Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S0108270105000557/sq1188sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270105000557/sq1188Isup2.hkl | |
Structure factor file (CIF format) https://doi.org/10.1107/S0108270105000557/sq1188IIsup3.hkl |
CCDC references: 268096; 268097
A solution of lithium diisopropylamide was prepared by dissolving diisopropylamine (8.3 g, 80 mmol) in anhydrous tetrahydrofuran (thf, 100 ml), cooling the solution to 233 K in a dry ice-acetone bath, and adding n-butyllithium (80 mmol, 72.8 ml, 1.1 M in hexane) under an atmosphere of argon. A solution of 3-methylenecyclohexanecarboxylic acid (5.68 g, 40 mmol) in cold thf (233 K, 30 ml) was injected via cannula and reacted for 40 min at 233 K. The reaction mixture was heated to 323 K for an additional 2 h. The resulting bright-yellow solution was cooled (233 K), and 2,2-dimethyl-1,3-dioxan-5-one (5.20 g, 40 mmol) was added dropwise (via syringe pump) over a period of 2 h. After completion of the addition, the mixture was stirred for 2.5 h at 233 K. The quenched reaction mixture was treated with aqueous HCl solution (5%, 200 ml), and the aqueous phase was extracted with ether (150 ml). The organic phase was washed with water, dried over MgSO4, concentrated and purified on silica gel to give (V) (yield 9.61 g, 35.6 mmol, 89%). To a solution of (V) (8.10 g, 30 mmol) in acetone (130 ml) was added dropwise diisopropylamine (4.6 ml, 30 mmol). The resulting salt was concentrated in vacuo and dissolved in anhydrous dichloromethane (150 ml). Iodine (7.8 g, 30 mmol) in dichloromethane (150 ml) was injected under argon and reacted for 48 h at room temperature. The quenched reaction mixture was shaken with aqueous sodium thiosulfate (10%, 30 ml), dried, and evaporated in vacuo. The residue was purified by chromatography on silica gel to afford an unstable solid identified as the iodolactone (VI) (yield 10.8 g, 27.3 mmol, 91%). Iodolactone (VI) (10 g, 25.3 mmol) was dissolved in thf (80 ml). To the cold solution was added potassium hydroxide (2.13 g, 38 mmol) dissolved in water (130 ml). After completion of the addition, the mixture was stirred for 30 min at 298 K. The quenched reaction mixture was treated with aqueous HCl solution (5%, 100 ml) and water (100 ml). The organic phase was dried and concentrated to give the unstable epoxide (VII) (yield 6.95 g, 24.3 mmol, 96%). The white solid so obtained was dried by passing argon through and transferred under anhydrous atmosphere. A solution of this solid in dichloromethane (100 ml) was cooled (195 K) under argon and treated with p-toluenesulfonic acid (3 mg) in dichloromethane (60 ml). The reaction was stirred for 30 min at room temperature. The quenched reaction was washed with water (60 ml), dried over MgSO4 and concentrated in vacuo. The residue was purified by chromatography on silica gel (5–15% ethyl acetate in n-hexane) to give dihydroxylactones (I) (2.72 g, 11.93 mmol) and (II) (2.80 g, 12.28 mmol). Single crystals of (I) and (II), suitable for X-ray analysis, were grown at room temperature from damp carbon tetrachloride/n-hexane.
All H atoms were located in difference Fourier maps and subsequently allowed to refine as riding on their respective C and O atoms C—H = 0.97 Å and O—H = 0.82 Å. The O atoms, except O6 in (II), have elongated displacement ellipsoids; however, split peaks for these atoms were not observed and consequently a disorder model was not used in the refinement.
For both compounds, data collection: Collect (Nonius, 2000); cell refinement: HKL SCALEPACK (Otwinowski & Minor, 1997); data reduction: HKL DENZO (Otwinowski & Minor, 1997) and SCALEPACK; program(s) used to solve structure: Sir97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: Xtal3.6 (Hall et al., 1999); software used to prepare material for publication: SHELXL97, WinGX (Farrugia, 1999) and PLATON (Spek, 2003).
