Diethyl 2-[cyano(toluene-4-sulfinyl)methylene]propanedioate and its Diels–Alder adduct with cyclopentadiene

The thermal Diels–Alder cyclo­additon reaction of diethyl 2-­[cyano­(toluene-4-sulfinyl)­methyl­ene]­propane­dioate, C₁₆H₁₇­NO₅S, with cyclo­penta­diene gave the pure racemates of two of the four possible diastereomers, with a complete π-facial selectivity and a high (80:20) endo/exo-sulfinyl selectivity. X-ray diffraction studies of diethyl 2-[cyano­(toluene-4-sulfinyl)­methyl­ene]­propane­dioate and the major isomer of the cyclo­addition product, namely diethyl 3-cyano-3-(toluene-4-sulfinyl)­bi­cyclo­[2.2.1]­hepta-5-ene-2,2-di­carboxyl­ate, C₂₁H₂₃­NO₅S, reveal that the conformation of the substituents on the acrylo­nitrile moiety produces both steric and electronic effects, which affect the stereoselectivity of the reaction.

S1. Comment

When sulfinylethylenes are used as dienophiles in Diels-Alder reactions, their reactivity and endo selectivity are both moderate or low, unless they bear additional electron-withdrawing groups at the double bond (Arai et al., 1991), the alkoxycarbonyls being the most widely studied such group. The reactivity and stereoselectivity of sulfinyl maleates are usually satisfactory when the reactions are conducted in the presence of a TiCl₄ catalyst, which also frequently promotes the undesirable polymerization of the dienes (Alonso et al., 1994). The incorporation of a third alkoxycarbonyl group into the double bond is not able to solve these problems, since such compounds exhibit lower reactivity than vinyl sulfoxides as well as low π-facial selectivity, probably due to a non-planar structure (Carretero et al., 1995). In diethyl 2-[cyano(toluene-4-sulfinyl)methylene]propanedioate, (I), the replacement of one of the ester groups by a cyano group substantially increases both the reactivity and the stereoselectivity of the cycloaddition reaction. In order to gain an insight into the stereochemistry of this dienophile molecule, we determined its crystal structure, as well as that of its Diels-Alder adduct with cyclopentadiene, diethyl 3-cyano-3-(toluene-4-sulfinyl)bicyclo[2.2.1]hepta-5-ene-2,2-dicarboxylate, (II). \sch

Fig. 1 shows that the acrylonitrile moiety and the ethoxycarbonyl group syn to the cyano group in (I) are essentially coplanar [maximum deviation -0.282 (1) Å for O2], with an s-cis conformation for the C═C—C═O moiety [O1—C1—C2—C4 164.1 (4)°]. The mean plane of the second ethoxycarbonyl group makes a dihedral angle of -59.89 (3)° with the mean plane of the acrylonitrile moiety, while the orientation of the planar p-tolyl sulfinyl group is almost perpendicular [89.02 (2)°], relative to the same plane. This conformation puts atom O5 of the sulfinyl group and O3 of the ethoxy group 0.890 (1) and 1.034 (1) Å, respectively, above the C═C double-bond plane, while the bulky p-tolyl substituent and atom O4 of the carbonyl group point in the opposite direction. This will render only one face of the dienophile double bond exposed and thus the Diels-Alder cycloaddition will be facially selective.

Fig. 2 clearly shows the endo-sulfinyl nature of the major isomer of (II) obtained from the Diels-Alder reaction. Upon cycloaddition, besides the change in hybridization of atoms C2 and C3, the major change in the dienophile moiety is observed in the orientation of the ethoxycarbonyl group syn to the cyano group, which turns from a nearly coplanar conformation to an almost perpendicular conformation [74.77 (1)°]. The S1—O5 bond is trans to C2—C3 and approximately coplanar with the phenyl ring. The two C—S bonds are unequal, S1—C15 being shorter than S1—C3, because of the different hybridization. The endocyclic torsion angles show that the approximated mirror symmetry of the norbornene skeleton is only slightly distorted. The exo-ethoxycarbonyl substituent at C2 adopts a fully extended conformation, while the endo one is twisted, probably due to packing interactions.

The orientation of the phenyl ring in both compounds seems to be stabilized by intramolecular hydrogen bonds involving the ortho-H atoms of the aromatic ring, and the carbonyl atom O4 and the sulfinyl atom O5 [C15—H15···O4 2.47 and C11—H11···O5 2.52 Å in (I), and C20—H20···O4 2.38 and C16—H16···O5 2.61 Å in (II)]. In addition, weak intermolecular hydrogen bonds are observed for (I) [C14—H14···O5(-1 + x, y, z) 2.54 Å] and (II) [C19—H19···N1(x, 1 - y, z - 1/2) 2.62 Å].

