Methyl 2,3,4-tri-O-pivaloyl-β-D-xylo­pyran­oside

The crystal structure of the title compound, C₂₁H₃₆O₈, has been determined by X-ray analysis at 100 K. The six-membered pyran­osyl ring adopts a chair conform­ation.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.039
• wR factor = 0.094
• Data-to-parameter ratio = 8.3

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT222_ALERT_3_A Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       7.82 Ratio

Alert level C
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       3.50 Ratio
PLAT220_ALERT_2_C Large Non-Solvent    O     Ueq(max)/Ueq(min) ...       2.84 Ratio

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           29.00
           From the CIF: _reflns_number_total               3376
           Count of symmetry unique reflns         3396
           Completeness (_total/calc)             99.41%
           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

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

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

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Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2003); cell refinement: CrysAlis RED (Oxford Diffraction, 2003); data reduction: CrysAlis RED; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON98 (Spek, 2003); software used to prepare material for publication: SHELXL97.

Methyl 2,3,4-tri-O-pivaloyl-β-D-xylopyranoside

Crystal data

C21H36O8	F(000) = 452
Mr = 416.50	Dx = 1.173 Mg m^−3
Monoclinic, P21	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: P 2yb	Cell parameters from 1573 reflections
a = 9.828 (1) Å	θ = 15.0–25.0°
b = 6.849 (1) Å	µ = 0.09 mm^−1
c = 17.634 (1) Å	T = 100 K
β = 96.36 (1)°	Prismatic, colorless
V = 1179.7 (2) Å^3	0.3 × 0.3 × 0.2 mm
Z = 2

Data collection

Xcalibur CCD diffractometer	3234 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.088
Graphite monochromator	θmax = 29.0°, θmin = 4.6°
ω scans	h = −13→13
38147 measured reflections	k = −9→9
3376 independent reflections	l = −24→24

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)] = 0.039	Hydrogen site location: difference Fourier map
wR(F^2) = 0.094	H atoms treated by a mixture of independent and constrained refinement
S = 1.14	w = 1/[σ^2(Fo^2) + (0.0504P)^2 + 0.2141P] where P = (Fo^2 + 2Fc^2)/3
3376 reflections	(Δ/σ)max < 0.001
406 parameters	Δρmax = 0.37 e Å^−3
1 restraint	Δρmin = −0.21 e Å^−3

Special details

Experimental. The data did not permit the determination of the absolute structure; (the stereochemistry is the relative configuration based on the absolute stereochemistry of related compounds).