C11H16O5 | F(000) = 488 |
Mr = 228.24 | Dx = 1.440 Mg m−3 |
Monoclinic, P21/c | Melting point = 464–465 K |
Hall symbol: -P 2ybc | Mo Kα radiation, λ = 0.71073 Å |
a = 8.067 (3) Å | Cell parameters from 2404 reflections |
b = 11.029 (3) Å | θ = 6.4–27.6° |
c = 12.769 (4) Å | µ = 0.11 mm−1 |
β = 112.12 (2)° | T = 295 K |
V = 1052.4 (6) Å3 | Prism, colourless |
Z = 4 | 0.50 × 0.20 × 0.15 mm |
Nonius KappaCCD diffractometer | 1989 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.043 |
Horizonally mounted graphite crystal monochromator | θmax = 27.6°, θmin = 6.4° |
Detector resolution: 9 pixels mm-1 | h = −8→10 |
ϕ and ω scans | k = −14→13 |
8698 measured reflections | l = −16→14 |
2404 independent reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.045 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.121 | H-atom parameters constrained |
S = 1.08 | w = 1/[σ2(Fo2) + (0.0513P)2 + 0.3909P] where P = (Fo2 + 2Fc2)/3 |
2404 reflections | (Δ/σ)max < 0.001 |
147 parameters | Δρmax = 0.29 e Å−3 |
0 restraints | Δρmin = −0.19 e Å−3 |
C11H16O5 | V = 1052.4 (6) Å3 |
Mr = 228.24 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 8.067 (3) Å | µ = 0.11 mm−1 |
b = 11.029 (3) Å | T = 295 K |
c = 12.769 (4) Å | 0.50 × 0.20 × 0.15 mm |
β = 112.12 (2)° |
Nonius KappaCCD diffractometer | 1989 reflections with I > 2σ(I) |
8698 measured reflections | Rint = 0.043 |
2404 independent reflections |
R[F2 > 2σ(F2)] = 0.045 | 0 restraints |
wR(F2) = 0.121 | H-atom parameters constrained |
S = 1.08 | Δρmax = 0.29 e Å−3 |
2404 reflections | Δρmin = −0.19 e Å−3 |
147 parameters |
Experimental. Compound (I): m.p. 464–465 K, 1H NMR (300 MHz, MeOD) δ 4.47 (d, J = 6.9 Hz, 1H), 4.19 (d, J = 6.9 Hz, 1H), 3.65 (d, J = 1.6 Hz, 1H), 3.64 (d, J = 1.6 Hz, 1H), 3.56 (d, J = 8.4 Hz, 2H), 1.96 (m, 2H), 1.88 (m, 2H), 1.75 (dd, J1 = 12.6, J2 = 8.4 Hz, 1H), 1.59 (m, 3H); IR (KBr) νmax 3356, 2923, 1762, 1652, 1541, 1458, 1261, 1016 cm−1. |
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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.19499 (17) | 0.25627 (13) | 0.52610 (12) | 0.0293 (3) | |
C2 | 0.02223 (19) | 0.32064 (17) | 0.50826 (14) | 0.0399 (4) | |
O3 | −0.03678 (15) | 0.37961 (11) | 0.40926 (11) | 0.0468 (3) | |
C4 | 0.0698 (2) | 0.34605 (15) | 0.34401 (13) | 0.0374 (4) | |
H4A | 0.1515 | 0.4109 | 0.3447 | 0.045* | |
H4B | −0.0064 | 0.3284 | 0.2663 | 0.045* | |
C5 | 0.17333 (17) | 0.23242 (13) | 0.40268 (11) | 0.0289 (3) | |
O6 | 0.33537 (13) | 0.21246 (11) | 0.38593 (8) | 0.0367 (3) | |
C7 | 0.48616 (19) | 0.28543 (17) | 0.44979 (13) | 0.0378 (4) | |
H7A | 0.4701 | 0.3660 | 0.4170 | 0.045* | |
H7B | 0.5927 | 0.2509 | 0.4437 | 0.045* | |
C8 | 0.51530 (17) | 0.29630 (14) | 0.57468 (12) | 0.0314 (3) | |
C9 | 0.5629 (2) | 0.17757 (17) | 0.64103 (14) | 0.0437 (4) | |
H9A | 0.6038 | 0.1960 | 0.7211 | 0.052* | |
H9B | 0.6617 | 0.1399 | 0.6274 | 0.052* | |
C10 | 0.4091 (2) | 0.08647 (17) | 0.61151 (17) | 0.0504 (5) | |
H10A | 0.3933 | 0.0480 | 0.5401 | 0.061* | |
H10B | 0.4402 | 0.0239 | 0.6691 | 0.061* | |
C11 | 0.2327 (2) | 0.14534 (17) | 0.60252 (14) | 0.0436 (4) | |
H11A | 0.1359 | 0.0874 | 0.5720 | 0.052* | |
H11B | 0.2393 | 0.1691 | 0.6771 | 0.052* | |
C12 | 0.34662 (18) | 0.34944 (14) | 0.58092 (12) | 0.0313 (3) | |
H12A | 0.3180 | 0.4259 | 0.5405 | 0.038* | |
H12B | 0.3621 | 0.3638 | 0.6590 | 0.038* | |
O13 | −0.05468 (16) | 0.32653 (16) | 0.57281 (12) | 0.0647 (4) | |
C14 | 0.0643 (2) | 0.11853 (15) | 0.35234 (14) | 0.0397 (4) | |
H14A | 0.0513 | 0.1100 | 0.2740 | 0.048* | |
H14B | 0.1268 | 0.0477 | 0.3934 | 0.048* | |
O15 | −0.10710 (15) | 0.12568 (12) | 0.35859 (11) | 0.0490 (3) | |
