16-Cyano-13α-(5-methyl-1,3,4-oxadiazol-2-yl)-13,16-seco-17-norandrost-4-en-3-one

In the title compound, a seco steroid derivative, C₂₁H₂₇N₃O₂, the cyclo­hexane rings of the steroid nucleus are in chair conformations, while the cyclo­hexene ring adopts a 1α-sofa conformation. In the crystal structure, inter­molecular C—H...N inter­actions link the mol­ecules into extended chains, parallel to the c axis, with graph-set motif C(5). The structure is further stabilized by weak inter­molecular C—H...O inter­actions which can be described as C(4) chains running parallel to the b axis.

Key indicators

• Single-crystal X-ray study
• T = 273 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.059
• wR factor = 0.160
• Data-to-parameter ratio = 7.7

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) .....       7.66
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for        C25
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          5
PLAT710_ALERT_4_C Delete 1-2-3 or 2-3-4 Linear Torsion Angle ... #         50
            C14 -C15 -C16 -N17    18.00  0.00   1.555   1.555   1.555   1.555

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           25.00
           From the CIF: _reflns_number_total               1823
           Count of symmetry unique reflns         1824
           Completeness (_total/calc)             99.95%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   1 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
   2 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion

---

Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997), PLATON (Spek, 2003) and Qmol (Gans & Shalloway, 2001); software used to prepare material for publication: SHELXL97 and PARST (Nardelli, 1995).

16-Cyano-13α-(5-methyl-1,3,4-oxadiazol-2-yl)-13,16-seco-17-nor- androst-4-en-3-one

Crystal data

C21H27N3O2	F(000) = 380
Mr = 353.46	Dx = 1.226 Mg m^−3
Monoclinic, P21	Melting point = 453–457 K
Hall symbol: P 2yb	Mo Kα radiation, λ = 0.71073 Å
a = 6.0831 (11) Å	Cell parameters from 3439 reflections
b = 7.6736 (14) Å	θ = 2.8–25.1°
c = 20.614 (4) Å	µ = 0.08 mm^−1
β = 95.796 (3)°	T = 273 K
V = 957.3 (3) Å^3	Needle, colourless
Z = 2	0.19 × 0.11 × 0.09 mm

Data collection

Bruker SMART CCD area-detector diffractometer	1650 reflections with I > 2s(I)
Radiation source: fine-focus sealed tube	Rint = 0.039
Graphite monochromator	θmax = 25.0°, θmin = 1.0°
ω scans	h = −7→7
9075 measured reflections	k = −9→9
1823 independent reflections	l = −24→24