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.90467 (12)	0.9963 (2)	0.27885 (7)	0.0210 (3)
O2	0.67472 (12)	1.14493 (19)	0.33822 (6)	0.0177 (2)
O3	0.43427 (12)	1.17869 (19)	0.23208 (7)	0.0181 (2)
O4	0.40081 (11)	0.8702 (2)	0.12167 (6)	0.0206 (3)
O5	0.77279 (11)	0.8747 (2)	0.17460 (7)	0.0206 (3)
O6	0.73886 (19)	1.4510 (2)	0.31265 (8)	0.0374 (4)
O7	0.33988 (13)	1.0393 (2)	0.33006 (7)	0.0236 (3)
O8	0.41444 (17)	1.0010 (3)	0.00617 (9)	0.0502 (5)
C1	0.77493 (15)	0.9275 (3)	0.25305 (9)	0.0168 (3)
C2	0.67251 (16)	1.0922 (3)	0.25932 (9)	0.0143 (3)
C3	0.52954 (15)	1.0189 (3)	0.23020 (9)	0.0150 (3)
C4	0.53234 (16)	0.9531 (3)	0.14832 (9)	0.0171 (3)
C5	0.64225 (17)	0.7965 (3)	0.14567 (10)	0.0213 (3)
C6	1.00126 (17)	0.8407 (3)	0.29381 (12)	0.0262 (4)
C7	0.71448 (17)	1.3291 (3)	0.35805 (9)	0.0207 (3)
C8	0.72651 (18)	1.3565 (3)	0.44436 (10)	0.0258 (4)
C9	0.8546 (3)	1.2435 (6)	0.47813 (14)	0.0492 (7)
C10	0.7413 (4)	1.5740 (5)	0.46246 (15)	0.0500 (7)
C11	0.5994 (2)	1.2767 (4)	0.47661 (12)	0.0373 (5)
C12	0.34523 (16)	1.1722 (3)	0.28597 (9)	0.0163 (3)
C13	0.25306 (16)	1.3526 (3)	0.28059 (9)	0.0181 (3)
C14	0.3382 (2)	1.5371 (3)	0.27308 (12)	0.0254 (4)
C15	0.1789 (2)	1.3636 (3)	0.35238 (10)	0.0261 (4)
C16	0.14786 (17)	1.3264 (3)	0.20974 (10)	0.0226 (4)
C17	0.35381 (17)	0.9045 (3)	0.04765 (10)	0.0231 (4)
C18	0.21880 (18)	0.7985 (3)	0.02499 (10)	0.0234 (4)
C19	0.11581 (19)	0.8528 (4)	0.08105 (13)	0.0345 (5)
C20	0.1646 (2)	0.8584 (4)	−0.05658 (12)	0.0358 (5)
C21	0.2473 (2)	0.5787 (3)	0.02853 (12)	0.0297 (4)
H1	0.748 (2)	0.813 (3)	0.2817 (12)	0.012 (5)*
H2	0.696 (2)	1.203 (3)	0.2313 (12)	0.012 (5)*
H3	0.504 (2)	0.910 (3)	0.2612 (11)	0.011 (5)*
H4	0.554 (2)	1.060 (4)	0.1196 (12)	0.015 (5)*
H51	0.618 (2)	0.680 (4)	0.1751 (14)	0.024 (6)*
H52	0.650 (2)	0.759 (4)	0.0963 (13)	0.020 (5)*
H61	1.089 (3)	0.904 (4)	0.3153 (15)	0.033 (7)*
H62	0.970 (3)	0.749 (4)	0.3303 (16)	0.036 (7)*
H63	1.015 (3)	0.765 (4)	0.2466 (15)	0.031 (6)*
H91	0.846 (4)	1.107 (6)	0.466 (2)	0.057 (10)*
H92	0.863 (3)	1.261 (6)	0.533 (2)	0.066 (10)*
H93	0.940 (4)	1.297 (6)	0.459 (2)	0.066 (10)*
H101	0.818 (4)	1.629 (6)	0.446 (2)	0.066 (11)*
H102	0.652 (4)	1.646 (7)	0.439 (2)	0.086 (14)*
H103	0.748 (4)	1.585 (7)	0.522 (2)	0.073 (11)*
H111	0.590 (3)	1.130 (5)	0.4669 (17)	0.044 (8)*
H112	0.610 (3)	1.298 (5)	0.5322 (17)	0.041 (7)*
H113	0.515 (3)	1.348 (6)	0.4560 (17)	0.051 (8)*
H141	0.280 (2)	1.655 (4)	0.2735 (13)	0.022 (5)*
H142	0.413 (3)	1.550 (5)	0.3189 (16)	0.038 (7)*
H143	0.383 (3)	1.538 (5)	0.2262 (16)	0.039 (7)*
H151	0.113 (3)	1.479 (5)	0.3487 (17)	0.040 (7)*
H152	0.125 (3)	1.246 (5)	0.3617 (18)	0.042 (8)*
H153	0.244 (3)	1.385 (5)	0.3980 (16)	0.043 (8)*
H161	0.091 (2)	1.210 (4)	0.2149 (13)	0.017 (5)*
