2-Methyl-2-(trimethyl­silyl­oxy)-3,4-dihydro-2H,5H-pyrano[3,2-c][1]benzopyran-5-one

In the title compound, C₁₆H₂₀O₄Si, the coumarin moiety is essentially planar and the pyran ring adopts a half-chair conformation.

Key indicators

• Single-crystal X-ray study
• T = 288 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.053
• wR factor = 0.152
• Data-to-parameter ratio = 15.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        Si1
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          5
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C16 H20 O4 Si

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003).

2-Methyl-2-(trimethylsilyloxy)-3,4-dihydro-2H,5H-pyrano[3,2-c][1]benzopyran- 5-one

Crystal data

C16H20O4Si	F(000) = 648
Mr = 304.41	Dx = 1.284 Mg m^−3
Monoclinic, P21/c	Melting point: 425.2 K
Hall symbol: -P 2ybc	Mo Kα radiation, λ = 0.71073 Å
a = 11.960 (2) Å	Cell parameters from 25 reflections
b = 10.456 (2) Å	θ = 10–13°
c = 13.039 (3) Å	µ = 0.16 mm^−1
β = 105.09 (3)°	T = 288 K
V = 1574.4 (6) Å^3	Block, colourless
Z = 4	0.40 × 0.31 × 0.28 mm

Data collection

Enraf–Nonius CAD-4 diffractometer	1878 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.028
Graphite monochromator	θmax = 25.5°, θmin = 1.8°
ω/2θ scans	h = 0→14
Absorption correction: ψ scan (XCAD4; Harms & Wocadlo, 1995)	k = 0→12
Tmin = 0.922, Tmax = 0.956	l = −15→15
3075 measured reflections	3 standard reflections every 200 reflections
2930 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.053	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.152	H-atom parameters constrained
S = 1.00	w = 1/[σ^2(Fo^2) + (0.055P)^2 + 1.48P] where P = (Fo^2 + 2Fc^2)/3
2930 reflections	(Δ/σ)max < 0.001
190 parameters	Δρmax = 0.29 e Å^−3
0 restraints	Δρmin = −0.25 e Å^−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
Si1	0.99023 (8)	0.25482 (9)	0.80234 (8)	0.0418 (3)
O1	1.12400 (18)	0.2964 (2)	0.80622 (17)	0.0409 (6)
O2	1.25967 (18)	0.1936 (2)	0.94009 (16)	0.0392 (5)
O3	1.4455 (2)	0.0500 (2)	0.6821 (2)	0.0558 (7)
O4	1.41823 (19)	−0.0834 (2)	0.80345 (18)	0.0445 (6)
C1	0.9253 (4)	0.2283 (4)	0.6587 (3)	0.0720 (13)
H1A	0.9663	0.1611	0.6340	0.108*
H1B	0.9305	0.3056	0.6204	0.108*
H1C	0.8455	0.2046	0.6473	0.108*
C2	0.9878 (4)	0.1083 (4)	0.8812 (4)	0.0783 (14)
H2A	1.0214	0.1261	0.9550	0.118*
H2B	1.0315	0.0423	0.8581	0.118*
H2C	0.9092	0.0804	0.8712	0.118*
C3	0.9099 (3)	0.3860 (4)	0.8480 (3)	0.0605 (11)
H3A	0.9421	0.4002	0.9226	0.091*
H3B	0.8298	0.3628	0.8352	0.091*
H3C	0.9163	0.4629	0.8096	0.091*
