organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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3,5-Di­methyl-2,6-di­phenyl-3,4,5,6-tetra­hydro-2H-pyran-4-one

aDepartment of Chemistry, Government College University, Lahore 54000, Pakistan., and bApplied Chemistry Research Centre, PCSIR Laboratories Complex, Lahore 54600, Pakistan
*Correspondence e-mail: iukhan.gcu@gmail.com

(Received 13 January 2009; accepted 14 January 2009; online 4 February 2009)

The mol­ecular structure of the title compound, C19H20O2, reveals a slightly distorted chair conformation for the tetra­hydro­pyran ring with the two methyl and two phenyl substituents in equatorial positions.

Related literature

For the isolation of the title compound from its natural source and its biological activity, see: Noller (1966[Noller, C. R. (1966). A Textbook of Organic Chemistry, 3rd ed, pp. 521-522. London: W. B. Saunders.]). For conformational studies, see: Belakhov et al. (2002[Belakhov, V., Botoshansky, M. & Baasov, T. (2002). Acta Cryst. C58, m450-m452.]); Jose Kavitha et al. (2003[Jose Kavitha, S., Sarangarajan, T. R., Thanikasalam, K., Panchanatheswaran, K. & Jeyaraman, R. (2003). Acta Cryst. E59, o463-o465.]); Kumar et al. (1999[Kumar, R., Parmar, V. S. & Errington, W. (1999). Acta Cryst. C55, 561-563.]); Ray et al. (1998[Ray, S., Sarkhel, S., Maulik, P. R., Lobkovsky, E. & Clardy, J. (1998). Acta Cryst. C54, 134-136.]); Usman et al. (2002[Usman, A., Razak, I. A., Fun, H.-K., Chantrapromma, S., Zhao, B.-G. & Xu, J.-H. (2002). Acta Cryst. C58, o57-o58.]). For the synthesis of related molecules, see: Krishnamoorthy et al. (2003[Krishnamoorthy, B. S., Sarangarajan, T. R., Thanikasalam, K., Panchanatheswaran, K. & Jeyaraman, R. (2003). Acta Cryst. E59, o461-o462.]); Parthiban et al. (2003[Parthiban, P., Umamatheswari, S., Doddi, A., Ramkumar, V. & Kabilan, S. (2007). Acta Cryst. E63, o4373.]).

[Scheme 1]

Experimental

Crystal data
  • C19H20O2

  • Mr = 280.35

  • Orthorhombic, P b c a

  • a = 14.7247 (10) Å

  • b = 9.2803 (7) Å

  • c = 23.0393 (16) Å

  • V = 3148.3 (4) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 0.08 mm−1

  • T = 296 (2) K

  • 0.32 × 0.18 × 0.11 mm

Data collection
  • Bruker APEXII CCD area-detector diffractometer

  • Absorption correction: none

  • 18754 measured reflections

  • 3885 independent reflections

  • 1969 reflections with I > 2σ(I)

  • Rint = 0.083

Refinement
  • R[F2 > 2σ(F2)] = 0.050

  • wR(F2) = 0.163

  • S = 0.92

  • 3885 reflections

  • 190 parameters

  • H-atom parameters constrained

  • Δρmax = 0.25 e Å−3

  • Δρmin = −0.20 e Å−3

Data collection: APEX2 (Bruker, 2006[Bruker (2006). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2006[Bruker (2006). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]); software used to prepare material for publication: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]) and local programs.

Supporting information


Comment top

Tetrahydropyran-4-one moiety has been found in various naturally occurring biologically active heterocyclic compounds (Noller, 1966). Japp and Maitland reported the synthesis of various tetrahydropyrans (Japp & Maitland, 1904) for the first time. Since then, a large number of tetrahydropyran derivatives have been reported with different conformations for the six-membered heterocyclic ring such as sofa (Ray et al., 1998), planar (Kumar et al., 1999), chair (Belakhov et al., 2002; Krishnamoorthy et al., 2003; Jose Kavitha et al., 2003) or twist boat (Usman et al., 2002). Adoption of a particular conformation mainly depends upon the number and nature of the substituents and the level of unsaturation.

