5-O-tert-Butyl­diphenyl­silyl-2-C-hydroxy­methyl-2,3-O-isopropyl­idene-2′-O-trifluoro­methane­sulfonyl-d-ribono-1,4-lactone

Simone, M.; Fleet, G.W.J.; Watkin, D.J.

doi:10.1107/S1600536807004436

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 63| Part 3| March 2007| Pages o1088-o1090

https://doi.org/10.1107/S1600536807004436

5-O-tert-Butyldiphenylsilyl-2-C-hydroxymethyl-2,3-O-isopropylidene-2′-O-trifluoromethanesulfonyl-D-ribono-1,4-lactone

Michela Simone,^a ^* George W. J. Fleet ^a and David J. Watkin ^b

^aDepartment of Organic Chemistry, Chemical Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, England, and ^bDepartment of Chemical Crystallography, Chemical Research Laboratory, University of Oxford, Mansfield Road, Oxford OX1 3TA, England
^*Correspondence e-mail: michela_simone@yahoo.co.uk

(Received 22 January 2007; accepted 27 January 2007; online 7 February 2007)

The title compound, C₂₆H₃₁F₃O₈SSi, provides a unique example of the crystal structure of an organic trifluoromethanesulfonate attached to a primary C atom. The absolute configuration is determined by the use of D-ribose as the starting material.

Comment

Sulfonate esters provide a wide range of leaving groups for nucleophilic substitution reactions in organic chemistry (Bentley, 1991 ). A β-oxygen substituent very substantially retards either S_N1 or S_N2 reactions (Shaik, 1983 ); in carbohydrate chemistry, where there is always a β-oxygen, nucleophilic substitutions at secondary carbons are usually too slow if a mesylate or a tosylate is used as a leaving group (Richardson, 1969 ). However trifluoromethanesulfonate (Howells & McCown, 1977 ; Rakita, 2004 ) is an excellent leaving group with a rate increase of around 10⁵ in comparison to tosylate in S_N1 (Takeuchi et al., 1988 ) and S_N2 reactions (Streitwieser et al., 1968 ), and in decarboxylative eliminations (Fleming & Ramarao, 2004 ). Trifluoromethanesulfonates are relatively unstable; few crystal structures of organic trifluoromethanesulfonates have been reported. The first crystal structure of a secondary trifluoromethanesulfonate was reported by Barnes et al. (1996 ) and a further two have been reported (Hung et al., 2001 ; Tremmel et al., 2003 ). Although two crystal structures of primary trifluoromethanesulfonates of carboranes have been published (Herzog et al., 1999 ; Kalinin et al., 2005 ), the present paper reports the first example of the crystal structure of a primary trifluoromethanesulfonate, (3).

In a study of secondary structures of novel peptides (Jockusch et al., 2006 ), the synthesis of a number of carbon-branched sugar amino acids (Simone et al., 2005 ) required displacements by nucleophiles (X⁻ = N₃⁻, I⁻) of the leaving group in the very hindered neopentyl trifluoromethanesulfonate (3), yielding (4). D-Ribose was converted to the protected hamamelonolactone (1) (Ho, 1979 , 1985 ) as previously described. The less hindered primary alcohol in (1) was selectively protected as the very bulky tert-butyldiphenylsilyl ether (2). Esterification of the remaining neopentyl alcohol in (2) with trifluoromethanesulfonic (triflic) anhydride gave the trifluoromethanesulfonate (3) as a stable crystalline compound, allowing the first X-ray crystallographic analysis of a primary organic trifluoromethanesulfonate. The crystal structure of (3) confirmed the relative stereochemistry and the integrity of the trifluoromethanesulfonate functional group; the absolute configuration of (3) was determined by the use of D-ribose as the starting material.

There are no unusual bond lengths or angles in the structure (Fig. 1), the largest differences from the Mogul norms (Bruno et al., 2004 ) being O8—Si1 (0.02 Å; Mogul s.u. 0.01 Å) and S1—O5—O4 (5.9°; Mogul s.u. 3.7°). The Flack parameter refined to −0.04 (7), enabling the absolute configuration of the molecule to be assigned with confidence.

