4-Isopropyl-2-(4-methoxy­benzyl­idene)-3,4-dihydro­naphthalen-1(2H)-one

The title compound, C₂₁H₂₂O₂, has the exocyclic C=C double bond in an E configuration. The isopropyl group is attached in an axial position to the cyclo­hexenone ring.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C)= 0.002 Å
• R factor = 0.038
• wR factor = 0.105
• Data-to-parameter ratio = 15.0

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S1. Comment

Knowledge of the configuration and conformation of the title compound, (I), is necessary to understand its behaviour in dipolar-1,3 cycloaddition reactions (Badri et al., 1999; Bennani et al., 2002). To confirm the E configuration of the acyclic C═C double bond and the axial position of the isopropyl group an X-ray structure determination was carried out.

A perspective view of the title compound is shown in Fig. 1. Bond lengths and angles can be regarded as normal (Cambridge Crystallographic Database, Version 1.7; Mogul Version 1.0.1; Allen, 2002). The acyclic C═C double bond shows an E configuration. The carbonyl group is almost coplanar with this double bond [O1—C1—C2—C11 = − 4.61 (18)°], but the phenyl ring attached to it is twisted out of the plane of the double bond [C2—C11—C12—C17 − 35.39 (19)°]. The isopropyl group is attached in an axial position to the cyclohexenone ring.

S2. Experimental

The synthesis of 4-isopropyl-para-anisyl-phenylidene-2 tetralone-1 was achieved using the method reported by Kerbal et al. (1988). That means a condensation of para-anisaldahyde with 4-isopropyl-tetralone-1 in an alcaline medium in methanol.

S3. Refinement

All H atoms were located in a difference map and were refined with fixed individual displacement parameters [U_iso(H) = 1.2U_eq(C) or U_iso(H) = 1.5U_eq(C_methyl)] using a riding model, with C—H ranging from 0.95 to 1.00 Å. In addition, the CH₃ group attached to the O atom was allowed to rotate but not to tip.

Computing details

Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA; data reduction: X-AREA; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 1991); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2003).

Figures

Fig. 1. Perspective view of the title compound with the atom numbering; displacement ellipsoids are at the 50% probability level.

4-Isopropyl-2-(4-methoxybenzylidene)-3,4-dihydronaphthalen-1(2H)-one

Crystal data

C21H22O2	F(000) = 656
Mr = 306.39	Dx = 1.215 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 25892 reflections
a = 7.9380 (5) Å	θ = 3.4–25.8°
b = 9.3745 (4) Å	µ = 0.08 mm^−1
c = 22.7340 (16) Å	T = 173 K
β = 98.219 (5)°	Block, colourless
V = 1674.37 (17) Å^3	0.35 × 0.33 × 0.29 mm
Z = 4

Data collection

Stoe IPDS-II two-circle diffractometer	2800 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.040
Graphite monochromator	θmax = 25.6°, θmin = 3.4°
ω scans	h = −9→9
26652 measured reflections	k = −11→11
3147 independent reflections	l = −27→25

