The title compound, C5H10O5S2, consists of a five-membered dithiolane ring with two O atoms bonded to each S atom and a methoxymethyl group at the 2-position. The asymmetric unit contains two molecules. A few interatomic close contacts seem to influence the geometry of the dithiolane ring.
Supporting information
CCDC reference: 214806
Key indicators
- Single-crystal X-ray study
- T = 293 K
- Mean (C-C) = 0.003 Å
- R factor = 0.037
- wR factor = 0.103
- Data-to-parameter ratio = 17.2
checkCIF results
No syntax errors found
ADDSYM reports no extra symmetry
The title compound, (I), was prepared, according to a literature method (Aggarwal et al., 1998), from racemic-2-methoxymethyl-1,3-dithiolane 1,3-dioxide (2.7 g, 14.8 mmol) in dry acetonitrile (10 ml) and purified m-CPBA (5.6 g, 32.6 mmol) in ether (50 ml), the mixture being stirred for 3 d at room temperature. Subsequently, a white solid was collected by filtration and crystallized from EtOAc (yield 2.3 g, 73%), m.p. 390 K.
The H-atom positions were located in a difference synthesis and refined isotropically.
Data collection: XSCANS (Siemens, 1996); cell refinement: XSCANS; data reduction: SHELXTL (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX publication routines (Farrugia, 1999).
2-Methoxymethyl-1,3-dithiolane 1,1,3,3-tetraoxide
top
Crystal data top
C5H10O5S2 | Z = 4 |
Mr = 214.25 | F(000) = 448 |
Triclinic, P1 | Dx = 1.620 Mg m−3 |
Hall symbol: -P 1 | Mo Kα radiation, λ = 0.71073 Å |
a = 6.7699 (10) Å | Cell parameters from 25 reflections |
b = 9.1736 (13) Å | θ = 10–15° |
c = 14.5311 (19) Å | µ = 0.59 mm−1 |
α = 77.910 (11)° | T = 293 K |
β = 85.013 (11)° | Prism, colourless |
γ = 86.886 (12)° | 0.35 × 0.25 × 0.20 mm |
V = 878.5 (2) Å3 | |
Data collection top
Siemens P4 diffractometer | Rint = 0.032 |
Radiation source: fine-focus sealed tube | θmax = 30.0°, θmin = 1.4° |
Graphite monochromator | h = 0→9 |
non–profiled ω scans | k = −12→12 |
5527 measured reflections | l = −20→20 |
5125 independent reflections | 2 standard reflections every 50 reflections |
4609 reflections with I > 2σ(I) | intensity decay: 1% |
Refinement top
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.037 | All H-atom parameters refined |
wR(F2) = 0.103 | w = 1/[σ2(Fo2) + (0.0491P)2 + 0.3797P] where P = (Fo2 + 2Fc2)/3 |
S = 1.12 | (Δ/σ)max = 0.001 |