The observed high π-facial selectivity (80:20 endo-/exo-sulfinyl) may be explained by invoking the possibility of these reactions taking place on organized structures, (A) or (B) (Fig. 3), resulting from intermolecular hydrogen bonding of molecules. Superposition of the structure of cyclopentadiene (Haumann et al., 1996) over the diethyl 2-[cyano(p-tolylsulfonyl)methylene]propanedioate showed that the organized structure, (A) favours a closer approximation [2.47 (1) versus 2.70 (1) Å] by fitting the space between atoms O3 and O5 [5.027 (4) Å] better than structure (B) does.

Related literature

For related literature, see: Alonso et al. (1994); Arai et al. (1991); Carretero et al. (1995); Haumann et al. (1996).

S2. Experimental

For compound (I), cyanomethyl-p-tolylsulfoxide (5.6 mmol, 1 equivalent) in tetrahydrofuran (10 ml) was deprotonated using a solution of Li-HMDS [n-BuLi (6.7 mmol, 1.2 equivalents) and hexamethyldisilazane (HMDS; 6.7 mmol, 1.2 equivalents) in tetrahydrofuran (40 ml)] at 195 K for 30 min. The resulting anion was further reacted with diethyl oxomalonate (6.2 mmol, 1.1 equivalents), added slowly and stirred for 2 h at 195 K. The reaction was quenched with saturated ammonium chloride solution and extracted with dichloromethane, followed by purification by column chromatography, to give 3,3-diethoxycarbonyl-3-hydroxy-2-p-tolylsulfinylpropionitrile in 78% yield as white crystals (m.p. 394–397 K). Dehydration of this alcohol (4.7 mmol, 1 equivalent) in dichloromethane (65 ml) was performed under an argon atmosphere by treatment with methylsulfonyl chloride (18.8 mmol, 4 equivalents) and diisopropylethylamine (18.8 mmol, 4 equivalents) at 195 K with constant stirring for 2 h. Then water (30 ml) was added, the organic layer was separated and the aqueous layer was extracted with dichloromethane (2 × 20 ml). The combined layers were dried with sodium sulfate and concentrated. The residue was purified by column chromatography and recrystallized from hexane-dichloromethane to afford compound (I) in 66% yield as yellow crystals (m.p. 375–377 K). For compound (II), cyclopentadiene (1.79 mmol, 6 equivalents) was added to a solution of (I) (0.298 mmol, 1 equivalent) in dichloromethane (2 ml) at room temperature under an argon atmosphere. The resulting solution was stirred for 2.5 h. Evaporation of the volatiles under vacuum gave a residue that was analyzed by proton NMR (isomer ratio 80:20 endo-sulfinyl/exo-sulfinyl) and purified by flash chromatography using hexane-ethyl acetate (85:15), to yield compound (II) as a white solid which decomposed at 384–386 K.

S3. Refinement

H atoms were treated as riding, with C—H = 0.93–0.98 Å and U_iso(H) = 1.2U_eq(C). Are these the correct constraints.

Computing details

For both compounds, data collection: XSCANS (Siemens, 1993); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXLTL/PC (Sheldrick, 1990); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The molecular structure of (I) showing the atom-labelling scheme. Displacement ellipsoids are shown at the 30% probability level and H atoms are drawn as small spheres of arbitrary radii.
	Fig. 2. The molecular structure of the Diels-Alder adduct, (II), showing the atom-labelling scheme. Displacement ellipsoids are shown at the 30% probability level and H atoms are drawn as small spheres of arbitrary radii.
	Fig. 3. The hypothetical transition state of the reactants during the Diels-Alder reaction; (A) is the endo arrangement and (B) the exo arrangement.

(I) Diethyl 2-[cyano(toluene-4-sulfinyl)methylene]propanedioate

Crystal data

C16H17NO5S	Z = 2
Mr = 335.37	F(000) = 352
Triclinic, P1	Dx = 1.311 Mg m^−3
a = 8.167 (2) Å	Mo Kα radiation, λ = 0.71073 Å
b = 8.666 (1) Å	Cell parameters from 31 reflections
c = 13.004 (2) Å	θ = 5.0–12.5°
α = 104.01 (1)°	µ = 0.21 mm^−1
β = 103.11 (1)°	T = 293 K
γ = 98.40 (1)°	Prism, light yellow
V = 849.8 (3) Å^3	0.40 × 0.40 × 0.24 mm

Data collection

Siemens P4/PC diffractometer	1985 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.049
Graphite monochromator	θmax = 25.0°, θmin = 1.5°
ω/2θ scans	h = 0→9
Absorption correction: ψ-scan (North et al., 1968)	k = −9→9
Tmin = 0.920, Tmax = 0.948	l = −15→15
3165 measured reflections	3 standard reflections every 97 reflections
2941 independent reflections	intensity decay: 2%

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) = 0.177	H-atom parameters constrained
S = 1.07	w = 1/[σ^2(Fo^2) + (0.0942P)^2 + 0.0905P] where P = (Fo^2 + 2Fc^2)/3
2941 reflections	(Δ/σ)max = 0.002
208 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 > 2σ(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.