C4	1.2246 (3)	0.3160 (3)	0.8869 (2)	0.0379 (8)
C5	1.2061 (3)	0.4012 (3)	0.9747 (3)	0.0544 (10)
H5A	1.1458	0.3661	1.0025	0.082*
H5B	1.1842	0.4852	0.9470	0.082*
H5C	1.2765	0.4063	1.0304	0.082*
C6	1.3175 (3)	0.3626 (3)	0.8370 (3)	0.0455 (9)
H6A	1.3887	0.3761	0.8918	0.055*
H6B	1.2942	0.4437	0.8017	0.055*
C7	1.3385 (3)	0.2661 (3)	0.7568 (3)	0.0467 (9)
H7A	1.2740	0.2671	0.6938	0.056*
H7B	1.4082	0.2888	0.7361	0.056*
C8	1.3515 (3)	0.1357 (3)	0.8048 (2)	0.0361 (7)
C9	1.4074 (3)	0.0370 (3)	0.7593 (3)	0.0400 (8)
C10	1.3147 (2)	0.1090 (3)	0.8924 (2)	0.0326 (7)
C11	1.3358 (2)	−0.0145 (3)	0.9437 (2)	0.0332 (7)
C12	1.3868 (3)	−0.1077 (3)	0.8960 (3)	0.0376 (8)
C13	1.4101 (3)	−0.2298 (3)	0.9389 (3)	0.0498 (9)
H13	1.4438	−0.2916	0.9051	0.060*
C14	1.3820 (3)	−0.2568 (3)	1.0320 (3)	0.0502 (9)
H14	1.3961	−0.3380	1.0616	0.060*
C15	1.3326 (3)	−0.1636 (4)	1.0826 (3)	0.0497 (9)
H15	1.3155	−0.1824	1.1466	0.060*
C16	1.3091 (3)	−0.0451 (3)	1.0390 (3)	0.0430 (8)
H16	1.2751	0.0161	1.0730	0.052*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Si1	0.0387 (5)	0.0348 (5)	0.0526 (6)	0.0010 (4)	0.0130 (4)	−0.0005 (4)
O1	0.0357 (12)	0.0465 (13)	0.0393 (13)	0.0015 (10)	0.0079 (10)	−0.0004 (11)
O2	0.0471 (13)	0.0326 (12)	0.0394 (12)	0.0104 (10)	0.0139 (10)	0.0014 (10)
O3	0.0611 (16)	0.0610 (17)	0.0525 (16)	0.0071 (13)	0.0276 (13)	0.0008 (13)
O4	0.0497 (14)	0.0365 (13)	0.0499 (14)	0.0086 (11)	0.0177 (11)	−0.0038 (11)
C1	0.058 (3)	0.066 (3)	0.077 (3)	0.002 (2)	−0.010 (2)	−0.021 (2)
C2	0.080 (3)	0.060 (3)	0.105 (4)	0.001 (2)	0.043 (3)	0.031 (3)
C3	0.052 (2)	0.055 (2)	0.078 (3)	0.0100 (19)	0.023 (2)	−0.004 (2)
C4	0.0397 (18)	0.0310 (17)	0.0375 (18)	0.0055 (14)	0.0001 (14)	−0.0003 (14)
C5	0.065 (2)	0.041 (2)	0.049 (2)	0.0146 (18)	0.0015 (18)	−0.0108 (17)
C6	0.0373 (18)	0.0320 (18)	0.063 (2)	−0.0013 (15)	0.0056 (16)	0.0037 (17)
C7	0.0442 (19)	0.044 (2)	0.058 (2)	0.0017 (16)	0.0240 (17)	0.0118 (17)
C8	0.0335 (16)	0.0324 (17)	0.0411 (18)	0.0011 (14)	0.0075 (14)	0.0026 (14)
C9	0.0359 (18)	0.044 (2)	0.0376 (19)	0.0017 (15)	0.0057 (15)	−0.0001 (15)
C10	0.0293 (16)	0.0292 (16)	0.0378 (17)	−0.0007 (13)	0.0059 (13)	−0.0051 (13)
C11	0.0285 (15)	0.0317 (16)	0.0356 (17)	−0.0004 (13)	0.0017 (13)	0.0004 (13)
C12	0.0313 (17)	0.0350 (18)	0.0438 (19)	0.0035 (14)	0.0047 (14)	0.0014 (15)
C13	0.0390 (19)	0.0350 (19)	0.072 (3)	0.0043 (15)	0.0084 (18)	0.0000 (18)
C14	0.045 (2)	0.0366 (19)	0.062 (2)	0.0009 (17)	0.0018 (18)	0.0166 (18)
C15	0.043 (2)	0.055 (2)	0.049 (2)	−0.0020 (17)	0.0090 (16)	0.0180 (18)
C16	0.0405 (18)	0.0424 (19)	0.046 (2)	0.0025 (16)	0.0113 (15)	0.0050 (16)