5125 reflections | Δρmax = 0.70 e Å−3 |
298 parameters | Δρmin = −0.43 e Å−3 |
0 restraints | Extinction correction: SHELXL97, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.077 (4) |
Crystal data top
C5H10O5S2 | γ = 86.886 (12)° |
Mr = 214.25 | V = 878.5 (2) Å3 |
Triclinic, P1 | Z = 4 |
a = 6.7699 (10) Å | Mo Kα radiation |
b = 9.1736 (13) Å | µ = 0.59 mm−1 |
c = 14.5311 (19) Å | T = 293 K |
α = 77.910 (11)° | 0.35 × 0.25 × 0.20 mm |
β = 85.013 (11)° | |
Data collection top
Siemens P4 diffractometer | Rint = 0.032 |
5527 measured reflections | 2 standard reflections every 50 reflections |
5125 independent reflections | intensity decay: 1% |
4609 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.037 | 0 restraints |
wR(F2) = 0.103 | All H-atom parameters refined |
S = 1.12 | Δρmax = 0.70 e Å−3 |
5125 reflections | Δρmin = −0.43 e Å−3 |
298 parameters | |
Special details top
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 (Å2) top | x | y | z | Uiso*/Ueq | |
H11 | 0.080 (3) | 0.861 (2) | 0.5810 (15) | 0.032 (5)* | |
H32 | 0.261 (3) | 0.577 (3) | 0.4364 (15) | 0.033 (5)* | |
H31 | 0.257 (4) | 0.701 (3) | 0.349 (2) | 0.054 (7)* | |
H41' | −0.467 (5) | 0.308 (3) | 0.891 (2) | 0.069 (8)* | |
H51' | −0.560 (6) | 0.562 (4) | 0.936 (3) | 0.100 (12)* | |
H11' | −0.721 (3) | 0.116 (3) | 0.9613 (18) | 0.043 (6)* | |
H42 | −0.155 (4) | 0.665 (3) | 0.6361 (19) | 0.054 (7)* | |
H21 | 0.552 (4) | 0.707 (3) | 0.4385 (17) | 0.046 (6)* | |
H21' | −1.052 (4) | −0.017 (3) | 0.7966 (19) | 0.051 (7)* | |
H41 | 0.034 (4) | 0.552 (3) | 0.6574 (19) | 0.057 (7)* | |
H22' | −0.947 (4) | −0.076 (3) | 0.8890 (19) | 0.052 (7)* | |
H42' | −0.626 (4) | 0.354 (3) | 0.8214 (19) | 0.047 (7)* | |
H31' | −0.713 (4) | −0.116 (4) | 0.771 (2) | 0.068 (8)* | |
H32' | −0.758 (4) | 0.050 (3) | 0.718 (2) | 0.062 (8)* | |
H22 | 0.424 (4) | 0.852 (3) | 0.4259 (18) | 0.047 (6)* | |
H51 | −0.137 (5) | 0.679 (4) | 0.858 (3) | 0.084 (10)* | |
H52' | −0.788 (6) | 0.596 (4) | 0.962 (3) | 0.091 (11)* | |
H53' | −0.729 (5) | 0.591 (4) | 0.855 (3) | 0.098 (13)* | |
H52 | −0.291 (8) | 0.675 (6) | 0.794 (4) | 0.135 (18)* | |
H53 | −0.149 (5) | 0.535 (5) | 0.820 (3) | 0.092 (11)* | |
S1 | 0.03484 (6) | 0.75288 (4) | 0.45759 (3) | 0.02964 (11) | |
S2' | −0.96229 (6) | 0.16515 (5) | 0.86322 (3) | 0.03316 (11) | |