The crystal structure consists of discrete molecules without any specific strong interactions between them. The molecules are well separated in the b and c directions, giving the appearance of columns in close contact, parallel to a (Fig. 2).

Figure 1
The molecular structure of (3), with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitrary radius.

Figure 2
Packing diagram of (3) viewed along the c axis, showing the columns of molecules lying parallel to a.

Experimental

Triflic anhydride (97 µl, 0.58 mmol) was added dropwise to a stirred solution of the silyl ether (2) (203 mg, 0.44 mmol) in dichloromethane (1.7 ml) containing dry pyridine (79 µl) at 243 K under an atmosphere of argon. After 20 min, thin layer chromatography (ethyl acetate/cyclohexane, 1:4) indicated the presence of a major UV-active product (R_f = 0.45) and complete consumption of the starting material (R_f = 0.11). The reaction mixture was diluted with dichloromethane (20 ml), and washed with aqueous hydrochloric acid solution (1M, 2.0 ml), then with a buffer solution [pH 7, K₂H₂PO₄ (0.51 M)/NaOH (0.38 M), 1.0 ml]. The organic layers were dried (magnesium sulfate) and filtered, and the filtrate was concentrated in vacuo to give a residue which was purified by flash column chromatography (ethyl acetate/cyclohexane, 1:6 to 1:3), to yield the trifluoromethanesulfonate (3) (239 mg, 91% yield) as a colourless oil which crystallized on standing. M.p. 367–370 K; [α]_D²⁵ +9.0 (c, 0.94 in acetonitrile); ν_max (thin film): 1785 (s, C=O) cm⁻¹. A sample of (3), suitable for X-ray crystallographic analysis, was obtained via solvent evaporation (ethyl acetate/cyclohexane).

Crystal data

C₂₆H₃₁F₃O₈SSi
M_r = 588.67
Orthorhombic, P 2₁ 2₁ 2₁
a = 7.7889 (1) Å
b = 17.0479 (3) Å
c = 21.2824 (3) Å
V = 2825.97 (7) Å³
Z = 4
D_x = 1.384 Mg m⁻³
Mo Kα radiation
μ = 0.22 mm⁻¹
T = 150 K
Block, colourless
0.32 × 0.24 × 0.20 mm

Data collection

Nonius KappaCCD diffractometer
ω scans
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997 ) T_min = 0.93, T_max = 0.96
29606 measured reflections
6416 independent reflections
4788 reflections with I > 3σ(I)
R_int = 0.055
θ_max = 27.5°

Refinement

Refinement on F
R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.033
S = 1.06
4788 reflections
353 parameters
H-atom parameters not refined
Chebychev polynomial with three parameters (Carruthers & Watkin, 1979 ) 0.297, 0.0573 and 0.0793
(Δ/σ)_max = 0.002
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.31 e Å⁻³
Absolute structure: Flack (1983 ), 2791 Friedel pairs
Flack parameter: −0.04 (7)

All H atoms were found in difference Fourier maps, but were repositioned geometrically after each cycle of refinement; C—H = 1.00 Å and U_iso(H) = 1.2U_eq(C).

Data collection: COLLECT (Nonius, 2001 ).; cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO/SCALEPACK; program(s) used to solve structure: SIR92 (Altomare et al., 1994 ); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003 ); molecular graphics: CAMERON (Watkin et al., 1996 ); software used to prepare material for publication: CRYSTALS.

Supporting information

Crystal structure: contains datablocks global, 3. DOI: https://doi.org/10.1107/S1600536807004436/wn2114sup1.cif

Structure factors: contains datablock 3. DOI: https://doi.org/10.1107/S1600536807004436/wn21143sup2.hkl

Computing details top

Data collection: COLLECT (Nonius, 2001).; cell refinement: DENZO/SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO/SCALEPACK; program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: CRYSTALS (Betteridge et al., 2003); molecular graphics: CAMERON (Watkin et al., 1996); software used to prepare material for publication: CRYSTALS.