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)] = 0.059	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.160	H-atom parameters constrained
S = 1.23	w = 1/[σ^2(Fo^2) + (0.1021P)^2 + 0.0266P] where P = (Fo^2 + 2Fc^2)/3
1823 reflections	(Δ/σ)max < 0.001
238 parameters	Δρmax = 0.31 e Å^−3
1 restraint	Δρmin = −0.18 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
C1	0.8008 (7)	1.1165 (5)	0.37185 (19)	0.0561 (10)
H1A	0.8734	1.2178	0.3556	0.067*
H1B	0.6540	1.1094	0.3487	0.067*
C2	0.7792 (8)	1.1418 (6)	0.4450 (2)	0.0673 (12)
H2A	0.9228	1.1707	0.4672	0.081*
H2B	0.6804	1.2386	0.4507	0.081*
C3	0.6933 (6)	0.9832 (6)	0.47488 (17)	0.0567 (10)
C4	0.7319 (6)	0.8175 (6)	0.44480 (17)	0.0548 (10)
H4	0.6730	0.7179	0.4621	0.066*
C5	0.8484 (6)	0.7992 (5)	0.39307 (15)	0.0478 (9)
C6	0.9155 (10)	0.6211 (6)	0.37250 (19)	0.0674 (12)
H6A	0.8354	0.5341	0.3949	0.081*
H6B	1.0720	0.6047	0.3853	0.081*
C7	0.8696 (9)	0.5945 (5)	0.2993 (2)	0.0622 (11)
H7A	0.7112	0.5937	0.2874	0.075*
H7B	0.9277	0.4824	0.2876	0.075*
C8	0.9750 (6)	0.7386 (4)	0.26113 (16)	0.0426 (8)
H8	1.1355	0.7340	0.2719	0.051*
C9	0.8926 (6)	0.9172 (4)	0.28192 (16)	0.0406 (8)
H9	0.7320	0.9162	0.2711	0.049*
C10	0.9316 (6)	0.9522 (5)	0.35668 (17)	0.0448 (8)
C11	0.9804 (8)	1.0629 (5)	0.24105 (18)	0.0563 (10)
H11A	0.9173	1.1731	0.2529	0.068*
H11B	1.1395	1.0706	0.2506	0.068*
C12	0.9245 (8)	1.0322 (5)	0.16844 (19)	0.0559 (10)
H12A	0.9847	1.1268	0.1445	0.067*
H12B	0.7652	1.0333	0.1585	0.067*
C13	1.0159 (6)	0.8584 (5)	0.14572 (16)	0.0466 (9)
C14	0.9244 (6)	0.7108 (4)	0.18706 (17)	0.0423 (8)
H14	0.7632	0.7166	0.1783	0.051*
C15	0.9903 (7)	0.5265 (5)	0.16560 (19)	0.0508 (9)
H15A	0.8821	0.4441	0.1787	0.061*
H15B	0.9819	0.5243	0.1184	0.061*
C16	1.2090 (8)	0.4668 (6)	0.1914 (2)	0.0608 (10)
N17	1.3790 (8)	0.4163 (6)	0.2108 (2)	0.0865 (13)
C18	1.2701 (6)	0.8622 (7)	0.1507 (2)	0.0638 (11)
H18A	1.3228	0.7613	0.1295	0.096*
H18B	1.3282	0.8621	0.1958	0.096*
H18C	1.3180	0.9656	0.1300	0.096*
C19	1.1784 (7)	0.9778 (9)	0.3788 (2)	0.0742 (14)
H19A	1.2000	0.9821	0.4256	0.111*
H19B	1.2283	1.0849	0.3612	0.111*
H19C	1.2611	0.8822	0.3635	0.111*
O20	0.6028 (6)	0.9903 (6)	0.52521 (15)	0.0819 (10)
O21	0.7221 (4)	0.8721 (4)	0.05448 (11)	0.0596 (8)
C22	0.9343 (6)	0.8317 (5)	0.07522 (16)	0.0466 (8)