H atoms were treated as riding, with C—H = 0.93–0.98 Å and U_iso(H) = 1.2U_eq(C). Are these the correct constraints.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S1	0.25175 (13)	0.65540 (12)	0.69755 (8)	0.0518 (3)
O1	0.1817 (4)	0.8606 (3)	1.0837 (2)	0.0685 (9)
O2	0.3157 (6)	1.0563 (4)	1.0294 (3)	0.0946 (14)
O3	0.3092 (3)	0.5831 (3)	0.9954 (2)	0.0556 (7)
O4	0.0718 (5)	0.5137 (4)	0.8580 (3)	0.1004 (15)
O5	0.3905 (4)	0.7208 (5)	0.6537 (3)	0.0767 (9)
N1	0.3333 (7)	1.0974 (5)	0.7904 (3)	0.0855 (13)
C1	0.2503 (5)	0.9181 (4)	1.0148 (3)	0.0519 (9)
C2	0.2387 (4)	0.7831 (4)	0.9133 (3)	0.0412 (7)
C3	0.1949 (5)	0.6093 (4)	0.9182 (3)	0.0452 (8)
C4	0.2620 (4)	0.8155 (4)	0.8222 (3)	0.0420 (7)
C5	0.3033 (6)	0.9770 (5)	0.8097 (3)	0.0550 (9)
C6	0.1877 (8)	0.9777 (6)	1.1883 (4)	0.0810 (15)
H6A	0.0993	1.0384	1.1763	0.097*
H6B	0.2972	1.0525	1.2175	0.097*
C7	0.1605 (10)	0.8877 (7)	1.2647 (4)	0.104 (2)
H7A	0.2517	0.8309	1.2794	0.125*
H7B	0.0534	0.8094	1.2341	0.125*
H7C	0.1577	0.9605	1.3326	0.125*
C8	0.2809 (6)	0.4244 (4)	1.0178 (3)	0.0565 (10)
H8A	0.3348	0.3503	0.9762	0.068*
H8B	0.1600	0.3783	0.9986	0.068*
C9	0.3605 (7)	0.4578 (5)	1.1399 (4)	0.0679 (12)
H9A	0.3165	0.5427	1.1803	0.082*
H9B	0.4830	0.4928	1.1569	0.082*
H9C	0.3337	0.3608	1.1615	0.082*
C10	0.0531 (5)	0.6851 (4)	0.6183 (3)	0.0458 (8)
C11	0.0547 (5)	0.7569 (5)	0.5346 (3)	0.0551 (9)
H11	0.1611	0.7920	0.5189	0.066*
C12	−0.0984 (6)	0.7780 (5)	0.4740 (3)	0.0573 (10)
H12	−0.0984	0.8269	0.4152	0.069*
C13	−0.2529 (5)	0.7296 (5)	0.4966 (3)	0.0517 (9)
C14	−0.2517 (5)	0.6545 (5)	0.5804 (3)	0.0524 (9)
H14	−0.3577	0.6199	0.5967	0.063*
C15	−0.1006 (5)	0.6301 (5)	0.6403 (3)	0.0507 (9)
H15	−0.1010	0.5758	0.6964	0.061*
C16	−0.4191 (6)	0.7583 (7)	0.4343 (4)	0.0769 (13)
H16A	−0.4564	0.6809	0.3625	0.092*
H16B	−0.3984	0.8651	0.4244	0.092*
H16C	−0.5052	0.7482	0.4731	0.092*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0493 (5)	0.0563 (6)	0.0473 (5)	0.0172 (4)	0.0169 (4)	0.0035 (4)
O1	0.101 (2)	0.0473 (15)	0.0623 (17)	0.0093 (15)	0.0489 (17)	0.0034 (13)
O2	0.174 (4)	0.0405 (17)	0.0628 (18)	−0.002 (2)	0.048 (2)	0.0034 (13)
O3	0.0528 (15)	0.0447 (14)	0.0660 (16)	0.0030 (11)	0.0054 (13)	0.0244 (12)
O4	0.102 (3)	0.0561 (19)	0.100 (3)	−0.0224 (19)	−0.040 (2)	0.0302 (18)
O5	0.0535 (17)	0.114 (3)	0.0644 (18)	0.0209 (17)	0.0306 (15)	0.0127 (17)
N1	0.129 (4)	0.060 (2)	0.073 (2)	0.004 (2)	0.037 (3)	0.028 (2)
C1	0.068 (2)	0.041 (2)	0.0422 (18)	0.0112 (17)	0.0122 (17)	0.0065 (15)
C2	0.0422 (17)	0.0383 (17)	0.0394 (16)	0.0058 (14)	0.0106 (14)	0.0064 (13)
C3	0.052 (2)	0.0415 (18)	0.0401 (17)	0.0095 (16)	0.0124 (16)	0.0088 (14)
C4	0.0403 (17)	0.0401 (17)	0.0432 (17)	0.0066 (13)	0.0127 (14)	0.0076 (13)
C5	0.066 (2)	0.052 (2)	0.0467 (19)	0.0059 (18)	0.0196 (18)	0.0147 (17)
C6	0.120 (4)	0.060 (3)	0.064 (3)	0.022 (3)	0.047 (3)	−0.003 (2)
C7	0.175 (7)	0.071 (3)	0.060 (3)	0.005 (4)	0.048 (4)	0.003 (2)
C8	0.073 (3)	0.0403 (19)	0.060 (2)	0.0130 (18)	0.015 (2)	0.0221 (16)
C9	0.090 (3)	0.060 (3)	0.061 (2)	0.022 (2)	0.020 (2)	0.028 (2)
C10	0.0469 (19)	0.0457 (18)	0.0384 (16)	0.0069 (15)	0.0144 (14)	−0.0007 (13)
C11	0.057 (2)	0.065 (2)	0.0458 (19)	0.0068 (19)	0.0229 (17)	0.0165 (17)
C12	0.067 (3)	0.067 (2)	0.0424 (18)	0.009 (2)	0.0197 (18)	0.0213 (17)
C13	0.057 (2)	0.052 (2)	0.0384 (17)	0.0105 (17)	0.0083 (16)	0.0046 (15)
C14	0.048 (2)	0.061 (2)	0.0474 (19)	0.0041 (17)	0.0162 (16)	0.0144 (16)
C15	0.051 (2)	0.057 (2)	0.0456 (18)	0.0056 (17)	0.0171 (16)	0.0176 (16)
C16	0.070 (3)	0.099 (4)	0.061 (3)	0.019 (3)	0.008 (2)	0.031 (3)