S1' | −0.56738 (6) | 0.03167 (5) | 0.83906 (3) | 0.03333 (11) | |
S2 | 0.37186 (6) | 0.72763 (5) | 0.57137 (3) | 0.03454 (11) | |
C1 | 0.1041 (2) | 0.76086 (18) | 0.57463 (11) | 0.0294 (3) | |
O1 | −0.12218 (19) | 0.65123 (17) | 0.46501 (10) | 0.0434 (3) | |
O2 | 0.0040 (2) | 0.90410 (15) | 0.40803 (10) | 0.0482 (4) | |
O2' | −0.5049 (2) | −0.09416 (17) | 0.90770 (11) | 0.0503 (4) | |
C3 | 0.2598 (2) | 0.67979 (19) | 0.41120 (12) | 0.0314 (3) | |
C1' | −0.7129 (3) | 0.1595 (2) | 0.90059 (12) | 0.0325 (3) | |
O3 | 0.4112 (2) | 0.57355 (18) | 0.61281 (11) | 0.0516 (4) | |
O4' | −1.1054 (2) | 0.16727 (19) | 0.94196 (11) | 0.0513 (4) | |
O3' | −0.9746 (2) | 0.27897 (16) | 0.77932 (11) | 0.0482 (3) | |
O1' | −0.4189 (2) | 0.1115 (2) | 0.77474 (11) | 0.0550 (4) | |
C2' | −0.9511 (3) | −0.0111 (2) | 0.83097 (14) | 0.0378 (4) | |
C3' | −0.7546 (3) | −0.0220 (3) | 0.77515 (13) | 0.0398 (4) | |
O5' | −0.7444 (3) | 0.39508 (18) | 0.93943 (13) | 0.0564 (4) | |
O5 | −0.0060 (3) | 0.70611 (18) | 0.73632 (10) | 0.0512 (4) | |
C2 | 0.4231 (3) | 0.7548 (2) | 0.44704 (13) | 0.0367 (3) | |
O4 | 0.4615 (2) | 0.8401 (2) | 0.60728 (12) | 0.0577 (4) | |
C4 | −0.0141 (3) | 0.6557 (2) | 0.65228 (13) | 0.0388 (4) | |
C4' | −0.6260 (3) | 0.3129 (2) | 0.88228 (17) | 0.0471 (4) | |
C5 | −0.1551 (6) | 0.6408 (4) | 0.8056 (2) | 0.0670 (8) | |
C5' | −0.6988 (7) | 0.5484 (3) | 0.9188 (3) | 0.0763 (9) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
S1 | 0.02937 (19) | 0.02793 (18) | 0.03225 (19) | 0.00579 (13) | −0.00780 (14) | −0.00714 (14) |
S2' | 0.0332 (2) | 0.0349 (2) | 0.0309 (2) | 0.00354 (15) | −0.00221 (14) | −0.00710 (15) |
S1' | 0.0301 (2) | 0.0416 (2) | 0.02823 (19) | 0.00257 (15) | −0.00227 (14) | −0.00809 (15) |
S2 | 0.0304 (2) | 0.0412 (2) | 0.0347 (2) | 0.00355 (15) | −0.00834 (15) | −0.01283 (16) |
C1 | 0.0306 (7) | 0.0273 (7) | 0.0314 (7) | 0.0033 (5) | −0.0040 (6) | −0.0091 (6) |
O1 | 0.0305 (6) | 0.0530 (8) | 0.0499 (8) | −0.0050 (5) | −0.0072 (5) | −0.0151 (6) |
O2 | 0.0701 (10) | 0.0316 (6) | 0.0424 (7) | 0.0178 (6) | −0.0194 (7) | −0.0058 (5) |
O2' | 0.0587 (9) | 0.0492 (8) | 0.0423 (7) | 0.0177 (7) | −0.0148 (6) | −0.0086 (6) |
C3 | 0.0309 (7) | 0.0328 (8) | 0.0315 (7) | 0.0009 (6) | −0.0014 (6) | −0.0101 (6) |
C1' | 0.0356 (8) | 0.0369 (8) | 0.0260 (7) | 0.0005 (6) | −0.0044 (6) | −0.0082 (6) |