N23	1.0350 (6)	0.7708 (7)	0.02923 (16)	0.0706 (11)
N24	0.8815 (7)	0.7723 (6)	−0.02733 (15)	0.0706 (11)
C25	0.7051 (7)	0.8309 (6)	−0.00959 (17)	0.0592 (10)
C26	0.4919 (9)	0.8638 (11)	−0.0487 (2)	0.095 (2)
H26A	0.4956	0.8150	−0.0915	0.142*
H26B	0.4668	0.9871	−0.0522	0.142*
H26C	0.3747	0.8106	−0.0278	0.142*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.074 (3)	0.043 (2)	0.054 (2)	−0.0044 (19)	0.0208 (19)	−0.0020 (18)
C2	0.085 (3)	0.060 (3)	0.061 (2)	−0.004 (2)	0.025 (2)	−0.018 (2)
C3	0.055 (2)	0.075 (3)	0.0397 (18)	0.006 (2)	0.0074 (16)	−0.003 (2)
C4	0.064 (2)	0.060 (2)	0.0416 (18)	−0.0034 (19)	0.0088 (16)	0.0066 (18)
C5	0.054 (2)	0.053 (2)	0.0346 (16)	0.0027 (17)	−0.0006 (14)	0.0016 (16)
C6	0.113 (4)	0.050 (2)	0.042 (2)	0.010 (2)	0.021 (2)	0.0092 (19)
C7	0.102 (3)	0.036 (2)	0.051 (2)	−0.003 (2)	0.020 (2)	−0.0003 (17)
C8	0.0510 (19)	0.0365 (18)	0.0405 (17)	−0.0020 (14)	0.0061 (14)	−0.0032 (15)
C9	0.0465 (18)	0.0348 (18)	0.0409 (18)	−0.0039 (14)	0.0070 (14)	0.0018 (14)
C10	0.0495 (19)	0.047 (2)	0.0384 (18)	−0.0036 (15)	0.0060 (14)	−0.0034 (15)
C11	0.086 (3)	0.0362 (19)	0.050 (2)	−0.0118 (18)	0.0216 (19)	−0.0050 (16)
C12	0.085 (3)	0.0357 (19)	0.050 (2)	−0.0062 (19)	0.0231 (19)	0.0051 (17)
C13	0.055 (2)	0.042 (2)	0.0445 (18)	−0.0049 (16)	0.0125 (15)	−0.0012 (15)
C14	0.0404 (18)	0.0390 (18)	0.048 (2)	−0.0006 (14)	0.0080 (14)	−0.0045 (15)
C15	0.067 (2)	0.0405 (19)	0.0453 (19)	−0.0060 (17)	0.0097 (16)	−0.0090 (16)
C16	0.075 (3)	0.050 (2)	0.058 (2)	0.005 (2)	0.012 (2)	−0.0146 (19)
N17	0.077 (3)	0.080 (3)	0.099 (3)	0.020 (2)	−0.004 (2)	−0.018 (3)
C18	0.054 (2)	0.071 (3)	0.068 (2)	−0.018 (2)	0.0166 (18)	−0.004 (2)
C19	0.052 (2)	0.114 (4)	0.056 (2)	−0.015 (3)	0.0027 (17)	−0.016 (3)
O20	0.097 (2)	0.095 (3)	0.0592 (18)	0.006 (2)	0.0358 (15)	−0.0064 (18)
O21	0.0576 (16)	0.082 (2)	0.0416 (13)	0.0019 (14)	0.0165 (11)	−0.0036 (13)
C22	0.054 (2)	0.045 (2)	0.0438 (17)	−0.0029 (16)	0.0183 (15)	0.0019 (16)
N23	0.072 (2)	0.095 (3)	0.0470 (18)	0.014 (2)	0.0178 (16)	−0.008 (2)
N24	0.081 (2)	0.092 (3)	0.0412 (17)	0.010 (2)	0.0188 (16)	−0.0081 (19)
C25	0.070 (2)	0.072 (3)	0.0379 (17)	−0.009 (2)	0.0151 (17)	0.0050 (19)
C26	0.083 (3)	0.147 (6)	0.054 (2)	−0.003 (4)	0.010 (2)	−0.002 (3)