H162	0.191 (2)	1.310 (4)	0.1663 (14)	0.025 (6)*
H163	0.085 (3)	1.445 (4)	0.2023 (15)	0.033 (7)*
H191	0.153 (3)	0.821 (5)	0.1338 (17)	0.039 (7)*
H192	0.029 (3)	0.781 (5)	0.0696 (16)	0.035 (7)*
H193	0.096 (3)	0.989 (6)	0.0821 (19)	0.052 (9)*
H201	0.145 (3)	0.992 (5)	−0.0610 (16)	0.037 (7)*
H202	0.078 (3)	0.792 (5)	−0.0687 (16)	0.040 (7)*
H203	0.229 (3)	0.820 (5)	−0.0927 (18)	0.052 (9)*
H211	0.279 (3)	0.542 (5)	0.0833 (17)	0.044 (8)*
H212	0.161 (3)	0.509 (6)	0.0114 (18)	0.056 (9)*
H213	0.313 (3)	0.542 (5)	−0.0068 (18)	0.050 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0145 (5)	0.0204 (7)	0.0271 (6)	0.0005 (5)	−0.0021 (4)	−0.0005 (5)
O2	0.0213 (5)	0.0181 (6)	0.0132 (5)	−0.0020 (5)	0.0003 (4)	−0.0006 (4)
O3	0.0171 (5)	0.0195 (6)	0.0179 (5)	0.0031 (5)	0.0032 (4)	0.0034 (5)
O4	0.0189 (5)	0.0271 (7)	0.0149 (5)	−0.0070 (5)	−0.0024 (4)	0.0004 (5)
O5	0.0166 (5)	0.0253 (7)	0.0200 (5)	0.0006 (5)	0.0029 (4)	−0.0057 (5)
O6	0.0682 (11)	0.0214 (7)	0.0231 (7)	−0.0134 (8)	0.0064 (6)	−0.0018 (6)
O7	0.0253 (6)	0.0206 (7)	0.0261 (6)	0.0046 (5)	0.0083 (5)	0.0057 (5)
O8	0.0357 (7)	0.0768 (14)	0.0339 (8)	−0.0261 (9)	−0.0151 (6)	0.0298 (9)
C1	0.0142 (6)	0.0173 (8)	0.0184 (7)	−0.0008 (6)	0.0005 (5)	−0.0011 (6)
C2	0.0159 (6)	0.0152 (7)	0.0117 (6)	−0.0003 (6)	0.0008 (5)	−0.0011 (6)
C3	0.0140 (6)	0.0145 (7)	0.0163 (6)	0.0002 (6)	0.0009 (5)	0.0002 (6)
C4	0.0158 (6)	0.0193 (8)	0.0158 (7)	−0.0032 (6)	−0.0001 (5)	−0.0010 (6)
C5	0.0193 (7)	0.0218 (9)	0.0226 (7)	−0.0011 (7)	0.0020 (6)	−0.0071 (7)
C6	0.0176 (7)	0.0268 (10)	0.0338 (9)	0.0043 (7)	0.0005 (6)	0.0022 (8)
C7	0.0237 (7)	0.0190 (9)	0.0190 (7)	−0.0008 (7)	0.0001 (6)	−0.0027 (6)
C8	0.0274 (8)	0.0333 (10)	0.0167 (7)	−0.0059 (8)	0.0021 (6)	−0.0065 (7)
C9	0.0379 (12)	0.085 (2)	0.0226 (10)	0.0080 (13)	−0.0066 (8)	−0.0003 (12)
C10	0.0763 (19)	0.0427 (15)	0.0329 (11)	−0.0258 (15)	0.0143 (12)	−0.0192 (11)
C11	0.0379 (11)	0.0528 (16)	0.0231 (9)	−0.0126 (10)	0.0115 (8)	−0.0096 (10)
C12	0.0144 (6)	0.0190 (8)	0.0153 (6)	0.0000 (6)	0.0008 (5)	−0.0012 (6)
C13	0.0180 (6)	0.0171 (8)	0.0187 (7)	0.0038 (6)	0.0007 (5)	0.0009 (6)
C14	0.0255 (8)	0.0179 (9)	0.0321 (9)	0.0008 (7)	−0.0001 (7)	−0.0002 (8)
C15	0.0310 (8)	0.0259 (10)	0.0225 (8)	0.0102 (8)	0.0078 (7)	0.0021 (7)
C16	0.0200 (7)	0.0260 (10)	0.0209 (7)	0.0018 (7)	−0.0023 (6)	0.0030 (7)
C17	0.0200 (7)	0.0283 (10)	0.0197 (7)	−0.0012 (7)	−0.0037 (6)	0.0048 (7)
C18	0.0207 (7)	0.0293 (10)	0.0190 (7)	−0.0046 (7)	−0.0028 (6)	0.0000 (7)
C19	0.0188 (7)	0.0487 (15)	0.0356 (10)	−0.0022 (9)	0.0018 (7)	−0.0099 (10)
C20	0.0342 (10)	0.0431 (14)	0.0267 (9)	−0.0065 (10)	−0.0126 (8)	0.0056 (10)
C21	0.0331 (9)	0.0289 (11)	0.0263 (9)	−0.0051 (8)	−0.0006 (7)	−0.0018 (8)