In the title compound C19H20O2,as shown in Fig. 1, the tetrahydropyran ring adopts a chair conformation with two methyl and two phenyl groups attached to it. All the methyl and phenyl groups occupy equatorial positions as was also reported for related molecules (Parthiban et al., 2003; Krishnamoorthy et al., 2003; Jose Kavitha et al., 2003). There are no strong intermolecular interactions between the molecules.

Related literature top

For the isolation from the natural source and biological activity, see: Noller (1966). For the synthesis of tetrahydropyrans, see: Japp & Maitland (1904). For conformational studies, see: Belakhov et al. (2002); Jose Kavitha et al. (2003); Kumar et al. (1999); Ray et al. (1998); Usman et al. (2002). For related literature, see: Krishnamoorthy et al. (2003); Parthiban et al. (2003).

Experimental top

An alcoholic solution of sodium hydroxide (8%; 10.0 ml) was added drop wise to a mixture of 3-pentanone (1.06 ml) and benzaldehyde (2.1 ml) while stirring. The contents were kept stirred for another six hours till the formation of precipitates at bottom which were washed with cold water and re-crystallized in acetone for X-Ray studies.

Refinement top

H atoms bound to C were placed in calculated positions (C—H distance = 0.93 to 0.98Å) using a riding model with U(H) set to 1.2 Ueq(C) or 1.5 Ueq(Cmethyl).

Computing details top

Data collection: APEX2 (Bruker, 2006); cell refinement: SAINT (Bruker, 2006); data reduction: SAINT (Bruker, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and local programs.

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing 50% probability displacement ellipsoids and the atom-numbering scheme.
3,5-Dimethyl-2,6-diphenyl-3,4,5,6-tetrahydro-2H-pyran-4-one top
Crystal data top
C19H20O2F(000) = 1200
Mr = 280.35Dx = 1.183 Mg m3
Orthorhombic, PbcaMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2abCell parameters from 1807 reflections
a = 14.7247 (10) Åθ = 2.7–21.7°
b = 9.2803 (7) ŵ = 0.08 mm1
c = 23.0393 (16) ÅT = 296 K
V = 3148.3 (4) Å3Needles, orange
Z = 80.32 × 0.18 × 0.11 mm
Data collection top
Bruker APEXII CCD area-detector
diffractometer
1969 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.083
Graphite monochromatorθmax = 28.3°, θmin = 2.2°
Detector resolution: 7.5 pixels mm-1h = 1219
ϕ and ω scansk = 1212
18754 measured reflectionsl = 3028
3885 independent reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.050Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.163H-atom parameters constrained
S = 0.92 w = 1/[σ2(Fo2) + (0.0702P)2]
where P = (Fo2 + 2Fc2)/3
3885 reflections(Δ/σ)max < 0.001
190 parametersΔρmax = 0.25 e Å3
0 restraintsΔρmin = 0.20 e Å3
Crystal data top
C19H20O2V = 3148.3 (4) Å3
Mr = 280.35Z = 8
Orthorhombic, PbcaMo Kα radiation
a = 14.7247 (10) ŵ = 0.08 mm1
b = 9.2803 (7) ÅT = 296 K
c = 23.0393 (16) Å0.32 × 0.18 × 0.11 mm
Data collection top
Bruker APEXII CCD area-detector
diffractometer
1969 reflections with I > 2σ(I)
18754 measured reflectionsRint = 0.083
3885 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0500 restraints
wR(F2) = 0.163H-atom parameters constrained
S = 0.92Δρmax = 0.25 e Å3
3885 reflectionsΔρmin = 0.20 e Å3
190 parameters
Special details top

