2,3-C-Dimethyl-3,4-O-isopropyl­idene-D-allono-1,5-lactone

The relative configuration of the title compound, C₁₁H₁₈O₆, was firmly established by X-ray crystallographic analysis. The absolute configuration was determined by the use of 2-C-methyl-D-ribono-1,4-lactone as the starting material. The structure exists as a hydrogen-bonded network, with each mol­ecule acting as a donor and acceptor for two hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 150 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.032
• wR factor = 0.073
• Data-to-parameter ratio = 10.1

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT415_ALERT_2_B Short Inter D-H..H-X       H5     ..  H61     ..       2.09 Ang.

Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.830     0.990
            Tmin(prime) and Tmax expected:      0.977     0.994
            RR(prime) =      0.853
            Please check that your absorption correction is appropriate.
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large .............       0.85

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           27.48
           From the CIF: _reflns_number_total               1561
           Count of symmetry unique reflns         1597
           Completeness (_total/calc)             97.75%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C1     = .          R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C2     = .          R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C5     = .          R
PLAT791_ALERT_1_G Confirm the Absolute Configuration of C6     = .          R

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   2 ALERT level C = Check and explain
   5 ALERT level G = General alerts; check

   4 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Branched sugars are a relatively unstudied class of compounds but recent biological results have indicated they could have a potential use as therapeutics (Mitchell et al. 2007). The Kiliani ascension on ketoses and deoxy ketoses has proved a valuable route towards branched sugars (Hotchkiss et al., 2004,2006; Soengas et al., 2005; Jones, Watkin et al. 2007). Currently, there are very limited examples of di-branched carbohydrates reported. Examples of sugars that contain two carbon branches in the literature include 2,4-C-dimethyl-3,4-O-isopropylidene-L-arabinono-1,5-lactone (Booth, Watkin et al. 2007) and various protected forms of 3,5-C-dimethyl-mannono and glucono lactone (Booth, Jenkinson, Fleet & Watkin, 2007a, 2007b, 2007c). 2-C-Hydroxymethyl-2,3-O-isopropylidene-3-C-methyl-β-L– erythrose (Booth, Jenkinson, Watkin & Fleet, 2007d) is a rare example of a sugar with adjacent branched centres.

The crystal structure of the title compound (Fig. 1) exists as a three dimensionally hydrogen bonded network (Fig. 2) with each molecule acting as an acceptor and a donor for two hydrogen bonds.

Related literature

For related literature see: Jones, Curran et al. (2007); Jones, Watkin et al. (2007); Mitchell et al. (2007); Hotchkiss et al. (2004, 2006); Soengas et al. (2005); Booth, Watkin et al. (2007); Booth et al. (2007a, 2007b, 2007c, 2007d); Curran et al. (2007); Görbitz (1999).

S2. Experimental

Treatment of 1-deoxy-3-C-methyl-D-psicose 2 (Jones et al. in preparation) derived from 2-C-methyl-D-ribono-1,4-lactone 1 (Hotchkiss et al., 2006), with sodium cyanide, gave a mixture of the 2,6-anhydro derivative 3 (Curran et al. 2007) and the lactone 4 (Fig. 3). X-Ray crystallographic analysis of the title lactone 3 removed any ambiguity as to the stereochemistry at the new C-2 chiral centre. The title compound was recrystallized from a mixture of cyclohexane and ethyl acetate; m.p. 420 K; [α]_D²² +106.1 (c, 0.64 in chlororform).

S3. Refinement

In the absence of significant anomalous scattering, Friedel pairs were merged and the absolute configuration was assigned from the starting material.

The relatively large ratio of minimum to maximum corrections applied in the multiscan process (1:1.19) reflect changes in the illuminated volume of the crystal. Changes in illuminated volume were kept to a minimum, and were taken into account (Görbitz, 1999) by the multi-scan inter-frame scaling (DENZO/SCALEPACK, Otwinowski & Minor, 1997).

The H atoms were all located in a difference map, but those attached to carbon atoms were repositioned geometrically. The H atoms were initially refined with soft restraints on the bond lengths and angles to regularize their geometry (C—H in the range 0.93–0.98, O—H = 0.82 Å) and U_iso(H) (in the range 1.2–1.5 times U_eq of the parent atom), after which the positions were refined with riding constraints.

Computing details

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.

Figures

	Fig. 1. The title compound with displacement ellipsoids drawn at the 50% probability level. H atoms are shown as spheres of arbitary radius.
	Fig. 2. The packing of the title compound projected along the a-axis. Hydrogen bonds are shown as dotted lines.
	Fig. 3. The reaction scheme.