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.038	H-atom parameters constrained
wR(F^2) = 0.105	w = 1/[σ^2(Fo^2) + (0.0595P)^2 + 0.4741P] where P = (Fo^2 + 2Fc^2)/3
S = 1.02	(Δ/σ)max = 0.001
3147 reflections	Δρmax = 0.25 e Å^−3
210 parameters	Δρmin = −0.17 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.024 (3)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.97679 (11)	0.54685 (11)	0.20869 (4)	0.0364 (3)
C1	0.82768 (14)	0.58779 (12)	0.20260 (6)	0.0249 (3)
C2	0.73578 (15)	0.61684 (12)	0.25442 (5)	0.0235 (3)
C3	0.55489 (15)	0.67181 (13)	0.23986 (5)	0.0248 (3)
H3A	0.5567	0.7748	0.2303	0.030*
H3B	0.4947	0.6597	0.2748	0.030*
C4	0.45933 (14)	0.58946 (13)	0.18629 (5)	0.0231 (3)
H4	0.3423	0.6305	0.1769	0.028*
C5	0.55189 (15)	0.61442 (12)	0.13337 (5)	0.0226 (3)
C6	0.46723 (16)	0.63647 (13)	0.07599 (6)	0.0271 (3)
H6	0.3463	0.6376	0.0692	0.033*
C7	0.55750 (18)	0.65682 (13)	0.02842 (6)	0.0302 (3)
H7	0.4979	0.6728	−0.0103	0.036*
C8	0.73464 (18)	0.65375 (14)	0.03742 (6)	0.0319 (3)
H8	0.7959	0.6672	0.0049	0.038*
C9	0.82135 (16)	0.63094 (13)	0.09404 (6)	0.0287 (3)
H9	0.9422	0.6284	0.1002	0.034*
C10	0.73164 (15)	0.61173 (12)	0.14208 (5)	0.0235 (3)
C11	0.81825 (15)	0.58691 (12)	0.30893 (6)	0.0247 (3)
H11	0.9270	0.5440	0.3099	0.030*
C12	0.76367 (15)	0.61130 (12)	0.36725 (5)	0.0241 (3)
C13	0.81472 (15)	0.51513 (13)	0.41354 (6)	0.0280 (3)
H13	0.8830	0.4356	0.4062	0.034*
C14	0.76859 (16)	0.53246 (13)	0.46977 (6)	0.0287 (3)
H14	0.8035	0.4650	0.5003	0.034*
C15	0.67039 (15)	0.65011 (13)	0.48102 (5)	0.0254 (3)
C16	0.62228 (15)	0.75000 (13)	0.43603 (6)	0.0268 (3)
H16	0.5585	0.8317	0.4440	0.032*
C17	0.66704 (15)	0.73050 (13)	0.37999 (5)	0.0258 (3)
H17	0.6322	0.7984	0.3497	0.031*
O2	0.61530 (11)	0.67818 (11)	0.53422 (4)	0.0336 (2)
C18	0.66685 (19)	0.58251 (17)	0.58261 (6)	0.0397 (3)
H18A	0.6272	0.4859	0.5714	0.060*
H18B	0.6173	0.6135	0.6176	0.060*
H18C	0.7913	0.5826	0.5919	0.060*
C41	0.44219 (15)	0.42722 (13)	0.19868 (6)	0.0260 (3)
H41	0.5581	0.3838	0.2012	0.031*