Geometric parameters (Å, º)

O1—C1	1.3881 (19)	C10—H101	0.92 (4)
O1—C6	1.432 (2)	C10—H102	1.05 (5)
O2—C7	1.355 (2)	C10—H103	1.05 (4)
O2—C2	1.4352 (18)	C11—H111	1.02 (3)
O3—C12	1.3620 (19)	C11—H112	0.99 (3)
O3—C3	1.443 (2)	C11—H113	1.00 (3)
O4—C17	1.3560 (19)	C12—C13	1.529 (2)
O4—C4	1.4421 (19)	C13—C14	1.530 (3)
O5—C1	1.4278 (19)	C13—C15	1.531 (2)
O5—C5	1.431 (2)	C13—C16	1.541 (2)
O6—C7	1.199 (2)	C14—H141	0.99 (3)
O7—C12	1.202 (2)	C14—H142	1.03 (3)
O8—C17	1.193 (2)	C14—H143	0.98 (3)
C1—C2	1.524 (2)	C15—H151	1.02 (3)
C1—H1	0.99 (2)	C15—H152	0.99 (3)
C2—C3	1.527 (2)	C15—H153	0.98 (3)
C2—H2	0.95 (2)	C16—H161	0.98 (2)
C3—C4	1.515 (2)	C16—H162	0.92 (2)
C3—H3	0.98 (2)	C16—H163	1.02 (3)
C4—C5	1.527 (2)	C17—C18	1.526 (2)
C4—H4	0.93 (2)	C18—C21	1.532 (3)
C5—H51	1.00 (3)	C18—C20	1.533 (3)
C5—H52	0.92 (2)	C18—C19	1.537 (3)
C6—H61	1.00 (3)	C19—H191	0.99 (3)
C6—H62	0.97 (3)	C19—H192	0.98 (3)
C6—H63	1.00 (3)	C19—H193	0.96 (4)
C7—C8	1.525 (2)	C20—H201	0.93 (3)
C8—C10	1.527 (4)	C20—H202	0.97 (3)
C8—C11	1.530 (3)	C20—H203	0.98 (3)
C8—C9	1.540 (3)	C21—H211	1.01 (3)
C9—H91	0.96 (4)	C21—H212	0.99 (3)
C9—H92	0.97 (4)	C21—H213	0.98 (3)
C9—H93	1.01 (4)
C1—O1—C6	111.93 (14)	H102—C10—H103	108 (3)
C7—O2—C2	117.23 (13)	C8—C11—H111	110.7 (17)
C12—O3—C3	117.38 (13)	C8—C11—H112	108.6 (17)
C17—O4—C4	116.30 (13)	H111—C11—H112	108 (2)
C1—O5—C5	110.88 (12)	C8—C11—H113	112.0 (19)
O1—C1—O5	108.55 (12)	H111—C11—H113	111 (3)
O1—C1—C2	108.35 (14)	H112—C11—H113	106 (2)
O5—C1—C2	108.59 (12)	O7—C12—O3	123.62 (16)
O1—C1—H1	113.0 (12)	O7—C12—C13	125.74 (14)
O5—C1—H1	108.6 (12)	O3—C12—C13	110.63 (14)
C2—C1—H1	109.6 (12)	C12—C13—C14	110.32 (13)
O2—C2—C1	108.51 (12)	C12—C13—C15	108.77 (14)
O2—C2—C3	108.88 (12)	C14—C13—C15	110.23 (16)
C1—C2—C3	108.82 (13)	C12—C13—C16	107.22 (14)
O2—C2—H2	108.9 (13)	C14—C13—C16	110.49 (15)
C1—C2—H2	110.9 (12)	C15—C13—C16	109.75 (14)
C3—C2—H2	110.9 (12)	C13—C14—H141	110.7 (14)