2,3-C-Dimethyl-3,4-O-isopropylidene-D-allono-1,5-lactone

Crystal data

C11H18O6	F(000) = 528
Mr = 246.26	Dx = 1.361 Mg m^−3
Orthorhombic, P212121	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ac 2ab	Cell parameters from 1357 reflections
a = 6.9089 (2) Å	θ = 5–27°
b = 12.2072 (5) Å	µ = 0.11 mm^−1
c = 14.2507 (5) Å	T = 150 K
V = 1201.88 (7) Å^3	Plate, colourless
Z = 4	0.20 × 0.20 × 0.05 mm

Data collection

Nonius KappaCCD diffractometer	1303 reflections with I > 2.0σ(I)
Graphite monochromator	Rint = 0.031
ω scans	θmax = 27.5°, θmin = 5.2°
Absorption correction: multi-scan (DENZO/SCALEPACK; Otwinowski & Minor, 1997)	h = −8→8
Tmin = 0.83, Tmax = 0.99	k = −15→15
5554 measured reflections	l = −18→18
1561 independent reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.032	H-atom parameters constrained
wR(F^2) = 0.073	w = 1/[σ^2(F^2) + (0.03P)^2 + 0.22P], where P = [max(Fo^2,0) + 2Fc^2]/3
S = 0.92	(Δ/σ)max = 0.000203
1561 reflections	Δρmax = 0.26 e Å^−3
154 parameters	Δρmin = −0.24 e Å^−3
0 restraints

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

	x	y	z	Uiso*/Ueq
C1	0.6355 (3)	0.35060 (15)	0.21409 (12)	0.0168
C2	0.7020 (3)	0.45680 (13)	0.26378 (12)	0.0185
C3	0.7261 (3)	0.42656 (14)	0.36718 (13)	0.0225
O4	0.5794 (2)	0.37424 (10)	0.40921 (8)	0.0233
C5	0.4030 (3)	0.34688 (15)	0.35788 (12)	0.0191
C6	0.4458 (3)	0.30862 (13)	0.25760 (12)	0.0173
O7	0.29790 (19)	0.34924 (10)	0.19778 (8)	0.0190
C8	0.3790 (3)	0.35046 (16)	0.10563 (12)	0.0194
O9	0.57947 (19)	0.38010 (10)	0.12033 (8)	0.0198
C10	0.2817 (3)	0.43932 (15)	0.04956 (13)	0.0249
C11	0.3659 (3)	0.23797 (15)	0.06080 (13)	0.0262
C12	0.3044 (3)	0.25957 (14)	0.41507 (13)	0.0234
O13	0.4187 (2)	0.16239 (10)	0.41357 (8)	0.0249
O14	0.8717 (2)	0.44346 (11)	0.41227 (9)	0.0336
O15	0.54750 (19)	0.53432 (9)	0.26178 (9)	0.0216
C16	0.8859 (3)	0.50609 (16)	0.22511 (14)	0.0263
C17	0.7921 (3)	0.26278 (15)	0.21373 (13)	0.0238
H51	0.3215	0.4124	0.3552	0.0251*
H61	0.4470	0.2263	0.2567	0.0225*
H101	0.3438	0.4423	−0.0118	0.0346*
H102	0.2985	0.5093	0.0839	0.0349*
H103	0.1455	0.4193	0.0424	0.0349*
H111	0.4183	0.2437	−0.0033	0.0397*
H112	0.4415	0.1852	0.0988	0.0394*
H113	0.2318	0.2141	0.0579	0.0391*
H121	0.2880	0.2871	0.4802	0.0300*
H122	0.1741	0.2432	0.3886	0.0301*
H161	0.9086	0.5757	0.2581	0.0405*
H162	0.9937	0.4554	0.2353	0.0400*
H163	0.8697	0.5198	0.1581	0.0397*
H171	0.7428	0.1979	0.1804	0.0363*
H172	0.9047	0.2937	0.1824	0.0372*
H173	0.8235	0.2434	0.2792	0.0366*
H5	0.5431	0.5604	0.2065	0.0319*
H19	0.3990	0.1194	0.4586	0.0389*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0184 (9)	0.0180 (9)	0.0140 (8)	0.0009 (8)	−0.0006 (8)	0.0008 (7)
C2	0.0215 (10)	0.0159 (7)	0.0181 (8)	0.0009 (8)	−0.0027 (8)	0.0033 (8)
C3	0.0301 (12)	0.0158 (8)	0.0216 (9)	−0.0012 (9)	−0.0041 (9)	−0.0001 (8)
O4	0.0286 (8)	0.0239 (7)	0.0173 (6)	−0.0042 (7)	−0.0033 (6)	0.0011 (6)
C5	0.0204 (10)	0.0199 (9)	0.0169 (8)	0.0024 (9)	0.0000 (8)	0.0005 (8)
C6	0.0181 (9)	0.0165 (8)	0.0172 (8)	0.0006 (8)	0.0003 (9)	0.0003 (8)
O7	0.0157 (7)	0.0246 (7)	0.0166 (6)	0.0007 (6)	−0.0010 (6)	0.0013 (6)
C8	0.0157 (10)	0.0267 (10)	0.0158 (8)	−0.0028 (9)	0.0016 (8)	0.0012 (8)
O9	0.0172 (7)	0.0270 (7)	0.0153 (6)	−0.0030 (6)	−0.0005 (6)	0.0012 (5)
C10	0.0229 (11)	0.0283 (10)	0.0234 (9)	−0.0010 (10)	−0.0045 (9)	0.0060 (9)
C11	0.0289 (11)	0.0287 (10)	0.0210 (9)	−0.0025 (10)	−0.0037 (9)	−0.0021 (9)
C12	0.0267 (11)	0.0234 (9)	0.0202 (9)	0.0010 (10)	0.0057 (9)	0.0011 (8)
O13	0.0355 (8)	0.0184 (6)	0.0208 (6)	0.0030 (7)	0.0048 (6)	0.0049 (5)
O14	0.0384 (9)	0.0354 (8)	0.0272 (7)	−0.0107 (8)	−0.0143 (7)	0.0073 (7)
O15	0.0279 (8)	0.0153 (5)	0.0217 (6)	0.0026 (6)	−0.0007 (7)	0.0029 (6)
C16	0.0242 (11)	0.0258 (10)	0.0288 (10)	−0.0055 (9)	−0.0040 (10)	0.0066 (9)
C17	0.0223 (10)	0.0223 (9)	0.0268 (10)	0.0049 (9)	−0.0008 (9)	−0.0014 (8)

