rac-(1S,6S)-Methyl 6-methyl-2-oxobicyclo­[4.1.0]heptane-1-carboxyl­ate

The crystal structure of the title compound, C₁₀H₁₄O₃, was investigated as part of a study of the chemistry of nucleophilic 1,4-additions to highly electrophilic C=C double bonds. The cyclo­hexane ring adopts a half-chair conformation. The crystal packing is stabilized by van der Waals forces.

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.040
• wR factor = 0.109
• Data-to-parameter ratio = 19.3

checkCIF/PLATON results

No syntax errors found



Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.845     1.000
            Tmin(prime) and Tmax expected:      0.955     0.984
            RR(prime) =      0.871
            Please check that your absorption correction is appropriate.
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large .............       0.87
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.98

   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
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2001b); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

rac-(1S,6S)-methyl 6-methyl-2-oxobicyclo[4.1.0]heptane-1-carboxylate

Crystal data

C10H14O3	F(000) = 392
Mr = 182.21	Dx = 1.288 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 2274 reflections
a = 7.3651 (6) Å	θ = 2.3–28.0°
b = 7.2746 (6) Å	µ = 0.09 mm^−1
c = 17.5576 (14) Å	T = 120 K
β = 92.204 (2)°	Block, colourless
V = 940.01 (13) Å^3	0.48 × 0.30 × 0.17 mm
Z = 4

Data collection

Bruker SMART 1K CCD area-detector diffractometer	2274 independent reflections
Radiation source: normal-focus sealed tube	2035 reflections with I > 2/s(I)
Graphite monochromator	Rint = 0.021
ω scans	θmax = 28.0°, θmin = 2.3°
Absorption correction: multi-scan (SADABS; Sheldrick, 2001a)	h = −9→9
Tmin = 0.846, Tmax = 1.000	k = −9→9
12246 measured reflections	l = −23→23

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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.109	H-atom parameters constrained
S = 1.09	w = 1/[σ^2(Fo^2) + (0.0601P)^2 + 0.246P] where P = (Fo^2 + 2Fc^2)/3
2274 reflections	(Δ/σ)max < 0.001
118 parameters	Δρmax = 0.39 e Å^−3
0 restraints	Δρmin = −0.18 e Å^−3

Special details

Experimental. m.p. 321–322 K; R_f: 0.31 (Et₂O:n-pentane, 1:4); IR (film) 2928, 1732, 1693, 1437, 1354, 1243, 1216, 1111, 1077, 955, 913, 863; ¹H NMR (500 MHz, CDCl₃) δ 3.73 (s, 3H), 2.36 (dddd, J = 0.7, 2.8, 4.8, 18.0 Hz, 1H), 2.12 (ddd, J = 6.6, 12.8, 18.0 Hz, 1H), 1.98 (ddd, J = 3.7, 3.7, 13.8 Hz, 1H), 1.84 (ddd, J = 4.6, 13.1, 13.1 Hz, 1H), 1.76 (m, 1H), 1.59–1.51 (m, 3H), 1.19 (s, 3H); ¹³C NMR (125 MHz, CDCl₃) δ 203.7, 169.3, 52.4, 44.5, 36.8, 29.3, 28.6,20.8, 20.4, 17.7.