Geometric parameters (Å, º)

S1—O5	1.480 (3)	C13—C14	1.397 (5)
S1—C10	1.803 (4)	C13—C16	1.503 (6)
S1—C4	1.837 (3)	C14—C15	1.376 (5)
O1—C1	1.314 (5)	C6—H6A	0.96
O1—C6	1.473 (5)	C6—H6B	0.96
O2—C1	1.189 (5)	C7—H7A	0.96
O3—C3	1.295 (4)	C7—H7B	0.96
O3—C8	1.470 (4)	C7—H7C	0.96
O4—C3	1.182 (5)	C8—H8A	0.96
N1—C5	1.137 (5)	C8—H8B	0.96
C1—C2	1.511 (4)	C9—H9A	0.96
C2—C4	1.330 (5)	C9—H9B	0.96
C2—C3	1.516 (5)	C9—H9C	0.96
C4—C5	1.447 (5)	C11—H11	0.96
C6—C7	1.439 (7)	C12—H12	0.96
C8—C9	1.510 (6)	C14—H14	0.96
C10—C11	1.380 (5)	C15—H15	0.96
C10—C15	1.392 (5)	C16—H16A	0.96
C11—C12	1.381 (6)	C16—H16B	0.96
C12—C13	1.389 (6)	C16—H16C	0.96
O5—S1—C10	107.03 (19)	C2—C4—S1	122.6 (3)
O5—S1—C4	105.26 (18)	C5—C4—S1	112.2 (3)
C10—S1—C4	94.52 (15	N1—C5—C4	174.0 (4)
C1—O1—C6	117.0 (3)	C7—C6—O1	108.1 (4)
C3—O3—C8	118.6 (3)	O3—C8—C9	105.8 (3)
O2—C1—O1	125.6 (4)	C11—C10—C15	120.9 (4)
O2—C1—C2	123.6 (4)	C11—C10—S1	119.7 (3)
O1—C1—C2	110.7 (3)	C15—C10—S1	119.3 (3)
C4—C2—C1	121.2 (3)	C10—C11—C12	119.2 (4)
C4—C2—C3	121.2 (3)	C11—C12—C13	121.1 (4)
C1—C2—C3	117.6 (3)	C12—C13—C14	118.6 (4)
O4—C3—O3	126.2 (4)	C12—C13—C16	121.5 (4)
O4—C3—C2	122.9 (3)	C14—C13—C16	119.8 (4)
O3—C3—C2	111.0 (3)	C15—C14—C13	120.9 (4)
C2—C4—C5	125.1 (3)	C14—C15—C10	119.2 (3)
C6—O1—C1—O2	−0.5 (7)	O5—S1—C4—C5	37.3 (3)
C6—O1—C1—C2	178.4 (4)	C10—S1—C4—C5	−71.7 (3)
O2—C1—C2—C4	−17.0 (7)	C1—O1—C6—C7	−161.3 (5)
O1—C1—C2—C4	164.1 (4)	C3—O3—C8—C9	−147.6 (4)
O2—C1—C2—C3	164.5 (4)	O5—S1—C10—C11	0.4 (3)
O1—C1—C2—C3	−14.4 (5)	C4—S1—C10—C11	107.9 (3)
C8—O3—C3—O4	−4.7 (6)	O5—S1—C10—C15	178.3 (3)
C8—O3—C3—C2	175.5 (3)	C4—S1—C10—C15	−74.3 (3)
C4—C2—C3—O4	−58.5 (6)	C15—C10—C11—C12	1.7 (6)
C1—C2—C3—O4	119.9 (5)	S1—C10—C11—C12	179.6 (3)
C4—C2—C3—O3	121.3 (4)	C10—C11—C12—C13	0.6 (6)
C1—C2—C3—O3	−60.2 (4)	C11—C12—C13—C14	−1.8 (6)
C1—C2—C4—C5	1.4 (6)	C11—C12—C13—C16	177.4 (4)
C3—C2—C4—C5	179.8 (4)	C12—C13—C14—C15	0.6 (6)
C1—C2—C4—S1	179.2 (3)	C16—C13—C14—C15	−178.6 (4)
C3—C2—C4—S1	−2.4 (5)	C13—C14—C15—C10	1.6 (6)
O5—S1—C4—C2	−140.8 (3)	C11—C10—C15—C14	−2.8 (5)
C10—S1—C4—C2	110.2 (3)	S1—C10—C15—C14	179.3 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C15—H15···O4	0.96	2.47	3.317 (5)	147
C11—H11···O5	0.96	2.52	2.928 (5)	106
C14—H14···O5^i	0.96	2.54	3.357 (5)	143