Geometric parameters (Å, º)

Si1—O1	1.646 (2)	C5—H5B	0.9600
Si1—C2	1.849 (4)	C5—H5C	0.9600
Si1—C1	1.852 (4)	C6—C7	1.519 (5)
Si1—C3	1.859 (4)	C6—H6A	0.9700
O1—C4	1.391 (4)	C6—H6B	0.9700
O2—C10	1.348 (3)	C7—C8	1.492 (4)
O2—C4	1.464 (4)	C7—H7A	0.9700
O3—C9	1.215 (4)	C7—H7B	0.9700
O4—C12	1.377 (4)	C8—C10	1.355 (4)
O4—C9	1.377 (4)	C8—C9	1.439 (4)
C1—H1A	0.9600	C10—C11	1.446 (4)
C1—H1B	0.9600	C11—C12	1.380 (4)
C1—H1C	0.9600	C11—C16	1.399 (4)
C2—H2A	0.9600	C12—C13	1.393 (4)
C2—H2B	0.9600	C13—C14	1.370 (5)
C2—H2C	0.9600	C13—H13	0.9300
C3—H3A	0.9600	C14—C15	1.393 (5)
C3—H3B	0.9600	C14—H14	0.9300
C3—H3C	0.9600	C15—C16	1.362 (5)
C4—C6	1.507 (5)	C15—H15	0.9300
C4—C5	1.512 (4)	C16—H16	0.9300
C5—H5A	0.9600
O1—Si1—C2	110.94 (17)	C4—C6—C7	110.8 (3)
O1—Si1—C1	102.64 (17)	C4—C6—H6A	109.5
C2—Si1—C1	112.0 (2)	C7—C6—H6A	109.5
O1—Si1—C3	111.99 (15)	C4—C6—H6B	109.5
C2—Si1—C3	110.5 (2)	C7—C6—H6B	109.5
C1—Si1—C3	108.56 (19)	H6A—C6—H6B	108.1
C4—O1—Si1	134.8 (2)	C8—C7—C6	109.6 (3)
C10—O2—C4	118.0 (2)	C8—C7—H7A	109.7
C12—O4—C9	121.2 (2)	C6—C7—H7A	109.7
Si1—C1—H1A	109.5	C8—C7—H7B	109.7
Si1—C1—H1B	109.5	C6—C7—H7B	109.7
H1A—C1—H1B	109.5	H7A—C7—H7B	108.2
Si1—C1—H1C	109.5	C10—C8—C9	119.2 (3)
H1A—C1—H1C	109.5	C10—C8—C7	121.4 (3)
H1B—C1—H1C	109.5	C9—C8—C7	119.4 (3)
Si1—C2—H2A	109.5	O3—C9—O4	115.7 (3)
Si1—C2—H2B	109.5	O3—C9—C8	125.2 (3)
H2A—C2—H2B	109.5	O4—C9—C8	119.1 (3)
Si1—C2—H2C	109.5	O2—C10—C8	124.0 (3)
H2A—C2—H2C	109.5	O2—C10—C11	114.8 (3)
H2B—C2—H2C	109.5	C8—C10—C11	121.2 (3)
Si1—C3—H3A	109.5	C12—C11—C16	118.0 (3)
Si1—C3—H3B	109.5	C12—C11—C10	117.8 (3)
H3A—C3—H3B	109.5	C16—C11—C10	124.2 (3)
Si1—C3—H3C	109.5	O4—C12—C11	121.2 (3)
H3A—C3—H3C	109.5	O4—C12—C13	116.7 (3)
H3B—C3—H3C	109.5	C11—C12—C13	122.1 (3)
O1—C4—O2	108.3 (2)	C14—C13—C12	118.3 (3)
O1—C4—C6	108.1 (3)	C14—C13—H13	120.8
O2—C4—C6	109.5 (2)	C12—C13—H13	120.8
O1—C4—C5	113.0 (3)	C13—C14—C15	120.6 (3)
O2—C4—C5	103.7 (2)	C13—C14—H14	119.7
C6—C4—C5	114.0 (3)	C15—C14—H14	119.7
C4—C5—H5A	109.5	C16—C15—C14	120.3 (3)
C4—C5—H5B	109.5	C16—C15—H15	119.8
H5A—C5—H5B	109.5	C14—C15—H15	119.8
C4—C5—H5C	109.5	C15—C16—C11	120.6 (3)
H5A—C5—H5C	109.5	C15—C16—H16	119.7
H5B—C5—H5C	109.5	C11—C16—H16	119.7
C2—Si1—O1—C4	−51.3 (3)	C4—O2—C10—C11	−173.8 (2)
C1—Si1—O1—C4	−171.1 (3)	C9—C8—C10—O2	−178.8 (3)
C3—Si1—O1—C4	72.6 (3)	C7—C8—C10—O2	3.2 (5)
Si1—O1—C4—O2	65.3 (3)	C9—C8—C10—C11	3.1 (4)
Si1—O1—C4—C6	−176.1 (2)	C7—C8—C10—C11	−174.9 (3)
Si1—O1—C4—C5	−48.9 (4)	O2—C10—C11—C12	176.9 (3)
C10—O2—C4—O1	78.8 (3)	C8—C10—C11—C12	−4.8 (4)
C10—O2—C4—C6	−38.9 (3)	O2—C10—C11—C16	−3.9 (4)
C10—O2—C4—C5	−160.9 (3)	C8—C10—C11—C16	174.4 (3)
O1—C4—C6—C7	−58.7 (3)	C9—O4—C12—C11	4.6 (4)
O2—C4—C6—C7	59.2 (3)	C9—O4—C12—C13	−174.8 (3)
C5—C4—C6—C7	174.8 (3)	C16—C11—C12—O4	−178.3 (3)
C4—C6—C7—C8	−48.1 (4)	C10—C11—C12—O4	1.0 (4)
C6—C7—C8—C10	17.7 (4)	C16—C11—C12—C13	1.1 (5)
C6—C7—C8—C9	−160.3 (3)	C10—C11—C12—C13	−179.7 (3)
C12—O4—C9—O3	174.8 (3)	O4—C12—C13—C14	178.8 (3)
C12—O4—C9—C8	−6.4 (4)	C11—C12—C13—C14	−0.6 (5)
C10—C8—C9—O3	−178.8 (3)	C12—C13—C14—C15	−0.7 (5)
C7—C8—C9—O3	−0.8 (5)	C13—C14—C15—C16	1.4 (5)
C10—C8—C9—O4	2.5 (5)	C14—C15—C16—C11	−0.9 (5)
C7—C8—C9—O4	−179.5 (3)	C12—C11—C16—C15	−0.3 (5)
C4—O2—C10—C8	8.0 (4)	C10—C11—C16—C15	−179.5 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5C···O3^i	0.96	2.47	3.426 (5)	171
C13—H13···O3^ii	0.93	2.56	3.492 (4)	175

Symmetry codes: (i) x, −y+1/2, z+1/2; (ii) −x+3, y−1/2, −z+3/2.