5-O-tert-Butyldiphenylsilyl-2-C-hydroxymethyl- 2,3-O-isopropylidene-2'-O-trifluoromethanesulfonyl-D-ribono-1,4-lactone top

Crystal data top

C₂₆H₃₁F₃O₈SSi	D_x = 1.384 Mg m⁻³
M_r = 588.67	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, P2₁2₁2₁	Cell parameters from 29606 reflections
a = 7.7889 (1) Å	θ = 5–28°
b = 17.0479 (3) Å	µ = 0.22 mm⁻¹
c = 21.2824 (3) Å	T = 150 K
V = 2825.97 (7) Å³	Block, colourless
Z = 4	0.32 × 0.24 × 0.20 mm
F(000) = 1232

Data collection top

Nonius KappaCCD diffractometer	4788 reflections with I > 3σ(I)
Graphite monochromator	R_int = 0.055
ω scans	θ_max = 27.5°, θ_min = 5.2°
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997)	h = −10→10
T_min = 0.93, T_max = 0.96	k = −22→22
29606 measured reflections	l = −27→27
6416 independent reflections

Refinement top

Refinement on F	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters not refined
R[F² > 2σ(F²)] = 0.033	Chebychev polynomial with three parameters (Carruthers & Watkin, 1979) 0.297, 0.0573 and 0.0793
wR(F²) = 0.033	(Δ/σ)_max = 0.002
S = 1.06	Δρ_max = 0.32 e Å⁻³
4788 reflections	Δρ_min = −0.31 e Å⁻³
353 parameters	Absolute structure: Flack (1983), 2791 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.04 (7)

