1,6-Anhydro-2,3-di-O-benzyl-5C-[(R)-ethoxycarbonyl(hydroxy)methyl]-β-L-altrofuranose

The crystal structure of the title compound, C₂₄H₂₈O₈, has been determined. The conformation of the furan­ose ring can be described as 58% ideal envelope ^OE conformer and 42% ideal twisted ^OT₁ conformer. The 1,3-dioxane ring adopts a chair conformation with the anhydro-O atom pointing upwards. Both phenyl rings are quasi-perpendicular to the mean plane of the furan­ose ring. The hydrogen bonding is intermolecular and consists of infinite chains parallel to the a axis.

Computing details

Data collection: CAD-4 Software (Enraf-Nonius, 1989); cell refinement: CAD-4 Software; data reduction: maXus (Mackay et al., 1999); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: maXus.

1,6-Anhydro-2,3-di-O-benzyl-5 C-[(R)-ethoxycarbonyl(hydroxy)methyl]-L– altrofuranose

Crystal data

C24H28O8	Dx = 1.326 Mg m^−3
Mr = 444.46	Cu Kα radiation, λ = 1.54180 Å
Orthorhombic, P212121	Cell parameters from 25 reflections
a = 5.6740 (14) Å	θ = 9.5–32.9°
b = 11.699 (6) Å	µ = 0.83 mm^−1
c = 33.5340 (15) Å	T = 293 K
V = 2226.0 (13) Å^3	Prismatic, colourless
Z = 4	0.40 × 0.25 × 0.25 mm
F(000) = 944

Data collection

Enraf-Nonius MACH3 diffractometer	Rint = 0.000
Radiation source: Nonius FR591 rotating Cu anode	θmax = 70.0°, θmin = 2.6°
Graphite monochromator	h = 0→6
ω/2θ scans	k = 0→14
2447 measured reflections	l = 0→40
2447 independent reflections	3 standard reflections every 60 min
1942 reflections with I > 2σ(I)	intensity decay: 0.2%

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)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.148	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0816P)^2 + 0.5716P] where P = (Fo^2 + 2Fc^2)/3
2447 reflections	(Δ/σ)max < 0.001
289 parameters	Δρmax = 0.22 e Å^−3
0 restraints	Δρmin = −0.21 e Å^−3