Symmetry code: (i) x−1, y, z.

(II) Diethyl 3-cyano-3-(toluene-4-sulfinyl)bicyclo[2.2.1]hepta-5-ene-2,2-dicarboxylate

Crystal data

C21H23NO5S	F(000) = 848
Mr = 401.46	Dx = 1.315 Mg m^−3
Monoclinic, Cc	Mo Kα radiation, λ = 0.71073 Å
a = 8.458 (1) Å	Cell parameters from 30 reflections
b = 15.137 (2) Å	θ = 5.1–16.1°
c = 15.930 (3) Å	µ = 0.19 mm^−1
β = 95.98 (2)°	T = 293 K
V = 2028.4 (5) Å^3	Plate, colourless
Z = 4	0.28 × 0.20 × 0.06 mm

Data collection

Siemens P4/PC diffractometer	Rint = 0.000
Radiation source: fine-focus sealed tube	θmax = 27.6°, θmin = 1.5°
Graphite monochromator	h = 0→10
ω/2θ scans	k = 0→19
2587 measured reflections	l = −20→20
2491 independent reflections	3 standard reflections every 97 reflections
1072 reflections with I > 2σ(I)	intensity decay: <3%

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)] = 0.064	H-atom parameters constrained
wR(F^2) = 0.141	w = 1/[σ^2(Fo^2) + (0.037P)^2] where P = (Fo^2 + 2Fc^2)/3
S = 0.96	(Δ/σ)max = 0.024
2491 reflections	Δρmax = 0.27 e Å^−3
253 parameters	Δρmin = −0.30 e Å^−3
2 restraints	Absolute structure: Flack (1983)
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.02 (19)