H15 | −0.1841 | 0.1268 | 0.2945 | 0.059* | |
O16 | 0.65711 (13) | 0.38294 (11) | 0.62416 (10) | 0.0415 (3) | |
H16 | 0.7384 | 0.3694 | 0.6020 | 0.050* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0197 (6) | 0.0391 (8) | 0.0295 (7) | −0.0037 (5) | 0.0096 (5) | −0.0013 (6) |
C2 | 0.0213 (7) | 0.0535 (10) | 0.0444 (8) | −0.0055 (6) | 0.0117 (6) | −0.0115 (7) |
O3 | 0.0281 (6) | 0.0492 (7) | 0.0574 (7) | 0.0084 (5) | 0.0094 (5) | −0.0020 (6) |
C4 | 0.0300 (7) | 0.0394 (8) | 0.0367 (8) | 0.0001 (6) | 0.0057 (6) | 0.0060 (6) |
C5 | 0.0211 (6) | 0.0360 (7) | 0.0270 (6) | −0.0024 (5) | 0.0062 (5) | −0.0003 (5) |
O6 | 0.0255 (5) | 0.0519 (7) | 0.0322 (5) | −0.0025 (5) | 0.0104 (4) | −0.0104 (5) |
C7 | 0.0237 (7) | 0.0560 (10) | 0.0359 (8) | −0.0059 (6) | 0.0136 (6) | −0.0057 (7) |
C8 | 0.0185 (6) | 0.0416 (8) | 0.0327 (7) | −0.0043 (5) | 0.0079 (5) | −0.0055 (6) |
C9 | 0.0278 (7) | 0.0527 (10) | 0.0418 (8) | 0.0036 (7) | 0.0029 (6) | 0.0041 (7) |
C10 | 0.0422 (9) | 0.0441 (10) | 0.0521 (10) | 0.0014 (7) | 0.0030 (8) | 0.0160 (8) |
C11 | 0.0364 (8) | 0.0558 (10) | 0.0352 (8) | −0.0116 (7) | 0.0096 (7) | 0.0100 (7) |
C12 | 0.0209 (6) | 0.0403 (8) | 0.0318 (7) | −0.0033 (5) | 0.0091 (5) | −0.0070 (6) |
O13 | 0.0301 (6) | 0.1098 (12) | 0.0622 (8) | −0.0057 (7) | 0.0266 (6) | −0.0222 (8) |
C14 | 0.0319 (8) | 0.0399 (9) | 0.0384 (8) | −0.0056 (6) | 0.0030 (6) | −0.0045 (7) |
O15 | 0.0303 (6) | 0.0576 (8) | 0.0500 (7) | −0.0141 (5) | 0.0048 (5) | 0.0025 (6) |
O16 | 0.0200 (5) | 0.0550 (7) | 0.0473 (6) | −0.0089 (5) | 0.0100 (5) | −0.0132 (5) |
C1—C2 | 1.503 (2) | C8—C12 | 1.5110 (19) |
C1—C11 | 1.523 (2) | C8—C9 | 1.528 (2) |
C1—C5 | 1.541 (2) | C9—C10 | 1.529 (3) |
C1—C12 | 1.5483 (19) | C9—H9A | 0.9700 |
C2—O13 | 1.206 (2) | C9—H9B | 0.9700 |
C2—O3 | 1.340 (2) | C10—C11 | 1.529 (3) |
O3—C4 | 1.452 (2) | C10—H10A | 0.9700 |
C4—C5 | 1.536 (2) | C10—H10B | 0.9700 |
C4—H4A | 0.9700 | C11—H11A | 0.9700 |
C4—H4B | 0.9700 | C11—H11B | 0.9700 |
C5—O6 | 1.4190 (17) | C12—H12A | 0.9700 |
C5—C14 | 1.529 (2) | C12—H12B | 0.9700 |
O6—C7 | 1.4302 (19) | C14—O15 | 1.417 (2) |
C7—C8 | 1.527 (2) | C14—H14A | 0.9700 |
C7—H7A | 0.9700 | C14—H14B | 0.9700 |
C7—H7B | 0.9700 | O15—H15 | 0.8200 |
C8—O16 | 1.4410 (17) | O16—H16 | 0.8200 |
C2—C1—C11 | 115.26 (13) | C7—C8—C9 | 114.81 (14) |
C2—C1—C5 | 100.60 (12) | C8—C9—C10 | 114.52 (13) |
C11—C1—C5 | 115.88 (13) | C8—C9—H9A | 108.6 |
C2—C1—C12 | 106.54 (12) | C10—C9—H9A | 108.6 |
C11—C1—C12 | 108.08 (12) | C8—C9—H9B | 108.6 |
C5—C1—C12 | 109.98 (11) | C10—C9—H9B | 108.6 |
O13—C2—O3 | 121.84 (16) | H9A—C9—H9B | 107.6 |
O13—C2—C1 | 127.47 (17) | C11—C10—C9 | 112.67 (16) |
O3—C2—C1 | 110.62 (13) | C11—C10—H10A | 109.1 |
C2—O3—C4 | 109.93 (12) | C9—C10—H10A | 109.1 |
O3—C4—C5 | 105.00 (12) | C11—C10—H10B | 109.1 |
O3—C4—H4A | 110.7 | C9—C10—H10B | 109.1 |
C5—C4—H4A | 110.7 | H10A—C10—H10B | 107.8 |
O3—C4—H4B | 110.7 | C1—C11—C10 | 110.19 (13) |
C5—C4—H4B | 110.7 | C1—C11—H11A | 109.6 |
H4A—C4—H4B | 108.8 | C10—C11—H11A | 109.6 |
O6—C5—C14 | 103.07 (12) | C1—C11—H11B | 109.6 |
O6—C5—C4 | 114.57 (12) | C10—C11—H11B | 109.6 |
C14—C5—C4 | 110.12 (12) | H11A—C11—H11B | 108.1 |
O6—C5—C1 | 115.11 (11) | C8—C12—C1 | 107.02 (12) |
C14—C5—C1 | 113.31 (12) | C8—C12—H12A | 110.3 |
C4—C5—C1 | 101.00 (12) | C1—C12—H12A | 110.3 |
C5—O6—C7 | 117.45 (11) | C8—C12—H12B | 110.3 |
O6—C7—C8 | 113.77 (12) | C1—C12—H12B | 110.3 |
O6—C7—H7A | 108.8 | H12A—C12—H12B | 108.6 |
C8—C7—H7A | 108.8 | O15—C14—C5 | 110.48 (13) |
O6—C7—H7B | 108.8 | O15—C14—H14A | 109.6 |
C8—C7—H7B | 108.8 | C5—C14—H14A | 109.6 |
H7A—C7—H7B | 107.7 | O15—C14—H14B | 109.6 |
O16—C8—C12 | 107.56 (12) | C5—C14—H14B | 109.6 |
O16—C8—C7 | 107.14 (12) | H14A—C14—H14B | 108.1 |
C12—C8—C7 | 107.34 (12) | C14—O15—H15 | 109.5 |