Special details

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	0.7901 (6)	0.6073 (3)	0.14208 (8)	0.0920 (9)
C1	0.8302 (7)	0.7212 (5)	0.15612 (12)	0.0890 (14)
H11	0.9408	0.7199	0.1785	0.116*
C2	0.6094 (6)	0.7855 (3)	0.16776 (10)	0.0680 (9)
H21	0.6528	0.8490	0.1854	0.088*
C3	0.5215 (6)	0.8341 (3)	0.12800 (10)	0.0622 (8)
H31	0.3762	0.7952	0.1198	0.081*
C4	0.7208 (6)	0.8046 (4)	0.09952 (11)	0.0729 (10)
H41	0.7475	0.8666	0.0804	0.095*
O4	0.9225 (5)	0.7889 (3)	0.12487 (9)	0.1065 (12)
C5	0.6807 (6)	0.6893 (4)	0.07783 (10)	0.0683 (10)
C6	0.6254 (8)	0.6006 (3)	0.10985 (10)	0.0758 (10)
H61	0.4672	0.6132	0.1199	0.099*
H62	0.6310	0.5248	0.0982	0.099*
O5	0.8922 (5)	0.6571 (4)	0.05771 (8)	0.1104 (13)
H5	0.8851	0.6775	0.0343	0.144*
C7	0.4882 (6)	0.7014 (3)	0.04625 (11)	0.0644 (8)
H71	0.3352	0.7142	0.0590	0.084*
O7	0.5486 (5)	0.7962 (2)	0.02231 (8)	0.0848 (9)
H7	0.4282	0.8295	0.0153	0.110*
C8	0.4785 (6)	0.5947 (3)	0.02018 (11)	0.0686 (9)
O8	0.5528 (6)	0.5882 (3)	−0.01323 (9)	0.0946 (9)
O9	0.3750 (5)	0.5093 (2)	0.03964 (8)	0.0810 (8)
C9	0.3541 (12)	0.4011 (4)	0.01875 (15)	0.1029 (16)
H91	0.4843	0.3922	0.0003	0.134*
H92	0.3596	0.3385	0.0377	0.134*
C10	0.1332 (16)	0.3987 (5)	−0.0027 (2)	0.137 (2)
H10	0.1182	0.3271	−0.0165	0.178*
H10B	0.1297	0.4601	−0.0217	0.178*
H10C	0.0051	0.4072	0.0157	0.178*
O3	0.4794 (6)	0.9548 (2)	0.13268 (8)	0.0820 (8)
C11	0.3235 (8)	0.9966 (3)	0.10342 (11)	0.0782 (11)
H11B	0.1773	0.9538	0.1043	0.102*
H11C	0.3927	0.9870	0.0772	0.102*
C12	0.2748 (7)	1.1203 (3)	0.11076 (10)	0.0654 (9)
C13	0.4263 (9)	1.1911 (3)	0.13033 (12)	0.0808 (11)
H13	0.5691	1.1622	0.1395	0.105*
C14	0.3731 (11)	1.3047 (4)	0.13690 (15)	0.0984 (15)
H14	0.4814	1.3510	0.1500	0.128*
C15	0.1682 (11)	1.3490 (4)	0.12474 (15)	0.0977 (15)
H15	0.1309	1.4249	0.1302	0.127*
C16	0.0142 (10)	1.2812 (4)	0.10417 (16)	0.1049 (15)
H16	−0.1263	1.3118	0.0947	0.136*
C17	0.0661 (9)	1.1671 (4)	0.09742 (15)	0.0925 (13)
H17	−0.0410	1.1216	0.0837	0.120*
O2	0.4317 (4)	0.7205 (2)	0.18621 (6)	0.0656 (6)
C18	0.4966 (9)	0.6844 (4)	0.22553 (11)	0.0931 (13)
H18	0.5188	0.7504	0.2426	0.121*
H18B	0.6433	0.6419	0.2246	0.121*
C19	0.3039 (7)	0.6103 (3)	0.24169 (9)	0.0672 (9)
C20	0.2348 (13)	0.5154 (4)	0.22282 (15)	0.1144 (18)
H20	0.3085	0.4956	0.1990	0.149*
C21	0.0636 (19)	0.4479 (6)	0.2369 (2)	0.159 (3)
H21B	0.0202	0.3831	0.2226	0.207*
C22	−0.0458 (13)	0.4717 (7)	0.2710 (2)	0.136 (3)
H22	−0.1614	0.4228	0.2808	0.177*
C23	0.0108 (14)	0.5649 (8)	0.29078 (16)	0.140 (3)
H23	−0.0673	0.5829	0.3143	0.181*
C24	0.1905 (12)	0.6378 (5)	0.27625 (12)	0.1084 (17)
H24	0.2309	0.7037	0.2901	0.141*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0818 (19)	0.118 (2)	0.0761 (15)	0.0400 (19)	0.0012 (15)	0.0385 (16)
C1	0.055 (2)	0.137 (4)	0.075 (2)	−0.011 (3)	−0.0155 (18)	0.045 (3)
C2	0.0616 (19)	0.077 (2)	0.0649 (17)	−0.0138 (19)	−0.0178 (16)	0.0123 (17)
C3	0.0604 (19)	0.0586 (17)	0.0676 (18)	−0.0135 (17)	−0.0193 (16)	0.0143 (15)
C4	0.0461 (17)	0.099 (3)	0.0737 (19)	−0.0198 (19)	−0.0174 (16)	0.035 (2)
O4	0.0492 (13)	0.182 (3)	0.0878 (17)	−0.0314 (19)	−0.0206 (13)	0.063 (2)
C5	0.0404 (15)	0.099 (3)	0.0660 (18)	0.0145 (18)	0.0056 (14)	0.0297 (19)
C6	0.083 (3)	0.075 (2)	0.0689 (19)	0.025 (2)	0.008 (2)	0.0194 (17)
O5	0.0619 (15)	0.200 (4)	0.0690 (15)	0.047 (2)	0.0153 (13)	0.042 (2)
C7	0.0513 (17)	0.0682 (18)	0.074 (2)	0.0036 (17)	−0.0021 (16)	0.0171 (16)
O7	0.0921 (19)	0.0736 (14)	0.0887 (16)	−0.0150 (15)	−0.0386 (16)	0.0318 (13)
C8	0.0559 (19)	0.0687 (19)	0.081 (2)	0.0126 (17)	0.0129 (18)	0.0184 (17)
O8	0.106 (2)	0.0917 (18)	0.0866 (17)	0.0068 (19)	0.0311 (18)	0.0105 (15)
O9	0.0897 (19)	0.0704 (14)	0.0827 (15)	−0.0150 (15)	0.0141 (15)	0.0085 (13)
C9	0.138 (5)	0.064 (2)	0.106 (3)	0.000 (3)	0.014 (4)	0.004 (2)
C10	0.171 (6)	0.092 (3)	0.147 (5)	−0.020 (4)	−0.030 (5)	−0.015 (3)
O3	0.102 (2)	0.0600 (12)	0.0844 (15)	−0.0180 (15)	−0.0386 (16)	0.0104 (11)
C11	0.098 (3)	0.0642 (19)	0.073 (2)	−0.010 (2)	−0.027 (2)	0.0056 (16)
C12	0.075 (2)	0.0596 (18)	0.0618 (17)	−0.0117 (19)	0.0039 (18)	0.0049 (15)
C13	0.086 (3)	0.069 (2)	0.088 (2)	−0.001 (2)	−0.005 (2)	−0.0082 (19)
C14	0.117 (4)	0.070 (2)	0.108 (3)	−0.001 (3)	−0.007 (3)	−0.025 (2)
C15	0.113 (4)	0.072 (2)	0.108 (3)	0.008 (3)	0.019 (3)	−0.005 (2)
C16	0.100 (4)	0.082 (3)	0.133 (4)	0.009 (3)	−0.004 (3)	0.023 (3)
C17	0.091 (3)	0.078 (2)	0.109 (3)	−0.014 (3)	−0.017 (3)	0.015 (2)
O2	0.0633 (13)	0.0786 (14)	0.0550 (11)	−0.0068 (13)	−0.0066 (10)	0.0148 (10)
C18	0.101 (3)	0.115 (3)	0.0631 (19)	−0.026 (3)	−0.019 (2)	0.026 (2)
C19	0.076 (2)	0.076 (2)	0.0487 (15)	0.010 (2)	−0.0028 (16)	0.0111 (15)
C20	0.153 (5)	0.094 (3)	0.095 (3)	−0.027 (4)	0.026 (4)	−0.021 (3)
C21	0.208 (9)	0.128 (5)	0.143 (5)	−0.068 (6)	−0.001 (6)	0.023 (4)
C22	0.101 (4)	0.178 (7)	0.130 (5)	−0.024 (5)	−0.013 (4)	0.097 (5)
C23	0.135 (6)	0.208 (7)	0.076 (3)	0.046 (6)	0.044 (4)	0.037 (4)
C24	0.156 (5)	0.108 (3)	0.061 (2)	0.018 (4)	0.013 (3)	0.000 (2)