Geometric parameters (Å, º)

C1—C2	1.539 (6)	C11—H11B	0.9700
C1—C10	1.539 (6)	C12—C13	1.536 (5)
C1—H1A	0.9700	C12—H12A	0.9700
C1—H1B	0.9700	C12—H12B	0.9700
C2—C3	1.483 (6)	C13—C22	1.502 (5)
C2—H2A	0.9700	C13—C18	1.540 (5)
C2—H2B	0.9700	C13—C14	1.554 (5)
C3—O20	1.224 (5)	C14—C15	1.546 (5)
C3—C4	1.444 (6)	C14—H14	0.9800
C4—C5	1.346 (5)	C15—C16	1.456 (7)
C4—H4	0.9300	C15—H15A	0.9700
C5—C6	1.500 (6)	C15—H15B	0.9700
C5—C10	1.508 (5)	C16—N17	1.139 (6)
C6—C7	1.520 (6)	C18—H18A	0.9600
C6—H6A	0.9700	C18—H18B	0.9600
C6—H6B	0.9700	C18—H18C	0.9600
C7—C8	1.535 (5)	C19—H19A	0.9600
C7—H7A	0.9700	C19—H19B	0.9600
C7—H7B	0.9700	C19—H19C	0.9600
C8—C9	1.534 (5)	O21—C25	1.352 (5)
C8—C14	1.542 (5)	O21—C22	1.354 (5)
C8—H8	0.9800	C22—N23	1.269 (5)
C9—C11	1.529 (5)	N23—N24	1.418 (5)
C9—C10	1.559 (5)	N24—C25	1.251 (6)
C9—H9	0.9800	C25—C26	1.478 (7)
C10—C19	1.537 (6)	C26—H26A	0.9600
C11—C12	1.519 (5)	C26—H26B	0.9600
C11—H11A	0.9700	C26—H26C	0.9600
C2—C1—C10	113.5 (4)	C9—C11—H11B	109.2
C2—C1—H1A	108.9	H11A—C11—H11B	107.9
C10—C1—H1A	108.9	C11—C12—C13	112.5 (3)
C2—C1—H1B	108.9	C11—C12—H12A	109.1
C10—C1—H1B	108.9	C13—C12—H12A	109.1
H1A—C1—H1B	107.7	C11—C12—H12B	109.1
C3—C2—C1	111.8 (3)	C13—C12—H12B	109.1
C3—C2—H2A	109.2	H12A—C12—H12B	107.8
C1—C2—H2A	109.2	C22—C13—C12	108.6 (3)
C3—C2—H2B	109.2	C22—C13—C18	107.4 (3)
C1—C2—H2B	109.2	C12—C13—C18	110.8 (3)
H2A—C2—H2B	107.9	C22—C13—C14	109.2 (3)
O20—C3—C4	120.7 (4)	C12—C13—C14	107.7 (3)
O20—C3—C2	121.5 (4)	C18—C13—C14	113.0 (3)
C4—C3—C2	117.7 (3)	C8—C14—C15	112.2 (3)
C5—C4—C3	123.6 (4)	C8—C14—C13	113.3 (3)
C5—C4—H4	118.2	C15—C14—C13	113.1 (3)
C3—C4—H4	118.2	C8—C14—H14	105.8
C4—C5—C6	119.9 (4)	C15—C14—H14	105.8
C4—C5—C10	122.9 (4)	C13—C14—H14	105.8
C6—C5—C10	117.0 (3)	C16—C15—C14	115.9 (3)
C5—C6—C7	112.0 (3)	C16—C15—H15A	108.3
C5—C6—H6A	109.2	C14—C15—H15A	108.3
C7—C6—H6A	109.2	C16—C15—H15B	108.3
C5—C6—H6B	109.2	C14—C15—H15B	108.3
C7—C6—H6B	109.2	H15A—C15—H15B	107.4
H6A—C6—H6B	107.9	N17—C16—C15	178.4 (5)
C6—C7—C8	111.6 (4)	C13—C18—H18A	109.5
C6—C7—H7A	109.3	C13—C18—H18B	109.5
C8—C7—H7A	109.3	H18A—C18—H18B	109.5
C6—C7—H7B	109.3	C13—C18—H18C	109.5
C8—C7—H7B	109.3	H18A—C18—H18C	109.5
H7A—C7—H7B	108.0	H18B—C18—H18C	109.5
C9—C8—C7	109.6 (3)	C10—C19—H19A	109.5
C9—C8—C14	111.2 (3)	C10—C19—H19B	109.5
C7—C8—C14	110.9 (3)	H19A—C19—H19B	109.5
C9—C8—H8	108.4	C10—C19—H19C	109.5
C7—C8—H8	108.4	H19A—C19—H19C	109.5
C14—C8—H8	108.4	H19B—C19—H19C	109.5