O16—C8—C9 | 109.43 (12) | C8—O16—H16 | 109.5 |
C12—C8—C9 | 110.28 (12) | ||
C11—C1—C2—O13 | 29.5 (2) | C7—C8—C12—C1 | 64.3 (2) |
C5—C1—C2—O13 | 154.96 (17) | O6—C7—C8—C12 | −58.1 (2) |
C12—C1—C2—O13 | −90.3 (2) | C5—O6—C7—C8 | 45.7 (2) |
C11—C1—C2—O3 | −153.72 (14) | C1—C5—O6—C7 | −39.6 (2) |
C5—C1—C2—O3 | −28.3 (2) | O6—C7—C8—O16 | −173.40 (12) |
C12—C1—C2—O3 | 86.4 (2) | O6—C7—C8—C9 | 64.86 (17) |
O13—C2—O3—C4 | −173.92 (16) | O16—C8—C9—C10 | 168.94 (14) |
C1—C2—O3—C4 | 9.1 (2) | C12—C8—C9—C10 | 50.8 (2) |
C2—O3—C4—C5 | 14.4 (2) | C9—C8—C12—C1 | −61.5 (2) |
O3—C4—C5—O6 | −155.01 (12) | C11—C1—C12—C8 | 68.4 (2) |
O3—C4—C5—C14 | 89.38 (14) | C12—C1—C11—C10 | −62.4 (2) |
O3—C4—C5—C1 | −30.7 (1) | C9—C10—C11—C1 | 50.1 (2) |
C2—C1—C5—C4 | 34.3 (1) | C7—C8—C9—C10 | −70.57 (18) |
C2—C1—C5—O6 | 158.23 (12) | C8—C9—C10—C11 | −44.6 (2) |
C11—C1—C5—O6 | −76.78 (16) | C2—C1—C11—C10 | 178.61 (14) |
C2—C1—C5—C14 | −83.48 (15) | C5—C1—C11—C10 | 61.54 (17) |
C11—C1—C5—C14 | 41.51 (17) | O16—C8—C12—C1 | 179.27 (11) |
C12—C1—C5—C14 | 164.42 (12) | C2—C1—C12—C8 | −167.22 (12) |
C11—C1—C5—C4 | 159.24 (12) | O6—C5—C14—O15 | −177.91 (12) |
C12—C1—C5—C4 | −77.84 (13) | C4—C5—C14—O15 | −55.25 (16) |
C14—C5—O6—C7 | −163.47 (13) | C1—C5—C14—O15 | 57.0 (2) |
C4—C5—O6—C7 | 76.89 (16) | O16—C8—C14—O15 | −98.9 (3) |
C12—C1—C5—O6 | 46.1 (2) | O16—C8—C5—C14 | 162.3 (2) |
C5—C1—C12—C8 | −59.0 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O15—H15···O16i | 0.82 | 2.07 | 2.881 (2) | 170 |
O16—H16···O13ii | 0.82 | 1.90 | 2.715 (2) | 171 |
C14—H14A···O13iii | 0.97 | 2.48 | 3.384 (2) | 154 |
C11—H11A···O15iv | 0.97 | 2.55 | 3.254 (2) | 129 |
Symmetry codes: (i) x−1, −y+1/2, z−1/2; (ii) x+1, y, z; (iii) x, −y+1/2, z−1/2; (iv) −x, −y, −z+1. |
C11H16O5 | Dx = 1.382 Mg m−3 |
Mr = 228.24 | Melting point = 452–453 K |
Orthorhombic, Pbca | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ac 2ab | Cell parameters from 2511 reflections |
a = 7.8896 (6) Å | θ = 5.2–27.5° |
b = 12.7281 (10) Å | µ = 0.11 mm−1 |
c = 21.8425 (18) Å | T = 295 K |
V = 2193.4 (3) Å3 | Plate, colourless |
Z = 8 | 0.50 × 0.43 × 0.15 mm |
F(000) = 976 |
Nonius KappaCCD diffractometer | 1623 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.065 |
Horizonally mounted graphite crystal monochromator | θmax = 27.5°, θmin = 5.2° |
Detector resolution: 9 pixels mm-1 | h = −10→5 |
ϕ and ω scans | k = −16→15 |
10431 measured reflections | l = −23→28 |
2511 independent reflections |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.053 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.132 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.0653P)2 + 0.1829P] where P = (Fo2 + 2Fc2)/3 |
2511 reflections | (Δ/σ)max = 0.001 |
147 parameters | Δρmax = 0.24 e Å−3 |
0 restraints | Δρmin = −0.20 e Å−3 |
C11H16O5 | V = 2193.4 (3) Å3 |
Mr = 228.24 | Z = 8 |
Orthorhombic, Pbca | Mo Kα radiation |
a = 7.8896 (6) Å | µ = 0.11 mm−1 |
b = 12.7281 (10) Å | T = 295 K |
c = 21.8425 (18) Å | 0.50 × 0.43 × 0.15 mm |
Nonius KappaCCD diffractometer | 1623 reflections with I > 2σ(I) |
10431 measured reflections | Rint = 0.065 |
2511 independent reflections |
R[F2 > 2σ(F2)] = 0.053 | 0 restraints |
wR(F2) = 0.132 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.24 e Å−3 |
2511 reflections | Δρmin = −0.20 e Å−3 |
147 parameters |
Experimental. Compound (II): m.p. 452–453 K; 1H NMR (300 MHz, MeOD) δ 4.37 (d, J = 9.3 Hz, 1H), 4.23 (d, J = 9.3 Hz, 1H), 3.94 (d, J = 11.1 Hz, 1H), 3.78 (d, J = 11.1 Hz, 1H), 3.60 (d, J =12.0 Hz, 1H), 3.47 (d, J = 12.0 Hz, 1H), 2.60 (d, J = 11.1 Hz, 1H), 1.94 (m, 4H), 1.70 (d, J = 11.1 Hz, 1H), 1.57 (m, 2H); IR (KBr) νmax 3387, 2952, 2875, 1765, 1655, 1460, 1373, 1136, 1099, 1016 cm−1. |