O3—C3—C4	109.13 (13)	C13—C14—H142	110.7 (17)
O3—C3—C2	108.55 (14)	H141—C14—H142	106 (2)
C4—C3—C2	107.77 (12)	C13—C14—H143	112.3 (18)
O3—C3—H3	111.0 (12)	H141—C14—H143	108 (2)
C4—C3—H3	109.9 (12)	H142—C14—H143	108 (2)
C2—C3—H3	110.5 (12)	C13—C15—H151	110.1 (17)
O4—C4—C3	108.50 (12)	C13—C15—H152	114.1 (18)
O4—C4—C5	108.97 (15)	H151—C15—H152	107 (2)
C3—C4—C5	109.00 (13)	C13—C15—H153	111.1 (16)
O4—C4—H4	112.6 (13)	H151—C15—H153	107 (3)
C3—C4—H4	108.4 (14)	H152—C15—H153	107 (3)
C5—C4—H4	109.2 (13)	C13—C16—H161	110.8 (13)
O5—C5—C4	109.61 (14)	C13—C16—H162	111.0 (15)
O5—C5—H51	112.0 (14)	H161—C16—H162	107 (2)
C4—C5—H51	109.4 (14)	C13—C16—H163	110.8 (16)
O5—C5—H52	105.9 (14)	H161—C16—H163	108.4 (19)
C4—C5—H52	111.2 (15)	H162—C16—H163	108 (2)
H51—C5—H52	109 (2)	O8—C17—O4	123.09 (16)
O1—C6—H61	105.9 (17)	O8—C17—C18	125.57 (16)
O1—C6—H62	110.7 (16)	O4—C17—C18	111.31 (14)
H61—C6—H62	110 (2)	C17—C18—C21	107.88 (16)
O1—C6—H63	112.3 (16)	C17—C18—C20	108.69 (16)
H61—C6—H63	111 (2)	C21—C18—C20	110.12 (18)
H62—C6—H63	107 (2)	C17—C18—C19	109.41 (15)
O6—C7—O2	123.31 (16)	C21—C18—C19	109.99 (19)
O6—C7—C8	125.55 (18)	C20—C18—C19	110.71 (18)
O2—C7—C8	111.13 (15)	C18—C19—H191	110.5 (16)
C7—C8—C10	108.88 (18)	C18—C19—H192	111.4 (16)
C7—C8—C11	110.53 (15)	H191—C19—H192	108 (2)
C10—C8—C11	109.5 (2)	C18—C19—H193	114 (2)
C7—C8—C9	107.08 (17)	H191—C19—H193	105 (3)
C10—C8—C9	110.8 (2)	H192—C19—H193	109 (3)
C11—C8—C9	110.1 (2)	C18—C20—H201	112.7 (18)
C8—C9—H91	110 (2)	C18—C20—H202	106.7 (17)
C8—C9—H92	108 (2)	H201—C20—H202	106 (3)
H91—C9—H92	110 (3)	C18—C20—H203	110.7 (18)
C8—C9—H93	111 (2)	H201—C20—H203	110 (3)
H91—C9—H93	110 (3)	H202—C20—H203	110 (2)
H92—C9—H93	108 (3)	C18—C21—H211	108.7 (18)
C8—C10—H101	113 (3)	C18—C21—H212	108 (2)
C8—C10—H102	109 (3)	H211—C21—H212	110 (3)
H101—C10—H102	111 (4)	C18—C21—H213	111 (2)
C8—C10—H103	106 (2)	H211—C21—H213	113 (3)
H101—C10—H103	109 (3)	H212—C21—H213	107 (3)