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	0.33452 (13)	0.62368 (12)	0.04948 (5)	0.0332 (2)
C1	0.29152 (14)	0.52978 (14)	0.10212 (6)	0.0210 (2)
O2	0.37054 (10)	0.53980 (11)	0.17224 (5)	0.0259 (2)
C2	0.50780 (16)	0.68162 (17)	0.18275 (8)	0.0324 (3)
H21	0.6001	0.6669	0.1445	0.049*
H22	0.5652	0.6709	0.2338	0.049*
H23	0.4508	0.8028	0.1770	0.049*
C3	0.14556 (14)	0.38533 (14)	0.09961 (5)	0.0184 (2)
C4	−0.01242 (13)	0.42938 (14)	0.14703 (6)	0.0179 (2)
O3	−0.04033 (10)	0.58827 (10)	0.16610 (4)	0.0238 (2)
C5	−0.13393 (14)	0.27593 (15)	0.17305 (7)	0.0251 (2)
H51	−0.2618	0.3145	0.1637	0.030*
H52	−0.1142	0.2615	0.2288	0.030*
C6	−0.10915 (15)	0.08771 (15)	0.13598 (7)	0.0268 (3)
H61	−0.1685	−0.0076	0.1667	0.032*
H62	−0.1685	0.0878	0.0844	0.032*
C7	0.09232 (15)	0.04143 (14)	0.13000 (6)	0.0213 (2)
H71	0.1477	0.0292	0.1820	0.026*
H72	0.1033	−0.0789	0.1043	0.026*
C8	0.19786 (14)	0.18351 (14)	0.08680 (6)	0.0197 (2)
C9	0.39779 (16)	0.14034 (16)	0.08028 (7)	0.0272 (3)
H91	0.4113	0.0208	0.0554	0.041*
H92	0.4566	0.1365	0.1313	0.041*
H93	0.4549	0.2358	0.0499	0.041*
C10	0.10513 (17)	0.28945 (16)	0.02340 (6)	0.0272 (3)
H101	−0.0230	0.2586	0.0099	0.033*
H102	0.1785	0.3253	−0.0203	0.033*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0377 (5)	0.0284 (4)	0.0343 (5)	−0.0042 (4)	0.0115 (4)	0.0099 (4)
C1	0.0199 (5)	0.0166 (5)	0.0270 (5)	0.0040 (4)	0.0065 (4)	0.0026 (4)
O2	0.0228 (4)	0.0221 (4)	0.0325 (4)	−0.0051 (3)	−0.0018 (3)	0.0047 (3)
C2	0.0222 (5)	0.0248 (6)	0.0498 (7)	−0.0050 (5)	−0.0030 (5)	0.0028 (5)
C3	0.0213 (5)	0.0157 (5)	0.0184 (5)	0.0015 (4)	0.0018 (4)	0.0017 (4)
C4	0.0171 (5)	0.0181 (5)	0.0183 (4)	0.0014 (4)	−0.0025 (3)	0.0006 (4)
O3	0.0238 (4)	0.0181 (4)	0.0296 (4)	0.0016 (3)	0.0028 (3)	−0.0024 (3)
C5	0.0195 (5)	0.0195 (5)	0.0367 (6)	−0.0009 (4)	0.0054 (4)	−0.0002 (4)
C6	0.0212 (5)	0.0195 (5)	0.0396 (6)	−0.0039 (4)	0.0000 (4)	−0.0024 (4)
C7	0.0229 (5)	0.0152 (5)	0.0258 (5)	−0.0005 (4)	0.0005 (4)	−0.0012 (4)
C8	0.0251 (5)	0.0165 (5)	0.0174 (4)	0.0024 (4)	0.0027 (4)	−0.0010 (4)
C9	0.0287 (6)	0.0220 (5)	0.0318 (6)	0.0050 (4)	0.0128 (4)	0.0022 (4)
C10	0.0400 (6)	0.0244 (5)	0.0171 (5)	0.0045 (5)	−0.0008 (4)	−0.0003 (4)

Geometric parameters (Å, º)