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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.5033 (2) | 0.13429 (14) | 0.66915 (8) | 0.0356 (4) | |
C2 | 0.4967 (3) | 0.22708 (18) | 0.71149 (9) | 0.0536 (6) | |
O3 | 0.4889 (2) | 0.31723 (11) | 0.67800 (7) | 0.0634 (5) | |
C4 | 0.4786 (2) | 0.29380 (14) | 0.61319 (9) | 0.0430 (5) | |
H4A | 0.5873 | 0.3052 | 0.5935 | 0.052* | |
H4B | 0.3945 | 0.3379 | 0.5935 | 0.052* | |
C5 | 0.4271 (2) | 0.17704 (12) | 0.60919 (7) | 0.0283 (4) | |
O6 | 0.51249 (13) | 0.12228 (9) | 0.56070 (5) | 0.0301 (3) | |
C7 | 0.6497 (2) | 0.06012 (14) | 0.58743 (8) | 0.0339 (4) | |
C8 | 0.5880 (3) | −0.05145 (15) | 0.60142 (9) | 0.0468 (5) | |
H8A | 0.5612 | −0.0867 | 0.5633 | 0.056* | |
H8B | 0.6786 | −0.0903 | 0.6211 | 0.056* | |
C9 | 0.4317 (3) | −0.05291 (14) | 0.64275 (9) | 0.0486 (5) | |
H9A | 0.4250 | −0.1211 | 0.6624 | 0.058* | |
H9B | 0.3317 | −0.0451 | 0.6173 | 0.058* | |
C10 | 0.4277 (3) | 0.03199 (15) | 0.69244 (8) | 0.0455 (5) | |
H10A | 0.3115 | 0.0439 | 0.7051 | 0.055* | |
H10B | 0.4913 | 0.0081 | 0.7278 | 0.055* | |
C11 | 0.6860 (2) | 0.11471 (15) | 0.64744 (8) | 0.0389 (5) | |
H11A | 0.7477 | 0.1798 | 0.6415 | 0.047* | |
H11B | 0.7479 | 0.0698 | 0.6755 | 0.047* | |
O12 | 0.5005 (2) | 0.22760 (16) | 0.76625 (7) | 0.0842 (6) | |
C13 | 0.2373 (2) | 0.16744 (14) | 0.60216 (8) | 0.0350 (4) | |
H13A | 0.2054 | 0.0939 | 0.6003 | 0.042* | |
H13B | 0.1812 | 0.1989 | 0.6372 | 0.042* | |
O14 | 0.18590 (16) | 0.21894 (12) | 0.54787 (6) | 0.0529 (4) | |
H14 | 0.0872 | 0.2037 | 0.5402 | 0.063* | |
C15 | 0.7926 (2) | 0.06042 (18) | 0.54133 (9) | 0.0509 (6) | |
H15A | 0.8814 | 0.0136 | 0.5554 | 0.061* | |
H15B | 0.7508 | 0.0335 | 0.5026 | 0.061* | |
O16 | 0.86205 (16) | 0.16121 (13) | 0.53185 (7) | 0.0598 (5) | |
H16 | 0.8014 | 0.1943 | 0.5082 | 0.072* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0398 (10) | 0.0414 (10) | 0.0256 (9) | −0.0046 (8) | −0.0040 (7) | −0.0016 (7) |
C2 | 0.0609 (15) | 0.0601 (14) | 0.0399 (12) | −0.0098 (11) | −0.0059 (9) | −0.0161 (10) |
O3 | 0.0845 (13) | 0.0446 (9) | 0.0610 (10) | −0.0064 (8) | −0.0068 (8) | −0.0232 (7) |
C4 | 0.0459 (12) | 0.0323 (10) | 0.0508 (12) | −0.0056 (8) | −0.0030 (9) | −0.0021 (9) |
C5 | 0.0277 (9) | 0.0287 (9) | 0.0285 (9) | −0.0019 (7) | 0.0002 (7) | −0.0020 (7) |
O6 | 0.0254 (6) | 0.0379 (7) | 0.0269 (6) | 0.0031 (5) | −0.0024 (5) | −0.0008 (5) |
C7 | 0.0277 (9) | 0.0391 (10) | 0.0348 (10) | 0.0045 (8) | −0.0059 (7) | 0.0021 (8) |
C8 | 0.0501 (12) | 0.0354 (10) | 0.0548 (12) | 0.0073 (9) | −0.0039 (10) | 0.0002 (9) |
C9 | 0.0570 (13) | 0.0317 (10) | 0.0570 (13) | −0.0082 (10) | −0.0047 (10) | 0.0133 (9) |
C10 | 0.0490 (11) | 0.0532 (12) | 0.0342 (10) | −0.0050 (10) | −0.0014 (9) | 0.0155 (9) |
C11 | 0.0337 (10) | 0.0452 (11) | 0.0377 (10) | −0.0029 (8) | −0.0116 (8) | 0.0058 (8) |
O12 | 0.1108 (16) | 0.1045 (15) | 0.0373 (10) | −0.0160 (12) | −0.0051 (9) | −0.0285 (9) |
C13 | 0.0299 (9) | 0.0383 (10) | 0.0367 (9) | −0.0015 (8) | 0.0035 (7) | 0.0060 (8) |
O14 | 0.0255 (7) | 0.0724 (10) | 0.0607 (9) | −0.0073 (7) | −0.0075 (6) | 0.0316 (7) |
C15 | 0.0321 (11) | 0.0678 (15) | 0.0527 (12) | 0.0123 (10) | 0.0017 (9) | 0.0074 (11) |
O16 | 0.0266 (7) | 0.0866 (12) | 0.0663 (10) | −0.0027 (7) | −0.0051 (6) | 0.0351 (8) |
C1—C2 | 1.501 (3) | C8—H8A | 0.9700 |
C1—C10 | 1.520 (2) | C8—H8B | 0.9700 |
C1—C11 | 1.538 (2) | C9—C10 | 1.532 (3) |
C1—C5 | 1.540 (2) | C9—H9A | 0.9700 |
C2—O12 | 1.196 (2) | C9—H9B | 0.9700 |
C2—O3 | 1.362 (3) | C10—H10A | 0.9700 |
O3—C4 | 1.449 (2) | C10—H10B | 0.9700 |
C4—C5 | 1.543 (2) | C11—H11A | 0.9700 |
C4—H4A | 0.9700 | C11—H11B | 0.9700 |
C4—H4B | 0.9700 | C13—O14 | 1.414 (2) |
C5—O6 | 1.4357 (19) | C13—H13A | 0.9700 |
C5—C13 | 1.511 (2) | C13—H13B | 0.9700 |
O6—C7 | 1.4624 (19) | O14—H14 | 0.8200 |