Geometric parameters (Å, º)

C1—C2	1.547 (2)	C8—C11	1.517 (3)
C1—C6	1.538 (2)	C10—H101	0.975
C1—O9	1.437 (2)	C10—H102	0.991
C1—C17	1.524 (2)	C10—H103	0.977
C2—C3	1.528 (2)	C11—H111	0.985
C2—O15	1.427 (2)	C11—H112	0.990
C2—C16	1.510 (3)	C11—H113	0.972
C3—O4	1.339 (2)	C12—O13	1.425 (2)
C3—O14	1.212 (2)	C12—H121	0.994
O4—C5	1.460 (2)	C12—H122	0.996
C5—C6	1.532 (2)	O13—H19	0.840
C5—C12	1.505 (3)	O15—H5	0.850
C5—H51	0.979	C16—H161	0.983
C6—O7	1.420 (2)	C16—H162	0.979
C6—H61	1.005	C16—H163	0.976
O7—C8	1.428 (2)	C17—H171	0.984
C8—O9	1.447 (2)	C17—H172	0.972
C8—C10	1.506 (3)	C17—H173	0.987
C2—C1—C6	110.36 (15)	C10—C8—C11	113.71 (15)
C2—C1—O9	107.19 (13)	C8—O9—C1	109.25 (14)
C6—C1—O9	103.24 (13)	C8—C10—H101	107.8
C2—C1—C17	112.35 (15)	C8—C10—H102	107.8
C6—C1—C17	111.86 (14)	H101—C10—H102	111.0
O9—C1—C17	111.37 (14)	C8—C10—H103	107.8
C1—C2—C3	105.74 (13)	H101—C10—H103	109.8
C1—C2—O15	108.93 (14)	H102—C10—H103	112.3
C3—C2—O15	105.12 (15)	C8—C11—H111	107.8
C1—C2—C16	114.64 (16)	C8—C11—H112	109.1
C3—C2—C16	110.89 (16)	H111—C11—H112	111.1
O15—C2—C16	110.97 (13)	C8—C11—H113	110.2
C2—C3—O4	117.66 (17)	H111—C11—H113	109.3
C2—C3—O14	124.09 (18)	H112—C11—H113	109.3
O4—C3—O14	118.19 (16)	C5—C12—O13	109.30 (15)
C3—O4—C5	121.10 (13)	C5—C12—H121	108.6
O4—C5—C6	112.08 (15)	O13—C12—H121	111.0
O4—C5—C12	105.58 (14)	C5—C12—H122	110.2
C6—C5—C12	112.12 (15)	O13—C12—H122	109.2
O4—C5—H51	108.2	H121—C12—H122	108.6
C6—C5—H51	108.9	C12—O13—H19	114.7
C12—C5—H51	109.9	C2—O15—H5	107.0
C1—C6—C5	116.03 (15)	C2—C16—H161	107.7
C1—C6—O7	104.76 (12)	C2—C16—H162	109.5
C5—C6—O7	108.34 (14)	H161—C16—H162	110.7
C1—C6—H61	108.7	C2—C16—H163	109.2
C5—C6—H61	108.5	H161—C16—H163	109.8
O7—C6—H61	110.4	H162—C16—H163	109.9
C6—O7—C8	105.87 (13)	C1—C17—H171	108.8
O7—C8—O9	104.19 (13)	C1—C17—H172	107.3
O7—C8—C10	108.69 (15)	H171—C17—H172	111.6
O9—C8—C10	108.91 (15)	C1—C17—H173	108.7
O7—C8—C11	110.77 (15)	H171—C17—H173	109.9
O9—C8—C11	110.13 (16)	H172—C17—H173	110.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O15—H5···O13^i	0.85	2.13	2.957 (2)	163
O13—H19···O14^ii	0.84	2.00	2.817 (2)	163

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