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) top
xyzUiso*/Ueq
O10.26436 (11)0.0831 (2)0.17630 (7)0.0820 (6)
O20.49065 (9)0.29668 (16)0.21555 (6)0.0484 (4)
C10.34164 (16)0.1191 (2)0.18707 (11)0.0536 (6)
C20.37801 (14)0.1225 (2)0.24820 (9)0.0509 (6)
H20.42680.05090.25070.061*
C30.42129 (14)0.2730 (2)0.25768 (9)0.0481 (6)
H30.37410.34630.25240.058*
C40.40680 (15)0.1656 (3)0.14038 (9)0.0524 (6)
H40.45280.08970.13710.063*
C50.45719 (15)0.3048 (3)0.15765 (9)0.0493 (6)
H50.41490.38600.15490.059*
C60.46250 (14)0.2921 (2)0.31692 (9)0.0466 (6)
C70.41229 (16)0.3486 (2)0.36203 (10)0.0530 (6)
H70.35270.37730.35530.064*
C80.44825 (17)0.3634 (3)0.41681 (11)0.0622 (7)
H80.41300.40130.44660.075*
C90.53592 (18)0.3224 (3)0.42750 (11)0.0672 (7)
H90.56020.33170.46460.081*
C100.58800 (17)0.2672 (3)0.38303 (11)0.0649 (7)
H100.64790.24050.39000.078*
C110.55156 (15)0.2515 (3)0.32831 (10)0.0562 (6)
H110.58700.21330.29860.067*
C120.53684 (15)0.3335 (2)0.11866 (9)0.0464 (6)
C130.61089 (15)0.2416 (3)0.11876 (10)0.0581 (7)
H130.61200.16350.14400.070*
C140.68301 (16)0.2649 (3)0.08169 (13)0.0701 (8)
H140.73250.20260.08230.084*
C150.68223 (19)0.3787 (4)0.04411 (12)0.0749 (8)
H150.73070.39330.01890.090*
C160.6098 (2)0.4710 (3)0.04381 (11)0.0745 (8)
H160.60940.54940.01870.089*
C170.53748 (17)0.4482 (3)0.08070 (10)0.0607 (7)
H170.48840.51120.07990.073*
C180.30683 (16)0.0820 (3)0.29241 (11)0.0744 (8)
H18A0.33300.08460.33060.112*
H18B0.28500.01340.28440.112*
H18C0.25730.14900.29040.112*
C190.36211 (17)0.1792 (3)0.08100 (11)0.0801 (9)
H19A0.40680.20730.05280.120*
H19B0.31510.25070.08260.120*
H19C0.33630.08810.07010.120*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0478 (10)0.1251 (17)0.0730 (12)0.0189 (11)0.0087 (9)0.0002 (11)
O20.0483 (9)0.0578 (9)0.0389 (9)0.0037 (7)0.0026 (7)0.0010 (8)
C10.0424 (14)0.0601 (15)0.0582 (16)0.0004 (12)0.0031 (12)0.0027 (13)
C20.0448 (13)0.0581 (14)0.0500 (15)0.0028 (11)0.0009 (12)0.0031 (12)
C30.0447 (12)0.0545 (14)0.0450 (14)0.0039 (11)0.0017 (11)0.0024 (12)
C40.0433 (14)0.0677 (17)0.0462 (14)0.0014 (11)0.0047 (12)0.0027 (12)
C50.0501 (14)0.0552 (14)0.0427 (14)0.0081 (11)0.0033 (12)0.0029 (11)
C60.0443 (13)0.0492 (13)0.0463 (14)0.0017 (11)0.0014 (11)0.0033 (12)
C70.0537 (15)0.0565 (15)0.0489 (15)0.0024 (11)0.0035 (13)0.0002 (12)
C80.0755 (18)0.0663 (17)0.0447 (15)0.0013 (14)0.0069 (14)0.0003 (13)