C7—C11 | 1.511 (2) | C15—O16 | 1.410 (3) |
C7—C15 | 1.512 (3) | C15—H15A | 0.9700 |
C7—C8 | 1.532 (3) | C15—H15B | 0.9700 |
C8—C9 | 1.528 (3) | O16—H16 | 0.8200 |
C2—C1—C10 | 117.02 (16) | H8A—C8—H8B | 107.8 |
C2—C1—C11 | 110.50 (15) | C8—C9—C10 | 115.25 (16) |
C10—C1—C11 | 109.39 (16) | C8—C9—H9A | 108.5 |
C2—C1—C5 | 103.44 (15) | C10—C9—H9A | 108.5 |
C10—C1—C5 | 115.72 (15) | C8—C9—H9B | 108.5 |
C11—C1—C5 | 99.26 (13) | C10—C9—H9B | 108.5 |
O12—C2—O3 | 122.2 (2) | H9A—C9—H9B | 107.5 |
O12—C2—C1 | 128.3 (2) | C1—C10—C9 | 111.06 (14) |
O3—C2—C1 | 109.47 (17) | C1—C10—H10A | 109.4 |
C2—O3—C4 | 110.72 (14) | C9—C10—H10A | 109.4 |
O3—C4—C5 | 105.56 (15) | C1—C10—H10B | 109.4 |
O3—C4—H4A | 110.6 | C9—C10—H10B | 109.4 |
C5—C4—H4A | 110.6 | H10A—C10—H10B | 108.0 |
O3—C4—H4B | 110.6 | C7—C11—C1 | 99.45 (13) |
C5—C4—H4B | 110.6 | C7—C11—H11A | 111.9 |
H4A—C4—H4B | 108.8 | C1—C11—H11A | 111.9 |
O6—C5—C13 | 110.54 (13) | C7—C11—H11B | 111.9 |
O6—C5—C1 | 105.83 (13) | C1—C11—H11B | 111.9 |
C13—C5—C1 | 116.42 (14) | H11A—C11—H11B | 109.6 |
O6—C5—C4 | 112.69 (13) | O14—C13—C5 | 109.38 (13) |
C13—C5—C4 | 110.16 (14) | O14—C13—H13A | 109.8 |
C1—C5—C4 | 100.91 (13) | C5—C13—H13A | 109.8 |
C5—O6—C7 | 108.37 (12) | O14—C13—H13B | 109.8 |
O6—C7—C11 | 103.77 (13) | C5—C13—H13B | 109.8 |
O6—C7—C15 | 106.55 (13) | H13A—C13—H13B | 108.2 |
C11—C7—C15 | 115.79 (15) | C13—O14—H14 | 109.5 |
O6—C7—C8 | 110.24 (14) | O16—C15—C7 | 112.94 (17) |
C11—C7—C8 | 108.27 (15) | O16—C15—H15A | 109.0 |
C15—C7—C8 | 111.85 (16) | C7—C15—H15A | 109.0 |
C9—C8—C7 | 112.68 (16) | O16—C15—H15B | 109.0 |
C9—C8—H8A | 109.1 | C7—C15—H15B | 109.0 |
C7—C8—H8A | 109.1 | H15A—C15—H15B | 107.8 |
C9—C8—H8B | 109.1 | C15—O16—H16 | 109.5 |
C7—C8—H8B | 109.1 | ||
C10—C1—C2—O12 | 30.7 (3) | C13—C5—O6—C7 | −134.25 (14) |
C11—C1—C2—O12 | −95.3 (3) | C4—C5—O6—C7 | 102.00 (15) |
C5—C1—C2—O12 | 159.2 (2) | C5—O6—C7—C15 | −145.57 (15) |
C10—C1—C2—O3 | −150.66 (18) | C5—O6—C7—C8 | 92.87 (16) |
C11—C1—C2—O3 | 83.3 (2) | O6—C7—C8—C9 | −55.7 (2) |
C5—C1—C2—O3 | −22.1 (2) | C11—C7—C8—C9 | 57.2 (2) |
O12—C2—O3—C4 | −177.6 (2) | C8—C7—C11—C1 | −73.9 (2) |
C1—C2—O3—C4 | 3.6 (2) | C10—C1—C11—C7 | 75.5 (2) |
C2—O3—C4—C5 | 16.5 (2) | C11—C1—C10—C9 | −57.6 (2) |
O3—C4—C5—C1 | −28.6 (2) | C8—C9—C10—C1 | 36.6 (2) |
C2—C1—C5—C4 | 30.0 (2) | C15—C7—C8—C9 | −174.05 (16) |
C2—C1—C5—O6 | 147.54 (14) | C7—C8—C9—C10 | −36.5 (2) |
C10—C1—C5—O6 | −83.15 (17) | C2—C1—C10—C9 | 175.77 (17) |
C11—C1—C5—O6 | 33.7 (2) | C5—C1—C10—C9 | 53.4 (2) |
C5—C1—C11—C7 | −46.1 (2) | C15—C7—C11—C1 | 159.65 (15) |
O6—C7—C11—C1 | 43.3 (2) | C2—C1—C11—C7 | −154.25 (16) |
C5—O6—C7—C11 | −22.9 (2) | O6—C5—C13—O14 | −64.83 (18) |
C1—C5—O6—C7 | −7.4 (2) | C1—C5—C13—O14 | 174.4 (1) |
C2—C1—C5—C13 | −89.23 (18) | C4—C5—C13—O14 | 60.36 (18) |
C10—C1—C5—C13 | 40.1 (2) | O6—C7—C15—O16 | 64.9 (2) |
C11—C1—C5—C13 | 156.95 (14) | C11—C7—C15—O16 | −49.9 (2) |
C10—C1—C5—C4 | 159.27 (15) | C8—C7—C15—O16 | −174.57 (15) |
C11—C1—C5—C4 | −83.86 (16) | C15—C7—C5—C13 | 113.0 (2) |
O3—C4—C5—O6 | −141.04 (14) | O16—C15—C13—O14 | 62.2 (2) |
O3—C4—C5—C13 | 95.01 (16) |
D—H···A | D—H | H···A | D···A | D—H···A |
O14—H14···O16i | 0.82 | 1.87 | 2.682 (2) | 173 |
O16—H16···O14ii | 0.82 | 1.88 | 2.700 (2) | 173 |
C9—H9A···O12iii | 0.97 | 2.55 | 3.470 (2) | 159 |
C13—H13B···O12iv | 0.97 | 2.57 | 3.512 (2) | 163 |
Symmetry codes: (i) x−1, y, z; (ii) x+1/2, −y+1/2, −z+1; (iii) −x+1, y−1/2, −z+3/2; (iv) x−1/2, y, −z+3/2. |
Experimental details
(I) | (II) | |
Crystal data | ||
Chemical formula | C11H16O5 | C11H16O5 |
Mr | 228.24 | 228.24 |
Crystal system, space group | Monoclinic, P21/c | Orthorhombic, Pbca |
Temperature (K) | 295 | 295 |
a, b, c (Å) | 8.067 (3), 11.029 (3), 12.769 (4) | 7.8896 (6), 12.7281 (10), 21.8425 (18) |