O3 | 0.0501 (8) | 0.0521 (9) | 0.0480 (8) | 0.0208 (7) | −0.0104 (6) | −0.0030 (6) |
O4' | 0.0423 (8) | 0.0638 (10) | 0.0477 (8) | 0.0056 (7) | 0.0086 (6) | −0.0180 (7) |
O3' | 0.0589 (9) | 0.0411 (7) | 0.0420 (7) | 0.0050 (6) | −0.0168 (6) | 0.0010 (6) |
O1' | 0.0435 (8) | 0.0708 (11) | 0.0481 (8) | −0.0099 (7) | 0.0123 (6) | −0.0108 (7) |
C2' | 0.0359 (9) | 0.0390 (9) | 0.0400 (9) | −0.0023 (7) | −0.0034 (7) | −0.0113 (7) |
C3' | 0.0386 (9) | 0.0512 (11) | 0.0336 (8) | 0.0046 (8) | −0.0057 (7) | −0.0181 (8) |
O5' | 0.0707 (11) | 0.0422 (8) | 0.0617 (10) | −0.0006 (7) | −0.0063 (8) | −0.0229 (7) |
O5 | 0.0679 (10) | 0.0540 (9) | 0.0332 (7) | −0.0185 (7) | 0.0089 (6) | −0.0133 (6) |
C2 | 0.0297 (8) | 0.0423 (9) | 0.0386 (9) | −0.0034 (7) | −0.0009 (6) | −0.0099 (7) |
O4 | 0.0453 (8) | 0.0783 (12) | 0.0626 (10) | −0.0119 (8) | −0.0094 (7) | −0.0397 (9) |
C4 | 0.0421 (9) | 0.0404 (9) | 0.0343 (8) | −0.0069 (7) | 0.0010 (7) | −0.0092 (7) |
C4' | 0.0508 (11) | 0.0419 (10) | 0.0514 (12) | −0.0077 (8) | −0.0041 (9) | −0.0141 (9) |
C5 | 0.087 (2) | 0.0612 (16) | 0.0493 (13) | −0.0149 (14) | 0.0291 (13) | −0.0145 (11) |
C5' | 0.110 (3) | 0.0417 (13) | 0.084 (2) | 0.0035 (14) | −0.032 (2) | −0.0199 (13) |
Geometric parameters (Å, º) top
S1—O1 | 1.4342 (14) | C1'—H11' | 0.89 (2) |
S1—O2 | 1.4363 (14) | C2'—C3' | 1.506 (3) |
S1—C3 | 1.7671 (17) | C2'—H21' | 0.89 (3) |
S1—C1 | 1.8199 (16) | C2'—H22' | 0.93 (3) |
S2'—O3' | 1.4347 (14) | C3'—H31' | 0.90 (3) |
S2'—O4' | 1.4361 (15) | C3'—H32' | 0.94 (3) |
S2'—C2' | 1.7714 (19) | O5'—C4' | 1.407 (3) |
S2'—C1' | 1.8125 (18) | O5'—C5' | 1.420 (3) |
S1'—O2' | 1.4296 (15) | O5—C4 | 1.400 (2) |
S1'—O1' | 1.4320 (15) | O5—C5 | 1.424 (3) |
S1'—C3' | 1.7820 (19) | C2—H21 | 0.97 (3) |
S1'—C1' | 1.8185 (17) | C2—H22 | 0.88 (3) |
S2—O4 | 1.4327 (15) | C4—H42 | 0.99 (3) |
S2—O3 | 1.4359 (16) | C4—H41 | 0.98 (3) |
S2—C2 | 1.7772 (19) | C4'—H41' | 1.09 (3) |
S2—C1 | 1.8197 (17) | C4'—H42' | 0.89 (3) |
C1—C4 | 1.522 (2) | C5—H51 | 0.92 (4) |
C1—H11 | 0.94 (2) | C5—H52 | 0.97 (5) |
C3—C2 | 1.517 (2) | C5—H53 | 0.95 (4) |
C3—H32 | 0.93 (2) | C5'—H51' | 1.02 (4) |
C3—H31 | 0.88 (3) | C5'—H52' | 0.98 (4) |
C1'—C4' | 1.518 (3) | C5'—H53' | 0.97 (4) |
| | | |
O1—S1—O2 | 118.48 (9) | C3'—C2'—H21' | 111.3 (17) |
O1—S1—C3 | 111.07 (8) | S2'—C2'—H21' | 109.6 (17) |
O2—S1—C3 | 108.80 (9) | C3'—C2'—H22' | 108.7 (16) |