C11—C9—C8	110.9 (3)	C25—O21—C22	103.4 (3)
C11—C9—C10	113.1 (3)	N23—C22—O21	111.4 (3)
C8—C9—C10	114.1 (3)	N23—C22—C13	129.5 (3)
C11—C9—H9	106.0	O21—C22—C13	119.1 (3)
C8—C9—H9	106.0	C22—N23—N24	106.5 (3)
C10—C9—H9	106.0	C25—N24—N23	106.0 (3)
C5—C10—C19	108.5 (3)	N24—C25—O21	112.7 (4)
C5—C10—C1	109.3 (3)	N24—C25—C26	129.3 (4)
C19—C10—C1	110.2 (4)	O21—C25—C26	118.0 (4)
C5—C10—C9	109.4 (3)	C25—C26—H26A	109.5
C19—C10—C9	111.2 (3)	C25—C26—H26B	109.5
C1—C10—C9	108.2 (3)	H26A—C26—H26B	109.5
C12—C11—C9	111.9 (3)	C25—C26—H26C	109.5
C12—C11—H11A	109.2	H26A—C26—H26C	109.5
C9—C11—H11A	109.2	H26B—C26—H26C	109.5
C12—C11—H11B	109.2
C10—C1—C2—C3	−51.9 (5)	C9—C11—C12—C13	−58.1 (5)
C1—C2—C3—O20	−157.6 (4)	C11—C12—C13—C22	174.6 (3)
C1—C2—C3—C4	26.1 (5)	C11—C12—C13—C18	−67.7 (4)
O20—C3—C4—C5	−173.6 (4)	C11—C12—C13—C14	56.4 (4)
C2—C3—C4—C5	2.8 (6)	C9—C8—C14—C15	−175.8 (3)
C3—C4—C5—C6	168.9 (4)	C7—C8—C14—C15	−53.6 (4)
C3—C4—C5—C10	−6.5 (6)	C9—C8—C14—C13	54.6 (4)
C4—C5—C6—C7	133.7 (4)	C7—C8—C14—C13	176.8 (3)
C10—C5—C6—C7	−50.7 (5)	C22—C13—C14—C8	−172.9 (3)
C5—C6—C7—C8	53.7 (5)	C12—C13—C14—C8	−55.1 (4)
C6—C7—C8—C9	−56.2 (4)	C18—C13—C14—C8	67.6 (4)
C6—C7—C8—C14	−179.3 (3)	C22—C13—C14—C15	58.0 (4)
C7—C8—C9—C11	−175.6 (4)	C12—C13—C14—C15	175.8 (3)
C14—C8—C9—C11	−52.7 (4)	C18—C13—C14—C15	−61.5 (4)
C7—C8—C9—C10	55.3 (4)	C8—C14—C15—C16	−47.1 (4)
C14—C8—C9—C10	178.2 (3)	C13—C14—C15—C16	82.6 (4)
C4—C5—C10—C19	101.3 (4)	C14—C15—C16—N17	178 (100)
C6—C5—C10—C19	−74.2 (4)	C25—O21—C22—N23	−0.7 (5)
C4—C5—C10—C1	−18.9 (5)	C25—O21—C22—C13	−179.3 (3)
C6—C5—C10—C1	165.6 (4)	C12—C13—C22—N23	140.2 (5)
C4—C5—C10—C9	−137.2 (4)	C18—C13—C22—N23	20.3 (6)
C6—C5—C10—C9	47.3 (4)	C14—C13—C22—N23	−102.6 (5)
C2—C1—C10—C5	47.3 (4)	C12—C13—C22—O21	−41.5 (4)
C2—C1—C10—C19	−71.9 (4)	C18—C13—C22—O21	−161.4 (4)
C2—C1—C10—C9	166.3 (3)	C14—C13—C22—O21	75.8 (4)
C11—C9—C10—C5	−177.8 (3)	O21—C22—N23—N24	1.0 (5)
C8—C9—C10—C5	−49.7 (4)	C13—C22—N23—N24	179.4 (4)
C11—C9—C10—C19	−57.8 (5)	C22—N23—N24—C25	−0.9 (5)
C8—C9—C10—C19	70.2 (4)	N23—N24—C25—O21	0.5 (5)
C11—C9—C10—C1	63.3 (4)	N23—N24—C25—C26	178.7 (6)
C8—C9—C10—C1	−168.7 (3)	C22—O21—C25—N24	0.0 (5)
C8—C9—C11—C12	54.7 (4)	C22—O21—C25—C26	−178.4 (5)
C10—C9—C11—C12	−175.6 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C4—H4···O20^i	0.93	2.45	3.329 (5)	157
C26—H26C···N23^ii	0.96	2.50	3.423 (7)	162

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