α, β, γ (°) | 90, 112.12 (2), 90 | 90, 90, 90 |
V (Å3) | 1052.4 (6) | 2193.4 (3) |
Z | 4 | 8 |
Radiation type | Mo Kα | Mo Kα |
µ (mm−1) | 0.11 | 0.11 |
Crystal size (mm) | 0.50 × 0.20 × 0.15 | 0.50 × 0.43 × 0.15 |
Data collection | ||
Diffractometer | Nonius KappaCCD diffractometer | Nonius KappaCCD diffractometer |
Absorption correction | – | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 8698, 2404, 1989 | 10431, 2511, 1623 |
Rint | 0.043 | 0.065 |
(sin θ/λ)max (Å−1) | 0.652 | 0.650 |
Refinement | ||
R[F2 > 2σ(F2)], wR(F2), S | 0.045, 0.121, 1.08 | 0.053, 0.132, 1.03 |
No. of reflections | 2404 | 2511 |
No. of parameters | 147 | 147 |
H-atom treatment | H-atom parameters constrained | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.29, −0.19 | 0.24, −0.20 |
Computer programs: Collect (Nonius, 2000), HKL SCALEPACK (Otwinowski & Minor, 1997), HKL DENZO (Otwinowski & Minor, 1997) and SCALEPACK, Sir97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 1997), Xtal3.6 (Hall et al., 1999), SHELXL97, WinGX (Farrugia, 1999) and PLATON (Spek, 2003).
C5—C1—C2—O3 | −28.3 (2) | C1—C5—O6—C7 | −39.6 (2) |
C1—C2—O3—C4 | 9.1 (2) | C12—C8—C9—C10 | 50.8 (2) |
C2—O3—C4—C5 | 14.4 (2) | C9—C8—C12—C1 | −61.5 (2) |
O3—C4—C5—C1 | −30.7 (1) | C11—C1—C12—C8 | 68.4 (2) |
C2—C1—C5—C4 | 34.3 (1) | C12—C1—C11—C10 | −62.4 (2) |
C12—C1—C5—O6 | 46.1 (2) | C9—C10—C11—C1 | 50.1 (2) |
C5—C1—C12—C8 | −59.0 (2) | C8—C9—C10—C11 | −44.6 (2) |
C7—C8—C12—C1 | 64.3 (2) | C1—C5—C14—O15 | 57.0 (2) |
O6—C7—C8—C12 | −58.1 (2) | O16—C8—C14—O15 | −98.9 (3) |
C5—O6—C7—C8 | 45.7 (2) | O16—C8—C5—C14 | 162.3 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O15—H15···O16i | 0.82 | 2.07 | 2.881 (2) | 170 |
O16—H16···O13ii | 0.82 | 1.90 | 2.715 (2) | 171 |
C14—H14A···O13iii | 0.97 | 2.48 | 3.384 (2) | 154 |
C11—H11A···O15iv | 0.97 | 2.55 | 3.254 (2) | 129 |
Symmetry codes: (i) x−1, −y+1/2, z−1/2; (ii) x+1, y, z; (iii) x, −y+1/2, z−1/2; (iv) −x, −y, −z+1. |
C5—C1—C2—O3 | −22.1 (2) | C11—C7—C8—C9 | 57.2 (2) |
C1—C2—O3—C4 | 3.6 (2) | C8—C7—C11—C1 | −73.9 (2) |
C2—O3—C4—C5 | 16.5 (2) | C10—C1—C11—C7 | 75.5 (2) |
O3—C4—C5—C1 | −28.6 (2) | C11—C1—C10—C9 | −57.6 (2) |
C2—C1—C5—C4 | 30.0 (2) | C8—C9—C10—C1 | 36.6 (2) |
C11—C1—C5—O6 | 33.7 (2) | C7—C8—C9—C10 | −36.5 (2) |
C5—C1—C11—C7 | −46.1 (2) | C1—C5—C13—O14 | 174.4 (1) |
O6—C7—C11—C1 | 43.3 (2) | O6—C7—C15—O16 | 64.9 (2) |
C5—O6—C7—C11 | −22.9 (2) | O16—C15—C13—O14 | 62.2 (2) |
C1—C5—O6—C7 | −7.4 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O14—H14···O16i | 0.82 | 1.87 | 2.682 (2) | 173 |
O16—H16···O14ii | 0.82 | 1.88 | 2.700 (2) | 173 |
C9—H9A···O12iii | 0.97 | 2.55 | 3.470 (2) | 159 |
C13—H13B···O12iv | 0.97 | 2.57 | 3.512 (2) | 163 |
Symmetry codes: (i) x−1, y, z; (ii) x+1/2, −y+1/2, −z+1; (iii) −x+1, y−1/2, −z+3/2; (iv) x−1/2, y, −z+3/2. |
The construction of hydrogen-bonded arrays by using molecular descriptors with unbalanced hydrogen-bond donor/acceptor ratios might redress the donor/acceptor imbalance by inclusion of molecules of water (Desiraju, 1990). Thus, bridged oxacycles in molecules possessing axially oriented hydroxy/carboxylic acid groups were considered promising candidates for studying the incorporation of water molecules into their hydrogen-bonded patterns (Carrasco et al., 2001). Our continuous interest in the study of the hydrated/anhydrous crystalline packing of such molecules has led us to consider the synthesis of the hydroxy acid 5,7,7-tris (hydroxymethyl)-6-oxabicyclo [3.2.1] octane-1-carboxylic acid (R = OH), (III), a dihydroxylated homologue of the diethyl derivative (R = Me), (IV), that shows a hydrated tubular-shaped structure in the solid state (Pérez et al., 2000). In the present paper, we report the crystal structure of the related lactones (I) and (II).