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 > 2σ(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
S1	0.2756 (2)	0.28889 (15)	0.30155 (14)	0.0502 (6)
O1	0.5745 (6)	0.4888 (4)	0.2581 (4)	0.0500 (15)
O2	0.7800 (7)	0.4779 (4)	0.3604 (4)	0.0584 (17)
O3	0.7475 (7)	0.3444 (4)	0.1938 (4)	0.0611 (17)
O4	0.5284 (7)	0.2582 (4)	0.1959 (4)	0.0611 (18)
O5	0.1643 (6)	0.2887 (4)	0.3700 (4)	0.0703 (19)
N1	0.3755 (10)	0.4899 (6)	0.4233 (5)	0.075 (3)
C1	0.7407 (10)	0.2922 (6)	0.3787 (5)	0.055 (2)
H1	0.8543	0.3030	0.3760	0.066*
C2	0.6220 (9)	0.3492 (5)	0.3166 (5)	0.041 (2)
C3	0.4566 (9)	0.3383 (5)	0.3598 (5)	0.042 (2)
C4	0.5113 (12)	0.2750 (6)	0.4380 (5)	0.063 (3)
H4	0.4387	0.2727	0.4821	0.076*
C5	0.5540 (12)	0.1867 (6)	0.4027 (7)	0.068 (3)
H5	0.4963	0.1346	0.4049	0.081*
C6	0.6805 (13)	0.1964 (6)	0.3668 (6)	0.072 (3)
H6	0.7326	0.1527	0.3393	0.087*
C7	0.6781 (10)	0.3130 (7)	0.4655 (5)	0.062 (3)
H7A	0.7337	0.2809	0.5124	0.074*
H7B	0.6757	0.3756	0.4783	0.074*
C8	0.4104 (10)	0.4224 (5)	0.3947 (5)	0.042 (2)
C9	0.6725 (9)	0.4469 (5)	0.3154 (5)	0.0401 (19)
C10	0.6204 (11)	0.3108 (6)	0.2276 (5)	0.048 (2)
C11	0.6047 (12)	0.5826 (5)	0.2527 (7)	0.068 (3)
H11A	0.7147	0.5940	0.2440	0.082*
H11B	0.5826	0.6111	0.3048	0.082*
C12	0.4915 (14)	0.6182 (6)	0.1785 (8)	0.110 (5)
H12A	0.3832	0.6053	0.1870	0.132*
H12B	0.5167	0.5911	0.1271	0.132*
H12C	0.5051	0.6810	0.1749	0.132*
C13	0.7615 (13)	0.3213 (6)	0.1040 (5)	0.075 (3)
H13A	0.8724	0.3254	0.0939	0.090*
H13B	0.7279	0.2606	0.0941	0.090*
C14	0.6730 (15)	0.3782 (8)	0.0456 (6)	0.108 (5)
H14A	0.7355	0.3954	0.0013	0.130*
H14B	0.6415	0.4299	0.0745	0.130*
H14C	0.5802	0.3470	0.0218	0.130*
C15	0.2076 (10)	0.3775 (5)	0.2309 (5)	0.044 (2)
C16	0.1144 (10)	0.4442 (6)	0.2573 (5)	0.048 (2)
H16	0.0870	0.4457	0.3123	0.058*
C17	0.0567 (10)	0.5095 (6)	0.2002 (6)	0.056 (2)
H17	−0.0051	0.5552	0.2182	0.067*
C18	0.0922 (11)	0.5078 (6)	0.1176 (6)	0.057 (2)
C19	0.1821 (10)	0.4408 (6)	0.0907 (5)	0.056 (2)
H19	0.2064	0.4399	0.0351	0.067*
C20	0.2398 (10)	0.3722 (6)	0.1462 (5)	0.051 (2)
H20	0.2961	0.3250	0.1268	0.061*