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
O1	0.1132 (2)	−0.09395 (8)	0.30408 (7)	0.0304
C1	0.1544 (3)	−0.05246 (12)	0.35539 (11)	0.0290
C2	0.0421 (3)	0.02148 (11)	0.36056 (9)	0.0236
C3	−0.0810 (3)	0.01558 (11)	0.30473 (9)	0.0232
C4	−0.0154 (3)	−0.05425 (11)	0.2658 (1)	0.0266
O2	0.2640 (2)	−0.07288 (9)	0.39182 (9)	0.0408
C5	0.1602 (2)	0.09126 (12)	0.3645 (1)	0.0265
O3	0.05389 (19)	0.16164 (8)	0.35441 (7)	0.0291
S1	0.11475 (8)	0.24270 (3)	0.37960 (3)	0.0328
O4	0.0571 (3)	0.3005 (1)	0.33682 (9)	0.0519
O5	0.2860 (2)	0.2394 (1)	0.40186 (9)	0.0470
C6	−0.0229 (3)	0.25115 (14)	0.44861 (11)	0.0389
F1	0.0080 (2)	0.1936 (1)	0.48786 (7)	0.0566
F2	−0.18620 (19)	0.24919 (11)	0.43224 (8)	0.0570
F3	0.0084 (3)	0.31886 (9)	0.47665 (8)	0.0614
O6	−0.06340 (17)	0.01953 (8)	0.41459 (6)	0.0262
O7	−0.24526 (17)	0.00347 (8)	0.33208 (7)	0.0273
C7	−0.2262 (3)	−0.01392 (12)	0.39767 (9)	0.0249
C8	−0.3641 (3)	0.02811 (14)	0.43398 (11)	0.0350
C9	−0.2287 (3)	−0.10197 (12)	0.40774 (11)	0.0328
C10	0.0686 (3)	−0.02992 (12)	0.2051 (1)	0.0286
O8	0.19443 (18)	0.02857 (8)	0.21883 (6)	0.0260
Si1	0.28595 (7)	0.08423 (3)	0.16397 (3)	0.0229
C11	0.4132 (3)	0.15675 (11)	0.21083 (9)	0.0240
C12	0.4015 (3)	0.23743 (12)	0.1981 (1)	0.0296
C13	0.4952 (3)	0.29198 (14)	0.23258 (12)	0.0382
C14	0.6027 (3)	0.26699 (14)	0.28012 (11)	0.0380
C15	0.6171 (3)	0.18799 (14)	0.29389 (11)	0.0344
C16	0.5230 (3)	0.13321 (12)	0.2595 (1)	0.0282
C17	0.1131 (3)	0.13991 (11)	0.1223 (1)	0.0268
C18	0.1020 (3)	0.15241 (14)	0.0574 (1)	0.0339
C19	−0.0220 (3)	0.20302 (16)	0.03243 (12)	0.0437
C20	−0.1368 (3)	0.24101 (15)	0.07124 (13)	0.0415
C21	−0.1304 (3)	0.22856 (13)	0.13519 (12)	0.0373
C22	−0.0074 (3)	0.17878 (13)	0.16037 (11)	0.0302
C23	0.4279 (3)	0.02309 (12)	0.1115 (1)	0.0331
C24	0.5407 (3)	0.07733 (15)	0.07131 (13)	0.0450
C25	0.3262 (4)	−0.03198 (15)	0.06794 (13)	0.0462
C26	0.5478 (4)	−0.02684 (17)	0.15282 (14)	0.0520
H31	−0.0879	0.0623	0.2764	0.0278*
H41	−0.1155	−0.0882	0.2547	0.0319*
H51	0.2157	0.0935	0.4069	0.0318*
H52	0.2509	0.0877	0.3314	0.0318*
H81	−0.4788	0.0056	0.4228	0.0421*
H82	−0.3433	0.0214	0.4800	0.0421*
H83	−0.3620	0.0852	0.4232	0.0421*
H91	−0.3436	−0.1232	0.3955	0.0394*
H92	−0.2064	−0.1138	0.4530	0.0394*
H93	−0.1378	−0.1270	0.3813	0.0394*
H101	0.1250	−0.0763	0.1851	0.0343*
H102	−0.0197	−0.0080	0.1759	0.0343*
H121	0.3243	0.2560	0.1636	0.0356*
H131	0.4847	0.3492	0.2229	0.0459*
H141	0.6704	0.3062	0.3047	0.0456*
H151	0.6949	0.1702	0.3284	0.0413*
H161	0.5340	0.0762	0.2697	0.0338*
H181	0.1836	0.1249	0.0286	0.0407*
H191	−0.0273	0.2117	−0.0140	0.0524*
H201	−0.2244	0.2774	0.0531	0.0498*
H211	−0.2144	0.2554	0.1635	0.0448*
H221	−0.0044	0.1703	0.2068	0.0362*
H241	0.6161	0.0450	0.0435	0.0540*
H242	0.6137	0.1106	0.0994	0.0540*
H243	0.4660	0.1118	0.0449	0.0540*
H251	0.4078	−0.0628	0.0414	0.0554*
H252	0.2555	−0.0687	0.0939	0.0554*
H253	0.2490	−0.0002	0.0403	0.0554*
H261	0.6237	−0.0595	0.1254	0.0625*
H262	0.6200	0.0084	0.1795	0.0625*