The molecular structures (Figs. 1 and 2) are quite rigid and contain three structural moieties that will be discussed separately. In both compounds and according to the notation of Giacovazzo et al. (1992), the γ-butyrolactone ring adopts conformations intermediate between 1T5 half chair and E5 envelope. The ring puckering parameters (Cremer & Pople, 1975) for the atom sequence C1/C2–C5 [q2 = 0.355 (2) and 0.312 (2) Å, and ϕ2 = −23.3 (3) and −29.8 (4)°] indicate that the conformation in (I) is essentially 1T5 with a contribution from E5, while in (II), the conformation is E5 with a contribution from 1T5. The cyclohexane ring adopts a 1C4 chair conformation, slightly distorted towards an 1H6 half chair in (I) and towards an E6 envelope in (II) for the sequences C1/C11/C10/C9/C8/C12 and C1/C11/C7–C10 [Q = 0.602 (2) and 0.655 (2) Å, θ = 15.4 (2) and 27.1 (2)°, and ϕ = −29.1 (5) and −59.1 (4)°]. The differences in the puckering amplitude could be ascribed to the different size of the oxacycle bridge; the larger size of the oxane in (I) versus the oxolane in (II) is associated with the lowest torsion angles in the bonds shared with this ring (Tables 1 and 3). The oxolane ring exhibits a 1C4 chair conformation distorted toward an 3H2 half chair for the atom sequence C1/C12/C8/C7/O6/C5 [Q = 0.561 (2) Å, θ = 20.1 (1)° and ϕ = 81.4 (5)°], whereas the oxane ring adopts a conformation intermediate between 1T2 and E2 for the C1/ C11/C7/O6/C5 sequence [q2 = 0.474 (2) Å and ϕ2 = 26.9 (2)°]. Another difference between the two structures is that the hydroxymethyl group attached to atom C5 is gauche- [in (I)] and trans-oriented [in (II)] with respect to atom C1 (Tables 1 and 3, and Figs. 1 and 2). As far as the conventional O—H···O bonds are concerned, two hydrogen-bonding networks are observed, viz. layers and staircase-ladders, which are closely related to the relative disposition of the dialcohols in each molecule, as previously observed in 1,3-diols (Nguyen et al., 2001; Schmittel et al., 2004). However, in both crystal structures, molecules connected by hydroxy-to-hydroxy bonds form chains, although they differ in the chirality of the components within each chain and the linkage between them, as described below. The molecules of (I) are linked into a sheet via a combination of hydroxy-to-hydroxy and hydroxy-to-carbonyl hydrogen bonds (Table 2). The formation of the sheets can be described in terms of chains with glide-related molecules running in the (102) direction (Fig. 3). Hydroxy-to-carbonyl contacts between chains, related by translation, are responsible for the extension in the a direction, so producing the two-dimensional network. C—H···O contacts exist (Table 2) within the sheet and between centrosymmetric sheets (dashed lines in Fig. 4), forming a three-dimensional framework.
In (II), each strand is formed by molecules related only by translation along a, where the hydroxy group of the hydroxymethyl group at atom C5 acts as a donor. The second hydroxy group connects screw-related strands (Fig. 5), giving rise to the staircase-ladder structure (Fig. 6a), as also happens in some recently reported 1,3-dialcohol derivatives (Nguyen et al., 2001). The another type of double-stranded ladder formed by dialcohols corresponds to the step-ladder structure schematically represented in Fig. 6(b), which has also been observed in the hydroxy acid analogues of (I) and (II) (Carrasco et al., 2001). In (II), as pointed out by Nguyen et al. (2001), each hydroxy group (gauche-oriented) acts as a donor and an acceptor of hydrogen bonds, showing (1) the preference of this type of ladder structure to be composed of only one enantiomer and (2) the twofold screw axis as the most probable symmetry for this type of ladder. The O···O intramolecular (A = O14···O16), interstrand (B = O16···O14ii) and intrastrand (C = O14···O16i) distances (Figs. 5 and 6a) of 5.396 (2), 2.700 (2) and 2.682 (2) Å characterizing this ladder are in the upper and lower end of the range reported by Nguyen et al. (2001). In (I), the intramolecular (O15···O16), interstrand (O16···O13ii) and intrastrand (O15···O16i) (Fig. 3) distances of 6.466 (3), 2.881 (2) and 2.715 (2) Å are all larger than the A, B and C distances in (II). The structures of both compounds highlight the competition between the OH···OH and OH···O═C hydrogen bonds. We also note that (II) is less dense than in (I) (the total packing coefficients are 0.685 and 0.712) and has a lower melting point (452–453 versus 464–465 K).
Only weak C—H···O interactions (Table 4) connect pairs of double strands, related by glide planes, along c into a three-dimensional network of corrugated centrosymmetric sheets (dashed lines in Fig. 7). The larger displacement parameters for atoms O3 and O12 in (II) can be associated with the lack of O—H···O contacts for these atoms.
Dihydroxy like hydroxy/carboxylic acid functions are hydrogen-bonded in linear anhydrous strands with two parallel strands cross-linked through additional hydrogen bonds. It would also be expected that incorporation of water molecules in dihydroxy hydogen-bonded networks might disrupt the dimeric motif creating single-strand arrays in a favourable conformation for ring packing. Further extension of the hydrogen bonding in the perpendicular direction can lead to the formation of a hydrated tubular-shaped structure in the solid state (Pérez et al., 2000). Work toward this end is in progress.