C42	0.37636 (18)	0.39845 (17)	0.25752 (6)	0.0372 (3)
H42A	0.4503	0.4461	0.2899	0.056*
H42B	0.3765	0.2955	0.2650	0.056*
H42C	0.2602	0.4353	0.2555	0.056*
C43	0.32687 (19)	0.35340 (16)	0.14796 (7)	0.0390 (3)
H43A	0.3693	0.3723	0.1103	0.059*
H43B	0.2107	0.3903	0.1459	0.059*
H43C	0.3269	0.2503	0.1552	0.059*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0234 (5)	0.0488 (6)	0.0371 (5)	0.0083 (4)	0.0043 (4)	−0.0031 (4)
C1	0.0223 (6)	0.0208 (6)	0.0316 (7)	−0.0002 (4)	0.0042 (5)	−0.0022 (5)
C2	0.0233 (6)	0.0198 (6)	0.0271 (6)	−0.0004 (4)	0.0023 (5)	−0.0023 (4)
C3	0.0256 (6)	0.0248 (6)	0.0239 (6)	0.0052 (5)	0.0037 (5)	−0.0009 (5)
C4	0.0195 (5)	0.0251 (6)	0.0244 (6)	0.0049 (4)	0.0021 (4)	0.0011 (5)
C5	0.0277 (6)	0.0155 (5)	0.0249 (6)	0.0023 (4)	0.0049 (5)	−0.0007 (4)
C6	0.0306 (6)	0.0220 (6)	0.0281 (6)	0.0027 (5)	0.0019 (5)	−0.0007 (5)
C7	0.0446 (7)	0.0224 (6)	0.0231 (6)	0.0015 (5)	0.0028 (5)	−0.0002 (5)
C8	0.0455 (8)	0.0253 (6)	0.0279 (6)	−0.0010 (5)	0.0153 (6)	−0.0007 (5)
C9	0.0303 (6)	0.0233 (6)	0.0341 (7)	−0.0006 (5)	0.0107 (5)	−0.0013 (5)
C10	0.0271 (6)	0.0168 (5)	0.0272 (6)	0.0012 (4)	0.0058 (5)	−0.0009 (4)
C11	0.0222 (5)	0.0207 (6)	0.0305 (6)	0.0004 (4)	0.0014 (5)	−0.0015 (5)
C12	0.0230 (5)	0.0214 (6)	0.0262 (6)	−0.0020 (4)	−0.0021 (4)	−0.0012 (5)
C13	0.0272 (6)	0.0243 (6)	0.0307 (6)	0.0037 (5)	−0.0027 (5)	−0.0002 (5)
C14	0.0306 (6)	0.0260 (6)	0.0273 (6)	−0.0004 (5)	−0.0035 (5)	0.0052 (5)
C15	0.0236 (6)	0.0277 (6)	0.0240 (6)	−0.0065 (5)	0.0001 (4)	−0.0009 (5)
C16	0.0279 (6)	0.0221 (6)	0.0299 (6)	0.0012 (5)	0.0020 (5)	−0.0020 (5)
C17	0.0296 (6)	0.0202 (6)	0.0261 (6)	−0.0001 (5)	−0.0008 (5)	0.0024 (5)
O2	0.0359 (5)	0.0407 (5)	0.0247 (5)	−0.0007 (4)	0.0059 (4)	0.0022 (4)
C18	0.0422 (8)	0.0494 (9)	0.0270 (7)	−0.0083 (6)	0.0031 (6)	0.0083 (6)
C41	0.0201 (5)	0.0265 (6)	0.0314 (7)	0.0007 (5)	0.0038 (5)	0.0036 (5)
C42	0.0340 (7)	0.0434 (8)	0.0344 (7)	−0.0036 (6)	0.0061 (6)	0.0118 (6)
C43	0.0405 (8)	0.0357 (7)	0.0400 (8)	−0.0106 (6)	0.0031 (6)	−0.0013 (6)

