—H8A108.7H15B—C15—H15C109.5
C9—C8—H8A108.7C11—C16—H16A109.5
C7—C8—H8B108.7C11—C16—H16B109.5
C9—C8—H8B108.7H16A—C16—H16B109.5
H8A—C8—H8B107.6C11—C16—H16C109.5
C8—C9—C10113.03 (17)H16A—C16—H16C109.5
C8—C9—H9A109H16B—C16—H16C109.5
C10—C9—H9A109C3—O4—C5111.59 (15)
C8—C9—H9B109
C14—C1—C2—C3124.11 (17)C5—C1—C10—C11169.82 (15)
C10—C1—C2—C3−111.44 (18)C9—C10—C11—C12179.42 (16)
C5—C1—C2—C310.1 (2)C1—C10—C11—C12−49.3 (2)
C1—C2—C3—O1175.8 (2)C9—C10—C11—C1561.0 (2)
C1—C2—C3—O4−3.3 (2)C1—C10—C11—C15−167.71 (16)
C14—C1—C5—O4−131.22 (17)C9—C10—C11—C16−60.0 (2)
C2—C1—C5—O4−13.32 (19)C1—C10—C11—C1671.3 (2)
C10—C1—C5—O4109.29 (17)C15—C11—C12—O2−5.6 (2)
C14—C1—C5—C6105.2 (2)C16—C11—C12—O2112.0 (2)
C2—C1—C5—C6−136.86 (18)C10—C11—C12—O2−123.67 (19)
C10—C1—C5—C6−14.2 (3)C15—C11—C12—C13171.40 (17)
O4—C5—C6—C7−49.0 (2)C16—C11—C12—C13−71.0 (2)
C1—C5—C6—C774.4 (2)C10—C11—C12—C1353.3 (2)
C5—C6—C7—C8−74.9 (2)O2—C12—C13—C14118.03 (19)
C6—C7—C8—C956.7 (2)C11—C12—C13—C14−59.0 (2)
C7—C8—C9—C10−69.9 (2)C12—C13—C14—C159.0 (2)
C8—C9—C10—C193.9 (2)C2—C1—C14—C1371.8 (2)
C8—C9—C10—C11−133.64 (17)C10—C1—C14—C13−55.6 (2)
C14—C1—C10—C9−177.66 (16)C5—C1—C14—C13−177.43 (16)
C2—C1—C10—C956.1 (2)O1—C3—O4—C5174.92 (18)
C5—C1—C10—C9−59.3 (2)C2—C3—O4—C5−5.8 (2)
C14—C1—C10—C1151.4 (2)C6—C5—O4—C3143.75 (16)
C2—C1—C10—C11−74.9 (2)C1—C5—O4—C312.5 (2)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
C10—H10···O1i12.703.596 (2)149
C14—H14A···O1i0.992.703.562 (3)146
C2—H2A···O2ii0.992.623.449 (2)141
C9—H9B···O2ii0.992.663.454 (2)138
C5—H5···O2iii12.583.194 (2)119

Symmetry codes: (i) xy+1, x, z−1/6; (ii) y, −x+y+1, z+1/6; (iii) y+1, −x+y+1, z+1/6.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SQ2007).

References

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