O1—S1—C1 | 110.05 (8) | S2'—C2'—H22' | 102.0 (16) |
O2—S1—C1 | 107.00 (8) | H21'—C2'—H22' | 118 (2) |
C3—S1—C1 | 99.74 (8) | C2'—C3'—S1' | 107.96 (13) |
O3'—S2'—O4' | 119.33 (10) | C2'—C3'—H31' | 114 (2) |
O3'—S2'—C2' | 108.49 (10) | S1'—C3'—H31' | 101.5 (19) |
O4'—S2'—C2' | 110.67 (10) | C2'—C3'—H32' | 107.8 (18) |
O3'—S2'—C1' | 108.19 (9) | S1'—C3'—H32' | 106.2 (18) |
O4'—S2'—C1' | 110.18 (9) | H31'—C3'—H32' | 118 (3) |
C2'—S2'—C1' | 97.80 (9) | C4'—O5'—C5' | 112.2 (2) |
O2'—S1'—O1' | 118.19 (11) | C4—O5—C5 | 110.92 (19) |
O2'—S1'—C3' | 109.45 (10) | C3—C2—S2 | 106.13 (12) |
O1'—S1'—C3' | 109.89 (10) | C3—C2—H21 | 113.0 (15) |
O2'—S1'—C1' | 108.25 (9) | S2—C2—H21 | 104.9 (15) |
O1'—S1'—C1' | 109.67 (10) | C3—C2—H22 | 113.7 (16) |
C3'—S1'—C1' | 99.81 (8) | S2—C2—H22 | 106.0 (17) |
O4—S2—O3 | 118.90 (11) | H21—C2—H22 | 112 (2) |
O4—S2—C2 | 110.46 (10) | O5—C4—C1 | 107.72 (15) |
O3—S2—C2 | 108.94 (10) | O5—C4—H42 | 107.8 (16) |
O4—S2—C1 | 109.93 (9) | C1—C4—H42 | 107.3 (15) |
O3—S2—C1 | 108.07 (9) | O5—C4—H41 | 112.6 (16) |
C2—S2—C1 | 98.60 (8) | C1—C4—H41 | 111.7 (16) |
C4—C1—S2 | 115.07 (12) | H42—C4—H41 | 109 (2) |
C4—C1—S1 | 112.20 (12) | O5'—C4'—C1' | 106.16 (18) |
S2—C1—S1 | 105.83 (8) | O5'—C4'—H41' | 115.7 (16) |
C4—C1—H11 | 110.6 (13) | C1'—C4'—H41' | 112.9 (16) |
S2—C1—H11 | 106.3 (13) | O5'—C4'—H42' | 112.5 (17) |
S1—C1—H11 | 106.2 (13) | C1'—C4'—H42' | 109.5 (17) |
C2—C3—S1 | 105.61 (12) | H41'—C4'—H42' | 100 (2) |
C2—C3—H32 | 111.5 (13) | O5—C5—H51 | 105 (2) |
S1—C3—H32 | 105.6 (13) | O5—C5—H52 | 116 (3) |
C2—C3—H31 | 113.9 (18) | H51—C5—H52 | 101 (4) |
S1—C3—H31 | 106.6 (18) | O5—C5—H53 | 114 (2) |
H32—C3—H31 | 113 (2) | H51—C5—H53 | 111 (3) |
C4'—C1'—S2' | 112.57 (14) | H52—C5—H53 | 109 (4) |
C4'—C1'—S1' | 112.62 (13) | O5'—C5'—H51' | 111 (2) |
S2'—C1'—S1' | 106.20 (9) | O5'—C5'—H52' | 106 (2) |
C4'—C1'—H11' | 112.6 (16) | H51'—C5'—H52' | 105 (3) |
S2'—C1'—H11' | 106.0 (15) | O5'—C5'—H53' | 109 (2) |
S1'—C1'—H11' | 106.3 (16) | H51'—C5'—H53' | 117 (3) |
C3'—C2'—S2' | 106.31 (13) | H52'—C5'—H53' | 108 (3) |
| | | |
O4—S2—C1—C4 | −105.37 (15) | O1'—S1'—C1'—C4' | −9.08 (17) |
O3—S2—C1—C4 | 25.86 (15) | C3'—S1'—C1'—C4' | −124.45 (15) |
C2—S2—C1—C4 | 139.11 (13) | O2'—S1'—C1'—S2' | −115.19 (10) |
O4—S2—C1—S1 | 130.13 (10) | O1'—S1'—C1'—S2' | 114.57 (11) |