O1—C1	1.2015 (13)	C5—H52	0.9900
C1—O2	1.3435 (14)	C6—C7	1.5291 (15)
C1—C3	1.5027 (14)	C6—H61	0.9900
O2—C2	1.4512 (13)	C6—H62	0.9900
C2—H21	0.9800	C7—C8	1.5143 (15)
C2—H22	0.9800	C7—H71	0.9900
C2—H23	0.9800	C7—H72	0.9900
C3—C4	1.4914 (14)	C8—C10	1.4971 (15)
C3—C10	1.5281 (14)	C8—C9	1.5143 (15)
C3—C8	1.5365 (14)	C9—H91	0.9800
C4—O3	1.2230 (13)	C9—H92	0.9800
C4—C5	1.5123 (14)	C9—H93	0.9800
C5—C6	1.5300 (16)	C10—H101	0.9900
C5—H51	0.9900	C10—H102	0.9900
O1—C1—O2	123.81 (10)	C7—C6—H62	109.4
O1—C1—C3	125.77 (10)	C5—C6—H62	109.4
O2—C1—C3	110.43 (8)	H61—C6—H62	108.0
C1—O2—C2	115.48 (9)	C8—C7—C6	113.72 (9)
O2—C2—H21	109.5	C8—C7—H71	108.8
O2—C2—H22	109.5	C6—C7—H71	108.8
H21—C2—H22	109.5	C8—C7—H72	108.8
O2—C2—H23	109.5	C6—C7—H72	108.8
H21—C2—H23	109.5	H71—C7—H72	107.7
H22—C2—H23	109.5	C10—C8—C9	117.88 (9)
C4—C3—C1	113.95 (9)	C10—C8—C7	119.70 (10)
C4—C3—C10	117.19 (9)	C9—C8—C7	114.56 (9)
C1—C3—C10	117.38 (9)	C10—C8—C3	60.48 (7)
C4—C3—C8	119.49 (9)	C9—C8—C3	117.34 (9)
C1—C3—C8	119.30 (8)	C7—C8—C3	116.26 (8)
C10—C3—C8	58.48 (7)	C8—C9—H91	109.5
O3—C4—C3	119.92 (9)	C8—C9—H92	109.5
O3—C4—C5	120.48 (9)	H91—C9—H92	109.5
C3—C4—C5	119.57 (9)	C8—C9—H93	109.5
C4—C5—C6	116.77 (9)	H91—C9—H93	109.5
C4—C5—H51	108.1	H92—C9—H93	109.5
C6—C5—H51	108.1	C8—C10—C3	61.04 (7)
C4—C5—H52	108.1	C8—C10—H101	117.7
C6—C5—H52	108.1	C3—C10—H101	117.7
H51—C5—H52	107.3	C8—C10—H102	117.7
C7—C6—C5	110.99 (9)	C3—C10—H102	117.7
C7—C6—H61	109.4	H101—C10—H102	114.8
C5—C6—H61	109.4
O1—C1—O2—C2	3.52 (15)	C5—C6—C7—C8	−56.65 (13)
C3—C1—O2—C2	−176.93 (9)	C6—C7—C8—C10	−31.53 (13)
O1—C1—C3—C4	−114.23 (12)	C6—C7—C8—C9	179.96 (9)
O2—C1—C3—C4	66.23 (11)	C6—C7—C8—C3	37.91 (13)
O1—C1—C3—C10	28.26 (15)	C4—C3—C8—C10	105.60 (11)
O2—C1—C3—C10	−151.28 (9)	C1—C3—C8—C10	−105.94 (11)
O1—C1—C3—C8	95.65 (13)	C4—C3—C8—C9	−146.20 (9)
O2—C1—C3—C8	−83.89 (11)	C1—C3—C8—C9	2.26 (13)
C1—C3—C4—O3	20.08 (13)	C10—C3—C8—C9	108.20 (11)
C10—C3—C4—O3	−122.48 (11)	C4—C3—C8—C7	−5.22 (13)
C8—C3—C4—O3	170.13 (9)	C1—C3—C8—C7	143.23 (9)
C1—C3—C4—C5	−158.18 (9)	C10—C3—C8—C7	−110.83 (11)
C10—C3—C4—C5	59.25 (13)	C9—C8—C10—C3	−107.30 (10)
C8—C3—C4—C5	−8.13 (14)	C7—C8—C10—C3	105.21 (10)
O3—C4—C5—C6	170.06 (10)	C4—C3—C10—C8	−109.53 (10)
C3—C4—C5—C6	−11.69 (14)	C1—C3—C10—C8	109.20 (10)
C4—C5—C6—C7	43.31 (14)