C21	0.0345 (12)	0.5785 (7)	0.0549 (6)	0.080 (3)
H21A	0.0859	0.6338	0.0692	0.095*
H21B	−0.0782	0.5850	0.0557	0.095*
H21C	0.0571	0.5608	−0.0005	0.095*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0501 (13)	0.0473 (13)	0.0544 (15)	−0.0108 (12)	0.0104 (11)	0.0012 (13)
O1	0.037 (3)	0.044 (4)	0.066 (4)	0.000 (3)	−0.008 (3)	0.006 (3)
O2	0.054 (4)	0.057 (4)	0.062 (4)	−0.004 (3)	−0.006 (3)	−0.006 (3)
O3	0.055 (4)	0.075 (5)	0.056 (4)	−0.007 (3)	0.021 (3)	0.000 (4)
O4	0.062 (4)	0.054 (4)	0.069 (4)	−0.013 (3)	0.016 (3)	−0.025 (3)
O5	0.047 (4)	0.091 (5)	0.074 (5)	−0.030 (4)	0.016 (3)	0.014 (4)
N1	0.089 (7)	0.072 (6)	0.068 (6)	0.003 (5)	0.025 (5)	−0.022 (5)
C1	0.040 (5)	0.056 (6)	0.068 (7)	−0.002 (4)	−0.003 (4)	0.025 (5)
C2	0.049 (5)	0.031 (4)	0.045 (5)	0.007 (4)	0.009 (4)	0.002 (4)
C3	0.037 (4)	0.047 (5)	0.041 (5)	0.002 (4)	−0.005 (4)	0.005 (4)
C4	0.083 (7)	0.062 (7)	0.047 (6)	−0.026 (6)	0.013 (5)	0.004 (5)
C5	0.071 (7)	0.059 (7)	0.075 (7)	0.017 (5)	0.015 (6)	0.035 (6)
C6	0.100 (9)	0.050 (6)	0.066 (7)	0.026 (6)	0.002 (6)	0.013 (5)
C7	0.068 (6)	0.068 (7)	0.049 (6)	0.009 (5)	0.009 (5)	0.015 (5)
C8	0.054 (5)	0.030 (4)	0.045 (5)	−0.007 (4)	0.019 (4)	0.002 (4)
C9	0.042 (5)	0.041 (5)	0.038 (5)	−0.011 (4)	0.009 (4)	−0.005 (4)
C10	0.054 (5)	0.039 (5)	0.054 (6)	0.020 (4)	0.015 (5)	0.012 (4)
C11	0.060 (6)	0.037 (6)	0.104 (9)	0.003 (5)	−0.006 (6)	0.006 (6)
C12	0.111 (10)	0.044 (6)	0.172 (14)	−0.023 (6)	0.002 (9)	0.037 (8)
C13	0.076 (7)	0.104 (9)	0.050 (6)	−0.004 (6)	0.033 (5)	−0.012 (6)
C14	0.126 (11)	0.149 (13)	0.047 (7)	0.042 (10)	−0.005 (7)	0.016 (8)
C15	0.047 (5)	0.044 (5)	0.041 (5)	−0.005 (4)	0.005 (4)	0.001 (4)
C16	0.041 (5)	0.055 (6)	0.047 (6)	0.003 (4)	0.003 (4)	−0.003 (5)
C17	0.045 (5)	0.060 (6)	0.065 (6)	0.004 (5)	0.012 (5)	−0.011 (5)
C18	0.061 (6)	0.053 (6)	0.055 (6)	−0.014 (5)	−0.002 (5)	−0.006 (5)
C19	0.052 (6)	0.076 (7)	0.040 (5)	−0.011 (5)	0.001 (5)	−0.004 (5)
C20	0.046 (5)	0.056 (6)	0.050 (6)	0.004 (4)	0.001 (4)	−0.018 (5)
C21	0.075 (7)	0.085 (7)	0.073 (7)	0.023 (6)	−0.022 (6)	0.006 (6)