O3—S2—C1—S1 | −98.64 (10) | C3'—S1'—C1'—S2' | −0.80 (11) |
C2—S2—C1—S1 | 14.61 (10) | O3'—S2'—C2'—C3' | 67.42 (16) |
O1—S1—C1—C4 | 1.79 (15) | O4'—S2'—C2'—C3' | −159.87 (13) |
O2—S1—C1—C4 | 131.76 (14) | C1'—S2'—C2'—C3' | −44.79 (15) |
C3—S1—C1—C4 | −115.02 (13) | S2'—C2'—C3'—S1' | 48.07 (17) |
O1—S1—C1—S2 | 128.06 (9) | O2'—S1'—C3'—C2' | 84.73 (16) |
O2—S1—C1—S2 | −101.98 (10) | O1'—S1'—C3'—C2' | −143.93 (15) |
C3—S1—C1—S2 | 11.25 (10) | C1'—S1'—C3'—C2' | −28.73 (16) |
O1—S1—C3—C2 | −154.90 (12) | S1—C3—C2—S2 | 52.20 (14) |
O2—S1—C3—C2 | 72.96 (14) | O4—S2—C2—C3 | −156.35 (13) |
C1—S1—C3—C2 | −38.87 (13) | O3—S2—C2—C3 | 71.32 (15) |
O3'—S2'—C1'—C4' | 35.54 (16) | C1—S2—C2—C3 | −41.24 (14) |
O4'—S2'—C1'—C4' | −96.53 (15) | C5—O5—C4—C1 | 163.8 (2) |
C2'—S2'—C1'—C4' | 148.00 (14) | S2—C1—C4—O5 | 79.95 (18) |
O3'—S2'—C1'—S1' | −88.14 (11) | S1—C1—C4—O5 | −158.96 (13) |
O4'—S2'—C1'—S1' | 139.79 (10) | C5'—O5'—C4'—C1' | −170.9 (2) |
C2'—S2'—C1'—S1' | 24.32 (11) | S2'—C1'—C4'—O5' | 64.30 (19) |
O2'—S1'—C1'—C4' | 121.16 (15) | S1'—C1'—C4'—O5' | −175.66 (14) |
Experimental details
Crystal data |
Chemical formula | C5H10O5S2 |
Mr | 214.25 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 293 |
a, b, c (Å) | 6.7699 (10), 9.1736 (13), 14.5311 (19) |
α, β, γ (°) | 77.910 (11), 85.013 (11), 86.886 (12) |
V (Å3) | 878.5 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.59 |
Crystal size (mm) | 0.35 × 0.25 × 0.20 |
|
Data collection |
Diffractometer | Siemens P4 diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5527, 5125, 4609 |
Rint | 0.032 |
(sin θ/λ)max (Å−1) | 0.703 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.103, 1.12 |
No. of reflections | 5125 |
No. of parameters | 298 |
H-atom treatment | All H-atom parameters refined |
Δρmax, Δρmin (e Å−3) | 0.70, −0.43 |
Selected geometric parameters (Å, º) topS1—O1 | 1.4342 (14) | S1'—O1' | 1.4320 (15) |
S1—O2 | 1.4363 (14) | S1'—C3' | 1.7820 (19) |
S1—C3 | 1.7671 (17) | S1'—C1' | 1.8185 (17) |
S1—C1 | 1.8199 (16) | S2—O4 | 1.4327 (15) |
S2'—O3' | 1.4347 (14) | S2—O3 | 1.4359 (16) |
S2'—O4' | 1.4361 (15) | S2—C2 | 1.7772 (19) |
S2'—C2' | 1.7714 (19) | S2—C1 | 1.8197 (17) |
S2'—C1' | 1.8125 (18) | C3—C2 | 1.517 (2) |
S1'—O2' | 1.4296 (15) | C2'—C3' | 1.506 (3) |
| | | |
O1—S1—O2 | 118.48 (9) | O2'—S1'—C1' | 108.25 (9) |