H263	0.4775	−0.0618	0.1804	0.0625*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0374 (8)	0.0213 (7)	0.0324 (8)	0.0046 (7)	0.0044 (7)	−0.0000 (6)
C1	0.0265 (11)	0.024 (1)	0.0366 (12)	−0.0007 (8)	0.0010 (9)	0.0024 (9)
C2	0.0252 (9)	0.0197 (9)	0.026 (1)	0.0007 (8)	0.0002 (8)	−0.0007 (8)
C3	0.024 (1)	0.0204 (9)	0.025 (1)	−0.0022 (8)	0.0036 (8)	0.0006 (8)
C4	0.0279 (11)	0.021 (1)	0.0307 (11)	−0.0018 (8)	0.0011 (9)	−0.0017 (8)
O2	0.0355 (9)	0.0310 (8)	0.0559 (11)	0.0043 (7)	−0.0122 (8)	0.0044 (8)
C5	0.024 (1)	0.0207 (9)	0.0345 (11)	0.0005 (8)	−0.0006 (8)	−0.0013 (9)
O3	0.0336 (8)	0.0175 (7)	0.0361 (8)	0.0004 (6)	−0.0073 (6)	−0.0029 (6)
S1	0.0389 (3)	0.0194 (2)	0.0401 (3)	−0.0035 (2)	−0.0035 (2)	−0.0006 (2)
O4	0.0789 (14)	0.0265 (8)	0.050 (1)	0.0023 (8)	−0.0019 (11)	0.0130 (8)
O5	0.0369 (9)	0.0346 (9)	0.0696 (12)	−0.0085 (8)	−0.0065 (9)	−0.0110 (9)
C6	0.0456 (14)	0.0291 (12)	0.0421 (13)	0.0050 (11)	−0.0066 (11)	−0.0084 (11)
F1	0.0821 (12)	0.0480 (9)	0.0398 (8)	0.0122 (9)	0.0073 (8)	0.0050 (7)
F2	0.0407 (8)	0.0683 (11)	0.062 (1)	0.0083 (8)	0.0004 (7)	−0.0157 (9)
F3	0.0839 (13)	0.0421 (9)	0.058 (1)	0.0051 (9)	−0.0043 (9)	−0.0248 (8)
O6	0.0255 (7)	0.0303 (8)	0.0229 (7)	−0.0035 (6)	0.0004 (6)	−0.0003 (6)
O7	0.0227 (7)	0.0373 (8)	0.0219 (7)	0.0005 (6)	−0.0003 (6)	0.0025 (6)
C7	0.0248 (9)	0.029 (1)	0.0204 (9)	−0.0032 (8)	−0.0005 (8)	0.0004 (8)
C8	0.0318 (12)	0.0400 (13)	0.0334 (12)	0.001 (1)	0.006 (1)	−0.001 (1)
C9	0.0373 (12)	0.0280 (11)	0.0332 (12)	−0.0058 (9)	−0.001 (1)	0.0040 (9)
C10	0.0369 (12)	0.022 (1)	0.026 (1)	−0.0082 (9)	0.0043 (9)	−0.0037 (8)
O8	0.0292 (8)	0.0235 (7)	0.0252 (7)	−0.0048 (6)	0.0011 (6)	0.0004 (6)
Si1	0.0250 (2)	0.0192 (2)	0.0244 (3)	−0.0008 (2)	0.0023 (2)	0.0000 (2)
C11	0.022 (1)	0.0234 (9)	0.027 (1)	−0.0001 (8)	0.0018 (8)	−0.0003 (8)
C12	0.0323 (11)	0.023 (1)	0.0336 (11)	−0.0007 (9)	−0.004 (1)	0.0039 (8)
C13	0.0421 (13)	0.023 (1)	0.0499 (15)	−0.005 (1)	−0.0059 (12)	−0.001 (1)
C14	0.0355 (12)	0.0378 (12)	0.0406 (13)	−0.0091 (11)	−0.007 (1)	−0.008 (1)
C15	0.0290 (11)	0.0413 (13)	0.0330 (12)	−0.002 (1)	−0.005 (1)	−0.000 (1)
C16	0.0275 (11)	0.0257 (11)	0.0313 (11)	−0.0008 (9)	−0.0026 (9)	0.0026 (9)
C17	0.029 (1)	0.0244 (9)	0.027 (1)	−0.0079 (9)	−0.0007 (9)	0.0011 (8)
C18	0.0353 (12)	0.0389 (12)	0.0275 (11)	−0.005 (1)	−0.003 (1)	−0.0002 (9)
C19	0.0471 (15)	0.0461 (14)	0.0378 (13)	−0.0104 (12)	−0.0190 (12)	0.0129 (11)
C20	0.0305 (12)	0.0347 (12)	0.0594 (15)	−0.005 (1)	−0.0136 (11)	0.0123 (12)
C21	0.0293 (11)	0.0308 (12)	0.0518 (15)	0.0004 (9)	−0.0043 (11)	0.001 (1)
C22	0.027 (1)	0.0280 (11)	0.0350 (11)	0.0002 (8)	−0.002 (1)	−0.0008 (9)
C23	0.0385 (12)	0.026 (1)	0.0347 (12)	−0.0003 (9)	0.010 (1)	−0.0015 (9)
C24	0.0440 (14)	0.0402 (14)	0.0509 (15)	−0.0037 (12)	0.0219 (12)	−0.0045 (12)
C25	0.0615 (18)	0.0327 (12)	0.0443 (15)	−0.0076 (12)	0.0170 (13)	−0.0145 (11)
C26	0.0543 (16)	0.0439 (15)	0.0579 (17)	0.0234 (13)	0.0083 (13)	−0.0010 (13)