Geometric parameters (Å, º)

S1—O5	1.513 (6)	C18—C19	1.365 (12)
S1—C15	1.807 (8)	C18—C21	1.509 (12)
S1—C3	1.863 (8)	C19—C20	1.417 (11)
O1—C9	1.328 (9)	C1—H1	0.98
O1—C11	1.446 (9)	C4—H4	0.98
O2—C9	1.194 (8)	C5—H5	0.93
O3—C10	1.351 (10)	C6—H6	0.93
O3—C13	1.490 (10)	C7—H7A	0.97
O4—C10	1.188 (10)	C7—H7B	0.97
N1—C8	1.170 (10)	C11—H11A	0.97
C1—C6	1.541 (12)	C11—H11B	0.97
C1—C7	1.565 (12)	C12—H12A	0.96
C1—C2	1.588 (10)	C12—H12B	0.96
C2—C10	1.532 (11)	C12—H12C	0.96
C2—C9	1.540 (10)	C13—H13A	0.97
C2—C3	1.630 (10)	C13—H13B	0.97
C3—C8	1.458 (11)	C14—H14A	0.96
C3—C4	1.602 (11)	C14—H14B	0.96
C4—C5	1.508 (12)	C14—H14C	0.96
C4—C7	1.545 (12)	C16—H16	0.93
C5—C6	1.274 (12)	C17—H17	0.93
C11—C12	1.539 (13)	C19—H19	0.93
C13—C14	1.422 (13)	C20—H20	0.93
C15—C16	1.374 (11)	C21—H21A	0.96
C15—C20	1.405 (10)	C21—H21B	0.96
C16—C17	1.396 (11)	C21—H21C	0.96
C17—C18	1.380 (11)
O5—S1—C15	105.6 (4)	C6—C5—C4	108.1 (10)
O5—S1—C3	100.5 (3)	C5—C6—C1	109.7 (9)
C15—S1—C3	101.8 (4)	C4—C7—C1	93.3 (7)
C9—O1—C11	114.2 (7)	N1—C8—C3	179.1 (9)
C10—O3—C13	116.1 (7)	O2—C9—O1	127.2 (7)
C6—C1—C7	99.2 (7)	O2—C9—C2	124.4 (8)
C6—C1—C2	104.8 (7)	O1—C9—C2	108.3 (7)
C7—C1—C2	101.0 (7)	O4—C10—O3	126.6 (8)
C10—C2—C9	109.2 (6)	O4—C10—C2	126.2 (8)
C10—C2—C1	108.3 (6)	O3—C10—C2	107.1 (8)
C9—C2—C1	111.8 (7)	O1—C11—C12	106.9 (7)
C10—C2—C3	115.3 (6)	C14—C13—O3	113.4 (9)
C9—C2—C3	110.7 (7)	C16—C15—C20	120.7 (8)
C1—C2—C3	101.4 (6)	C16—C15—S1	120.7 (6)
C8—C3—C4	107.0 (7)	C20—C15—S1	118.3 (7)
C8—C3—C2	110.4 (7)	C15—C16—C17	119.6 (8)
C4—C3—C2	101.4 (6)	C18—C17—C16	120.8 (8)
C8—C3—S1	107.5 (6)	C19—C18—C17	119.8 (9)
C4—C3—S1	107.6 (5)	C19—C18—C21	118.1 (9)
C2—C3—S1	121.9 (5)	C17—C18—C21	122.1 (9)
C5—C4—C7	100.9 (8)	C18—C19—C20	121.0 (8)
C5—C4—C3	107.5 (7)	C15—C20—C19	118.0 (8)
C7—C4—C3	100.3 (6)
C6—C1—C2—C10	−55.4 (9)	C6—C1—C7—C4	−46.8 (8)
C7—C1—C2—C10	−158.1 (7)	C2—C1—C7—C4	60.4 (8)
C6—C1—C2—C9	−175.7 (7)	C11—O1—C9—O2	−0.8 (12)
C7—C1—C2—C9	81.6 (8)	C11—O1—C9—C2	177.6 (7)
C6—C1—C2—C3	66.3 (9)	C10—C2—C9—O2	−125.5 (8)
C7—C1—C2—C3	−36.4 (8)	C1—C2—C9—O2	−5.7 (11)
C10—C2—C3—C8	−131.3 (7)	C3—C2—C9—O2	106.6 (8)
C9—C2—C3—C8	−6.8 (9)	C10—C2—C9—O1	56.0 (8)
C1—C2—C3—C8	112.0 (7)	C1—C2—C9—O1	175.8 (6)
C10—C2—C3—C4	115.6 (6)	C3—C2—C9—O1	−71.9 (8)
C9—C2—C3—C4	−119.9 (7)	C13—O3—C10—O4	7.9 (12)
C1—C2—C3—C4	−1.1 (8)	C13—O3—C10—C2	−175.1 (7)
C10—C2—C3—S1	−3.7 (9)	C9—C2—C10—O4	−143.6 (8)
C9—C2—C3—S1	120.8 (7)	C1—C2—C10—O4	94.4 (9)
C1—C2—C3—S1	−120.4 (6)	C3—C2—C10—O4	−18.3 (11)
O5—S1—C3—C8	−54.8 (6)	C9—C2—C10—O3	39.4 (8)
C15—S1—C3—C8	53.8 (6)	C1—C2—C10—O3	−82.6 (7)
O5—S1—C3—C4	60.2 (6)	C3—C2—C10—O3	164.7 (6)
C15—S1—C3—C4	168.7 (6)	C9—O1—C11—C12	174.9 (7)
O5—S1—C3—C2	176.4 (6)	C10—O3—C13—C14	85.0 (10)
C15—S1—C3—C2	−75.1 (7)	O5—S1—C15—C16	20.3 (8)
C8—C3—C4—C5	178.0 (7)	C3—S1—C15—C16	−84.3 (7)
C2—C3—C4—C5	−66.2 (9)	O5—S1—C15—C20	−153.9 (6)
S1—C3—C4—C5	62.7 (8)	C3—S1—C15—C20	101.5 (7)
C8—C3—C4—C7	−77.0 (8)	C20—C15—C16—C17	−2.7 (12)
C2—C3—C4—C7	38.8 (8)	S1—C15—C16—C17	−176.8 (6)
S1—C3—C4—C7	167.7 (6)	C15—C16—C17—C18	0.0 (13)
C7—C4—C5—C6	−35.6 (10)	C16—C17—C18—C19	1.4 (13)
C3—C4—C5—C6	69.0 (10)	C16—C17—C18—C21	−178.7 (9)
C4—C5—C6—C1	3.0 (11)	C17—C18—C19—C20	0.1 (13)
C7—C1—C6—C5	29.9 (10)	C21—C18—C19—C20	−179.9 (8)
C2—C1—C6—C5	−74.1 (10)	C16—C15—C20—C19	4.0 (12)
C5—C4—C7—C1	49.6 (8)	S1—C15—C20—C19	178.2 (6)
C3—C4—C7—C1	−60.7 (7)	C18—C19—C20—C15	−2.7 (12)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C20—H20···O4	0.93	2.38	3.027 (10)	127
C16—H16···O5	0.93	2.61	2.964 (11)	104
C19—H19···N1^i	0.93	2.62	3.435 (12)	146

Symmetry code: (i) x, −y+1, z−1/2.