O1—S1—C3 | 111.07 (8) | O1'—S1'—C1' | 109.67 (10) |
O2—S1—C3 | 108.80 (9) | C3'—S1'—C1' | 99.81 (8) |
O1—S1—C1 | 110.05 (8) | O4—S2—O3 | 118.90 (11) |
O2—S1—C1 | 107.00 (8) | O4—S2—C2 | 110.46 (10) |
C3—S1—C1 | 99.74 (8) | O3—S2—C2 | 108.94 (10) |
O3'—S2'—O4' | 119.33 (10) | O4—S2—C1 | 109.93 (9) |
O3'—S2'—C2' | 108.49 (10) | O3—S2—C1 | 108.07 (9) |
O4'—S2'—C2' | 110.67 (10) | C2—S2—C1 | 98.60 (8) |
O3'—S2'—C1' | 108.19 (9) | S2—C1—S1 | 105.83 (8) |
O4'—S2'—C1' | 110.18 (9) | C2—C3—S1 | 105.61 (12) |
C2'—S2'—C1' | 97.80 (9) | S2'—C1'—S1' | 106.20 (9) |
O2'—S1'—O1' | 118.19 (11) | C3'—C2'—S2' | 106.31 (13) |
O2'—S1'—C3' | 109.45 (10) | C2'—C3'—S1' | 107.96 (13) |
O1'—S1'—C3' | 109.89 (10) | C3—C2—S2 | 106.13 (12) |
| | | |
C2—S2—C1—S1 | 14.61 (10) | C1'—S2'—C2'—C3' | −44.79 (15) |
C3—S1—C1—S2 | 11.25 (10) | S2'—C2'—C3'—S1' | 48.07 (17) |
C1—S1—C3—C2 | −38.87 (13) | C1'—S1'—C3'—C2' | −28.73 (16) |
C2'—S2'—C1'—S1' | 24.32 (11) | S1—C3—C2—S2 | 52.20 (14) |
C3'—S1'—C1'—S2' | −0.80 (11) | C1—S2—C2—C3 | −41.24 (14) |
Comparison of the bond angles (°) in the dithiolane ring of (I) with the corresponding values in the related compounds (II), (III), (IV), (V) and (VI). Note that s.u. values are not available for (VI). topAngles | (I) | (II) | (III) | (IV) | (V) | (VI) |
S1-C1-S2 | 105.83 (8)/106.20 (9) | 105.8 (2) | 106.6 (4) | 106.93 (8) | 107.37 (9) | 112 |
C1-S2-C2 | 98.60 (8)/97.80 (9) | 94.7 (2) | 96.1 (5) | 94.6 (1) | 95.04 (9) | 94 |
C1-S1-C3 | 99.74 (8)/99.81 (8) | 99.0 (2) | 97.9 (5) | 98.4 (1) | 97.89 (9) | 92 |
S2-C2-C3 | 106.13 (12)/106.31 (13) | 106.9 (3) | 111.7 (5) | 107.5 (2) | 109.0 (2) | 109 |
C2-C3-S1 | 105.61 (12)/107.96 (13) | 108.3 (4) | 111.4 (5) | 109.7 (2) | 107.2 (1) | 106 |
Simple vinyl (Maignan & Raphael, 1983) or acetylenic (Maignan & Belkasmioui, 1988; Lee et al., 1988) sulfoxides are poor dienophiles, and show low levels of diastereocontrol, thereby limiting their synthetic use. The alkylation of a simple vinyl sulfoxide, however, gives rise to a much more reactive dienophile (Kagan & Ronan, 1991, 1992). Simple vinyl sulfoxides can also be made more reactive by the introduction of an additional electron-withdrawing group. 1,1-Bis(p-tolylsulfinyl)ethene (Arai et al., 1986) facilitates a highly stereoselective reaction with cyclopentadiene under Lewis acid catalysis in a Diels–Alder reaction.