Geometric parameters (Å, º) top

O1—C1	1.340 (3)	Si1—C17	1.871 (2)
O1—C4	1.458 (3)	Si1—C23	1.886 (2)
C1—C2	1.538 (3)	C11—C12	1.405 (3)
C1—O2	1.205 (3)	C11—C16	1.401 (3)
C2—C3	1.530 (3)	C12—C13	1.391 (3)
C2—C5	1.506 (3)	C12—H121	1.000
C2—O6	1.414 (2)	C13—C14	1.381 (3)
C3—C4	1.538 (3)	C13—H131	1.000
C3—O7	1.421 (2)	C14—C15	1.383 (3)
C3—H31	1.0000	C14—H141	1.000
C4—C10	1.506 (3)	C15—C16	1.395 (3)
C4—H41	1.000	C15—H151	1.000
C5—O3	1.474 (2)	C16—H161	1.000
C5—H51	1.000	C17—C18	1.399 (3)
C5—H52	1.000	C17—C22	1.407 (3)
O3—S1	1.5563 (14)	C18—C19	1.400 (3)
S1—O4	1.4146 (18)	C18—H181	1.000
S1—O5	1.4166 (18)	C19—C20	1.379 (4)
S1—C6	1.824 (3)	C19—H191	1.000
C6—F1	1.310 (3)	C20—C21	1.378 (4)
C6—F2	1.319 (3)	C20—H201	1.000
C6—F3	1.322 (3)	C21—C22	1.387 (3)
O6—C7	1.436 (2)	C21—H211	1.000
O7—C7	1.435 (2)	C22—H221	1.000
C7—C8	1.505 (3)	C23—C24	1.536 (3)
C7—C9	1.516 (3)	C23—C25	1.539 (3)
C8—H81	1.000	C23—C26	1.539 (3)
C8—H82	1.000	C24—H241	1.000
C8—H83	1.000	C24—H242	1.000
C9—H91	1.000	C24—H243	1.000
C9—H92	1.000	C25—H251	1.000
C9—H93	1.000	C25—H252	1.000
C10—O8	1.428 (2)	C25—H253	1.000
C10—H101	1.000	C26—H261	1.000
C10—H102	1.000	C26—H262	1.000
O8—Si1	1.6648 (14)	C26—H263	1.000
Si1—C11	1.872 (2)