C90.080 (2)0.0714 (18)0.0503 (16)0.0095 (15)0.0124 (16)0.0052 (14)
C100.0531 (16)0.0769 (19)0.0646 (18)0.0011 (13)0.0129 (14)0.0070 (15)
C110.0509 (14)0.0659 (16)0.0518 (15)0.0019 (12)0.0004 (13)0.0004 (13)
C120.0487 (14)0.0514 (14)0.0391 (13)0.0006 (11)0.0002 (11)0.0006 (11)
C130.0478 (14)0.0622 (16)0.0644 (17)0.0017 (12)0.0012 (13)0.0047 (13)
C140.0489 (15)0.086 (2)0.076 (2)0.0030 (14)0.0021 (15)0.0113 (18)
C150.0689 (19)0.105 (2)0.0512 (17)0.0200 (18)0.0112 (15)0.0052 (17)
C160.089 (2)0.083 (2)0.0518 (17)0.0164 (17)0.0014 (17)0.0147 (15)
C170.0705 (17)0.0613 (16)0.0502 (15)0.0059 (13)0.0026 (14)0.0067 (14)
C180.0675 (17)0.089 (2)0.0669 (18)0.0198 (15)0.0073 (15)0.0073 (15)
C190.0700 (18)0.120 (2)0.0506 (17)0.0133 (16)0.0127 (14)0.0010 (16)
Geometric parameters (Å, º) top
O1—C11.212 (2)C9—H90.9300
O2—C51.424 (2)C10—C111.378 (3)
O2—C31.426 (2)C10—H100.9300
C1—C41.504 (3)C11—H110.9300
C1—C21.507 (3)C12—C171.377 (3)
C2—C181.509 (3)C12—C131.385 (3)
C2—C31.550 (3)C13—C141.380 (3)
C2—H20.9800C13—H130.9300
C3—C61.504 (3)C14—C151.366 (4)
C3—H30.9800C14—H140.9300
C4—C191.523 (3)C15—C161.367 (4)
C4—C51.542 (3)C15—H150.9300
C4—H40.9800C16—C171.379 (3)
C5—C121.501 (3)C16—H160.9300
C5—H50.9800C17—H170.9300
C6—C71.379 (3)C18—H18A0.9600
C6—C111.389 (3)C18—H18B0.9600
C7—C81.376 (3)C18—H18C0.9600
C7—H70.9300C19—H19A0.9600
C8—C91.368 (3)C19—H19B0.9600
C8—H80.9300C19—H19C0.9600
C9—C101.378 (3)
C5—O2—C3113.45 (15)C8—C9—H9120.2
O1—C1—C4122.1 (2)C10—C9—H9120.2
O1—C1—C2122.1 (2)C11—C10—C9120.2 (2)
C4—C1—C2115.83 (18)C11—C10—H10119.9
C1—C2—C18112.26 (18)C9—C10—H10119.9
C1—C2—C3107.24 (17)C10—C11—C6120.8 (2)
C18—C2—C3114.50 (19)C10—C11—H11119.6
C1—C2—H2107.5C6—C11—H11119.6
C18—C2—H2107.5C17—C12—C13118.1 (2)
C3—C2—H2107.5C17—C12—C5121.5 (2)
O2—C3—C6108.08 (16)C13—C12—C5120.3 (2)
O2—C3—C2109.72 (17)C14—C13—C12120.6 (2)
C6—C3—C2113.57 (18)C14—C13—H13119.7
O2—C3—H3108.4C12—C13—H13119.7
C6—C3—H3108.4C15—C14—C13120.5 (2)
C2—C3—H3108.4C15—C14—H14119.8
C1—C4—C19112.98 (19)C13—C14—H14119.8
C1—C4—C5111.25 (18)C14—C15—C16119.6 (3)
C19—C4—C5111.73 (19)C14—C15—H15120.2
C1—C4—H4106.8C16—C15—H15120.2
C19—C4—H4106.8C15—C16—C17120.2 (3)
C5—C4—H4106.8C15—C16—H16119.9
O2—C5—C12107.44 (17)C17—C16—H16119.9
O2—C5—C4111.32 (18)C12—C17—C16121.0 (2)
C12—C5—C4111.73 (18)C12—C17—H17119.5
O2—C5—H5108.8C16—C17—H17119.5
C12—C5—H5108.8C2—C18—H18A109.5