In recent years, compounds having two geminal sulfones have been shown to be good dienophiles, and their Diels–Alder reactions have attracted considerable attention (Lucchi et al., 1992). The sulfonyl group has versatile functionality in organic synthesis and can be conveniently eliminated, resulting in an alkene (Little & Myong, 1980; Lopez & Carretero, 1991). Moreover, the sulfonyl group may undergo desulfonylation and oxidative desulfonylation with the formation of the corresponding ketones (Leon & Carretero, 1991).
C2-symmetric cyclic alkenyl sulfoxides (Aggarwal et al., 1995) show high selectivity in Diels–Alder reactions. The Diels–Alder adducts may also be converted into bridged unsaturated ketones, for example, norbornenone, which is a useful intermediate for the synthesis of biologically important compounds.
Racemic 2-methoxymethyl-1,3-dithiolane 1,3-dioxide has been shown to be a useful starting material for the preparation of C2-symmetric ketene equivalents (Aggarwal et al., 1998). The title compound, (I), may also be a useful starting material for the preparation of a new sulfone-containing dienophile.
The structure determination of (I) was undertaken in order to understand the effects of the methoxymethyl group and the O atoms on the geometry of the five-membered dithiolane ring, and to compare the results with those found in 1,2,3,4-tetrahydrocarbazole-1-spiro-2'-[1,3]dithiolane, (II) (Hökelek et al., 1994), N-(2-methoxyethyl)-N-{2,3,4,9-tetrahydrospiro- [1H-carbazole-1,2-[1,3]dithiolane]-4-yl}benzenesulfonamide, (III) (Patıret al., 1997), spiro[carbazole-1(2H),2'-[1,3]dithiolan]-4(3H)-one, (IV) (Hökelek et al., 1998), 9-acetonyl-3-ethyldiene-1,2,3,4-tetrahydrospiro[carbazole- 1,2'-[1,3]dithiolan]-4-one, (V) (Hökelek et al., 1999), and (1RS,3RS,αSR)-1,3-dioxo-α-phenyl-1,3-dithiolane-2-methanol, (VI) (Aggarwal et al., 1997).
The title compound, (I) (Fig. 1), consists of a five-membered dithiolane ring with two O atoms bonded to each S atom and a methoxymethyl group attached at the 2-position. The asymmetric unit consists of two molecules. The S atoms of the dithiolane ring have electron-releasing properties, but the O atoms bonded to S have electron-withdrawing properties, thereby influencing bond lengths and angles of the dithiolane ring (Table 1). It should be stressed, however, that the values are almost identical in both molecules.
Some significant changes in the geometry of the dithiolane ring are evident when a few bond angles are compared with the values found in compounds (II)–(VI) (Table 2).
The dithiolane rings are, of course, not planar. In each of the two molecules of the asymmetric unit, the conformation is half-chair. In one molecule, considering only the ring atoms and atoms O1–O4, there is a local twofold rotation axis passing through C1 and the mid-point of C2—C3.
The structure reveals a number of short contacts (Å): O2i···H11(C1) 2.24 (2), O1ii···H21(C2) 2.28 (3), O1'iii···H31(C3) 2.45 (3), O1iii···H32(C3) 2.46 (3), O4'iv···H22'(C2') 2.47 (3), O2'v···H11'(C1') 2.51 (3) and O2vi···H31'(C3') 2.54 (3) [symmetry codes: (i) −x, −y + 2,- z + 1; (ii) x + 1, y, z; (iii) −x, −y + 1, −z + 1; (iv) −x − 2, −y, −z + 2; (v) −x − 1, −y, −z + 2; (vi) −x − 1, −y + 1, −z + 1]. These interactions play a role in determining the molecular conformation of each molecule.