C1—O1—C4	112.00 (15)	C10—O8—Si1	123.29 (12)
O1—C1—C2	110.79 (18)	O8—Si1—C11	103.27 (8)
O1—C1—O2	122.78 (19)	O8—Si1—C17	108.29 (9)
C2—C1—O2	126.4 (2)	C11—Si1—C17	107.38 (9)
C1—C2—C3	104.29 (16)	O8—Si1—C23	110.57 (9)
C1—C2—C5	107.68 (16)	C11—Si1—C23	111.7 (1)
C3—C2—C5	118.56 (17)	C17—Si1—C23	114.9 (1)
C1—C2—O6	111.69 (16)	Si1—C11—C12	120.62 (15)
C3—C2—O6	105.43 (15)	Si1—C11—C16	121.83 (15)
C5—C2—O6	109.16 (16)	C12—C11—C16	117.55 (19)
C2—C3—C4	105.13 (16)	C11—C12—C13	121.3 (2)
C2—C3—O7	104.81 (15)	C11—C12—H121	119.4
C4—C3—O7	114.04 (16)	C13—C12—H121	119.4
C2—C3—H31	116.77	C12—C13—C14	119.9 (2)
C4—C3—H31	107.99	C12—C13—H131	120.1
O7—C3—H31	108.30	C14—C13—H131	120.1
O1—C4—C3	106.67 (16)	C13—C14—C15	120.3 (2)
O1—C4—C10	107.98 (17)	C13—C14—H141	119.8
C3—C4—C10	113.14 (16)	C15—C14—H141	119.8
O1—C4—H41	113.58	C14—C15—C16	119.9 (2)
C3—C4—H41	108.45	C14—C15—H151	120.1
C10—C4—H41	107.16	C16—C15—H151	120.1
C2—C5—O3	106.94 (15)	C11—C16—C15	121.12 (19)
C2—C5—H51	110.10	C11—C16—H161	119.4
O3—C5—H51	110.10	C15—C16—H161	119.4
C2—C5—H52	110.10	Si1—C17—C18	126.14 (18)
O3—C5—H52	110.10	Si1—C17—C22	116.46 (16)
H51—C5—H52	109.47	C18—C17—C22	117.1 (2)
C5—O3—S1	120.09 (13)	C17—C18—C19	120.7 (2)
O3—S1—O4	107.4 (1)	C17—C18—H181	119.6
O3—S1—O5	111.51 (9)	C19—C18—H181	119.6
O4—S1—O5	122.81 (12)	C18—C19—C20	120.6 (2)
O3—S1—C6	99.7 (1)	C18—C19—H191	119.7
O4—S1—C6	106.06 (12)	C20—C19—H191	119.7
O5—S1—C6	106.70 (11)	C19—C20—C21	119.7 (2)
S1—C6—F1	110.25 (17)	C19—C20—H201	120.2
S1—C6—F2	110.61 (16)	C21—C20—H201	120.2
F1—C6—F2	109.1 (2)	C20—C21—C22	120.1 (2)
S1—C6—F3	108.90 (18)	C20—C21—H211	120.0
F1—C6—F3	109.4 (2)	C22—C21—H211	120.0
F2—C6—F3	108.6 (2)	C17—C22—C21	121.7 (2)
C2—O6—C7	108.58 (14)	C17—C22—H221	119.1
C3—O7—C7	109.59 (14)	C21—C22—H221	119.1
O6—C7—O7	104.67 (14)	Si1—C23—C24	109.42 (15)
O6—C7—C8	108.21 (16)	Si1—C23—C25	113.07 (16)
O7—C7—C8	109.10 (17)	C24—C23—C25	109.1 (2)
O6—C7—C9	111.66 (17)	Si1—C23—C26	108.83 (16)
O7—C7—C9	109.92 (16)	C24—C23—C26	107.7 (2)
C8—C7—C9	112.92 (17)	C25—C23—C26	108.6 (2)
C7—C8—H81	109.5	C23—C24—H241	109.5
C7—C8—H82	109.5	C23—C24—H242	109.5
H81—C8—H82	109.5	H241—C24—H242	109.5
C7—C8—H83	109.47	C23—C24—H243	109.5
H81—C8—H83	109.5	H241—C24—H243	109.5
H82—C8—H83	109.5	H242—C24—H243	109.5
C7—C9—H91	109.5	C23—C25—H251	109.5
C7—C9—H92	109.47	C23—C25—H252	109.5
H91—C9—H92	109.5	H251—C25—H252	109.5
C7—C9—H93	109.47	C23—C25—H253	109.5
H91—C9—H93	109.5	H251—C25—H253	109.5
H92—C9—H93	109.5	H252—C25—H253	109.5
C4—C10—O8	108.39 (16)	C23—C26—H261	109.5
C4—C10—H101	109.74	C23—C26—H262	109.5
O8—C10—H101	109.74	H261—C26—H262	109.5
C4—C10—H102	109.74	C23—C26—H263	109.5
O8—C10—H102	109.74	H261—C26—H263	109.5
H101—C10—H102	109.47	H262—C26—H263	109.5

Acknowledgements

Financial support (to MS) provided through the European Community's Human Potential Programme under contract HPRN-CT-2002-00173 is gratefully acknowledged.