Geometric parameters (Å, º)

O1—C1	1.2332 (15)	C12—C17	1.4087 (17)
C1—C10	1.4915 (17)	C13—C14	1.3887 (18)
C1—C2	1.4967 (17)	C13—H13	0.9500
C2—C11	1.3458 (17)	C14—C15	1.3951 (18)
C2—C3	1.5169 (16)	C14—H14	0.9500
C3—C4	1.5461 (16)	C15—O2	1.3691 (15)
C3—H3A	0.9900	C15—C16	1.3988 (17)
C3—H3B	0.9900	C16—C17	1.3829 (18)
C4—C5	1.5147 (16)	C16—H16	0.9500
C4—C41	1.5563 (16)	C17—H17	0.9500
C4—H4	1.0000	O2—C18	1.4331 (17)
C5—C6	1.3949 (17)	C18—H18A	0.9800
C5—C10	1.4124 (17)	C18—H18B	0.9800
C6—C7	1.3931 (18)	C18—H18C	0.9800
C6—H6	0.9500	C41—C42	1.5281 (17)
C7—C8	1.3920 (19)	C41—C43	1.5311 (18)
C7—H7	0.9500	C41—H41	1.0000
C8—C9	1.3868 (19)	C42—H42A	0.9800
C8—H8	0.9500	C42—H42B	0.9800
C9—C10	1.3980 (17)	C42—H42C	0.9800
C9—H9	0.9500	C43—H43A	0.9800
C11—C12	1.4703 (17)	C43—H43B	0.9800
C11—H11	0.9500	C43—H43C	0.9800
C12—C13	1.4009 (17)
O1—C1—C10	120.42 (11)	C17—C12—C11	123.23 (11)
O1—C1—C2	122.43 (11)	C14—C13—C12	122.02 (11)
C10—C1—C2	117.15 (10)	C14—C13—H13	119.0
C11—C2—C1	117.34 (10)	C12—C13—H13	119.0
C11—C2—C3	126.33 (11)	C13—C14—C15	119.27 (11)
C1—C2—C3	116.28 (10)	C13—C14—H14	120.4
C2—C3—C4	110.17 (9)	C15—C14—H14	120.4
C2—C3—H3A	109.6	O2—C15—C14	124.83 (11)
C4—C3—H3A	109.6	O2—C15—C16	115.39 (11)
C2—C3—H3B	109.6	C14—C15—C16	119.77 (11)
C4—C3—H3B	109.6	C17—C16—C15	120.39 (11)
H3A—C3—H3B	108.1	C17—C16—H16	119.8
C5—C4—C3	108.02 (9)	C15—C16—H16	119.8
C5—C4—C41	111.08 (9)	C16—C17—C12	120.89 (11)
C3—C4—C41	113.03 (10)	C16—C17—H17	119.6
C5—C4—H4	108.2	C12—C17—H17	119.6
C3—C4—H4	108.2	C15—O2—C18	117.76 (11)
C41—C4—H4	108.2	O2—C18—H18A	109.5
C6—C5—C10	118.40 (11)	O2—C18—H18B	109.5
C6—C5—C4	122.83 (11)	H18A—C18—H18B	109.5
C10—C5—C4	118.75 (10)	O2—C18—H18C	109.5
C7—C6—C5	120.92 (12)	H18A—C18—H18C	109.5
C7—C6—H6	119.5	H18B—C18—H18C	109.5
C5—C6—H6	119.5	C42—C41—C43	109.69 (11)
C8—C7—C6	120.26 (12)	C42—C41—C4	112.37 (11)
C8—C7—H7	119.9	C43—C41—C4	111.33 (10)
C6—C7—H7	119.9	C42—C41—H41	107.8
C9—C8—C7	119.77 (12)	C43—C41—H41	107.8
C9—C8—H8	120.1	C4—C41—H41	107.8
C7—C8—H8	120.1	C41—C42—H42A	109.5
C8—C9—C10	120.28 (12)	C41—C42—H42B	109.5
C8—C9—H9	119.9	H42A—C42—H42B	109.5
C10—C9—H9	119.9	C41—C42—H42C	109.5
C9—C10—C5	120.36 (11)	H42A—C42—H42C	109.5
C9—C10—C1	119.32 (11)	H42B—C42—H42C	109.5
C5—C10—C1	120.32 (11)	C41—C43—H43A	109.5
C2—C11—C12	129.10 (11)	C41—C43—H43B	109.5
C2—C11—H11	115.5	H43A—C43—H43B	109.5
C12—C11—H11	115.5	C41—C43—H43C	109.5
C13—C12—C17	117.62 (11)	H43A—C43—H43C	109.5
C13—C12—C11	119.10 (11)	H43B—C43—H43C	109.5
O1—C1—C2—C11	−4.61 (18)	C2—C1—C10—C9	159.78 (11)
C10—C1—C2—C11	175.95 (10)	O1—C1—C10—C5	160.09 (11)
O1—C1—C2—C3	177.82 (11)	C2—C1—C10—C5	−20.46 (15)
C10—C1—C2—C3	−1.62 (15)	C1—C2—C11—C12	176.42 (11)
C11—C2—C3—C4	−135.17 (12)	C3—C2—C11—C12	−6.3 (2)
C1—C2—C3—C4	42.14 (14)	C2—C11—C12—C13	147.14 (13)
C2—C3—C4—C5	−61.03 (12)	C2—C11—C12—C17	−35.39 (19)
C2—C3—C4—C41	62.28 (13)	C17—C12—C13—C14	1.95 (18)
C3—C4—C5—C6	−139.93 (11)	C11—C12—C13—C14	179.56 (11)
C41—C4—C5—C6	95.58 (13)	C12—C13—C14—C15	−0.91 (18)
C3—C4—C5—C10	41.72 (13)	C13—C14—C15—O2	179.24 (11)
C41—C4—C5—C10	−82.76 (12)	C13—C14—C15—C16	−1.09 (18)
C10—C5—C6—C7	−0.64 (17)	O2—C15—C16—C17	−178.30 (10)
C4—C5—C6—C7	−178.99 (11)	C14—C15—C16—C17	2.00 (18)
C5—C6—C7—C8	0.76 (18)	C15—C16—C17—C12	−0.92 (18)
C6—C7—C8—C9	−0.28 (18)	C13—C12—C17—C16	−1.02 (17)
C7—C8—C9—C10	−0.30 (19)	C11—C12—C17—C16	−178.53 (11)
C8—C9—C10—C5	0.41 (18)	C14—C15—O2—C18	2.22 (17)
C8—C9—C10—C1	−179.82 (11)	C16—C15—O2—C18	−177.46 (11)
C6—C5—C10—C9	0.05 (16)	C5—C4—C41—C42	170.49 (10)
C4—C5—C10—C9	178.47 (10)	C3—C4—C41—C42	48.88 (13)
C6—C5—C10—C1	−179.71 (10)	C5—C4—C41—C43	−66.01 (13)
C4—C5—C10—C1	−1.29 (16)	C3—C4—C41—C43	172.38 (10)
O1—C1—C10—C9	−19.67 (17)