C4—C5—H5108.8C2—C18—H18B109.5
C7—C6—C11117.8 (2)H18A—C18—H18B109.5
C7—C6—C3120.8 (2)C2—C18—H18C109.5
C11—C6—C3121.3 (2)H18A—C18—H18C109.5
C8—C7—C6121.5 (2)H18B—C18—H18C109.5
C8—C7—H7119.2C4—C19—H19A109.5
C6—C7—H7119.2C4—C19—H19B109.5
C9—C8—C7120.0 (2)H19A—C19—H19B109.5
C9—C8—H8120.0C4—C19—H19C109.5
C7—C8—H8120.0H19A—C19—H19C109.5
C8—C9—C10119.6 (2)H19B—C19—H19C109.5
O1—C1—C2—C182.1 (3)O2—C3—C6—C1134.7 (3)
C4—C1—C2—C18177.0 (2)C2—C3—C6—C1187.3 (3)
O1—C1—C2—C3128.7 (2)C11—C6—C7—C80.6 (3)
C4—C1—C2—C350.3 (2)C3—C6—C7—C8178.4 (2)
C5—O2—C3—C6170.35 (17)C6—C7—C8—C90.3 (4)
C5—O2—C3—C265.3 (2)C7—C8—C9—C100.4 (4)
C1—C2—C3—O257.9 (2)C8—C9—C10—C110.9 (4)
C18—C2—C3—O2176.88 (18)C9—C10—C11—C60.6 (4)
C1—C2—C3—C6178.93 (18)C7—C6—C11—C100.1 (3)
C18—C2—C3—C655.8 (3)C3—C6—C11—C10178.8 (2)
O1—C1—C4—C196.9 (3)O2—C5—C12—C17125.9 (2)
C2—C1—C4—C19172.2 (2)C4—C5—C12—C17111.7 (2)
O1—C1—C4—C5133.5 (2)O2—C5—C12—C1356.2 (3)
C2—C1—C4—C545.6 (3)C4—C5—C12—C1366.2 (3)
C3—O2—C5—C12178.60 (17)C17—C12—C13—C140.0 (3)
C3—O2—C5—C458.8 (2)C5—C12—C13—C14177.9 (2)
C1—C4—C5—O246.6 (2)C12—C13—C14—C150.3 (4)
C19—C4—C5—O2173.93 (18)C13—C14—C15—C160.8 (4)
C1—C4—C5—C12166.75 (18)C14—C15—C16—C170.9 (4)
C19—C4—C5—C1266.0 (2)C13—C12—C17—C160.0 (3)
O2—C3—C6—C7146.3 (2)C5—C12—C17—C16178.0 (2)
C2—C3—C6—C791.7 (2)C15—C16—C17—C120.5 (4)

Experimental details

Crystal data
Chemical formulaC19H20O2
Mr280.35
Crystal system, space groupOrthorhombic, Pbca
Temperature (K)296
a, b, c (Å)14.7247 (10), 9.2803 (7), 23.0393 (16)
V3)3148.3 (4)
Z8
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.32 × 0.18 × 0.11
Data collection
DiffractometerBruker APEXII CCD area-detector
diffractometer
Absorption correction
No. of measured, independent and
observed [I > 2σ(I)] reflections
18754, 3885, 1969
Rint0.083
(sin θ/λ)max1)0.667
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.050, 0.163, 0.92
No. of reflections3885
No. of parameters190
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.25, 0.20

Computer programs: APEX2 (Bruker, 2006), SAINT (Bruker, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2003), SHELXTL (Sheldrick, 2008) and local programs.

 

Acknowledgements

The authors are grateful to the Higher Education Commission of Pakistan, Islamabad, for a grant for the purchase of the diffractometer.

References

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