References

Altomare, A., Cascarano, G., Giacovazzo, G., Guagliardi, A., Burla, M. C., Polidori, G. & Camalli, M. (1994). J. Appl. Cryst. 27, 435. CrossRef Web of Science IUCr Journals Google Scholar
Barnes, J. C., Brimacombe, J. S. & Kabir, A. K. M. S. (1996). Acta Cryst. C52, 416–418. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Bentley, T. W. (1991). The Chemistry of Sulphonic Acids, Esters and their Derivatives, edited by S. Patai & S. Rappoport, pp. 671–696. Chichester: Wiley. Google Scholar
Betteridge, P. W., Carruthers, J. R., Cooper, R. I., Prout, K. & Watkin, D. J. (2003). J. Appl. Cryst. 36, 1487. Web of Science CrossRef IUCr Journals Google Scholar
Bruno, I. J., Cole, J. C., Kessler, M., Jie, L., Motherwell, W. D. S., Purkis, L. H., Smith, B. R., Taylor, R., Cooper, R. I., Harris, S. E. & Orpen, A. G. (2004). J. Chem. Inf. Comput. Sci. 44, 2133–2144. Web of Science CrossRef PubMed CAS Google Scholar
Carruthers, J. R. & Watkin, D. J. (1979). Acta Cryst. A35, 698–699. CrossRef CAS IUCr Journals Web of Science Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Fleming, I. & Ramarao, C. (2004). Org. Biomol. Chem. 2, 1504–1510. Web of Science CrossRef PubMed CAS Google Scholar
Herzog, A., Knobler, C. B., Hawthorne, M. F., Maderna, A. & Siebert, W. (1999). J. Org. Chem. 64, 1045–1048. Web of Science CSD CrossRef PubMed CAS Google Scholar
Ho, P.-T. (1979). Can. J. Chem. 57, 381. CrossRef Web of Science Google Scholar
Ho, P.-T. (1985). Can. J. Chem. 63, 2221–2224. CrossRef CAS Web of Science Google Scholar
Howells, R. D. & McCown, J. D. (1977). Chem. Rev. 77, 69–92. CrossRef CAS Web of Science Google Scholar
Hung, S. C., Wang, C. C., Chang, S. W. & Chen, C. S. (2001). Tetrahedron Lett. 42, 1321–1324. Web of Science CSD CrossRef CAS Google Scholar
Jockusch, R. A., Talbot, F. O., Simone, M. I., Rogers, P. S., Fleet, G. W. J. & Simons, J. P. (2006). J. Am. Chem. Soc. 128, 16771–16777. Web of Science CrossRef PubMed CAS Google Scholar
Kalinin, V. N., Rys, E. G., Tyutyunov, A. A., Starikov, Z. A., Korlyukov, A. A., Ol'shevskaya, V. A., Sung, D. D., Ponomaryov, A. B., Petrovskii, P. V. & Hey-Hawkins, E. (2005). Dalton Trans. pp. 903–908. Web of Science CSD CrossRef Google Scholar
Nonius (2001). COLLECT. Nonius BV, Delft, The Netherlands. Google Scholar
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press. Google Scholar
Rakita, P. E. (2004). Chim. Oggi, 22, 48–50. CAS Google Scholar
Richardson, A. C. (1969). Carbohydr. Res. 10, 395–402. CrossRef CAS Web of Science Google Scholar
Shaik, S. S. (1983). J. Am. Chem. Soc. 105, 4359–4367. CrossRef CAS Web of Science Google Scholar
Simone, M. I., Soengas, R., Newton, C. R., Watkin, D. J. & Fleet, G. W. J. (2005). Tetrahedron Lett. 46, 5761–5765. Web of Science CSD CrossRef CAS Google Scholar
Streitwieser, A., Wilkins, C. L. & Kiehlmann, E. (1968). J. Am. Chem. Soc. 90, 1598–1601. CrossRef CAS Google Scholar
Takeuchi, K., Ikai, K., Shibata, T. & Tsugeno, A. (1988). J. Org. Chem. 53, 2852–2855. CrossRef CAS Web of Science Google Scholar
Tremmel, P., Brand, J., Knapp, V. & Geyer, A. (2003). Eur. J. Org. Chem. pp. 878–884. CSD CrossRef Google Scholar
Watkin, D. J., Prout, C. K. & Pearce, L. J. (1996). CAMERON. Chemical Crystallography Laboratory, Oxford, England. Google Scholar

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