Geometric parameters (Å, º)

O1—C1	1.431 (6)	C9—C10	1.446 (10)
O1—C6	1.431 (5)	O3—C11	1.409 (4)
C1—O4	1.414 (5)	C11—C12	1.493 (5)
C1—C2	1.512 (6)	C12—C13	1.363 (5)
C2—O2	1.406 (4)	C12—C17	1.379 (6)
C2—C3	1.533 (4)	C13—C14	1.380 (6)
C3—O3	1.441 (4)	C14—C15	1.337 (8)
C3—C4	1.520 (6)	C15—C16	1.367 (7)
C4—O4	1.438 (4)	C16—C17	1.385 (7)
C4—C5	1.549 (6)	O2—C18	1.433 (4)
C5—O5	1.427 (4)	C18—C19	1.497 (6)
C5—C6	1.526 (5)	C19—C20	1.337 (6)
C5—C7	1.528 (5)	C19—C24	1.364 (6)
C7—O7	1.411 (4)	C20—C21	1.338 (10)
C7—C8	1.525 (5)	C21—C22	1.332 (10)
C8—O8	1.199 (4)	C22—C23	1.315 (9)
C8—O9	1.330 (4)	C23—C24	1.416 (10)
O9—C9	1.452 (5)
C1—O1—C6	113.8 (3)	O8—C8—C7	125.1 (3)
O4—C1—O1	109.7 (4)	O9—C8—C7	110.5 (3)
O4—C1—C2	102.7 (4)	C8—O9—C9	117.0 (3)
O1—C1—C2	114.6 (3)	C10—C9—O9	109.2 (5)
O2—C2—C1	116.0 (3)	C11—O3—C3	111.7 (3)
O2—C2—C3	110.5 (3)	O3—C11—C12	109.8 (3)
C1—C2—C3	103.3 (3)	C13—C12—C17	117.1 (4)
O3—C3—C4	114.4 (3)	C13—C12—C11	123.5 (4)
O3—C3—C2	108.8 (3)	C17—C12—C11	119.4 (4)
C4—C3—C2	102.7 (3)	C12—C13—C14	121.6 (5)
O4—C4—C3	104.5 (3)	C15—C14—C13	121.0 (5)
O4—C4—C5	106.4 (3)	C14—C15—C16	119.0 (5)
C3—C4—C5	112.5 (3)	C15—C16—C17	120.4 (5)
C1—O4—C4	102.4 (3)	C12—C17—C16	120.8 (5)
O5—C5—C6	109.0 (3)	C2—O2—C18	112.4 (3)
O5—C5—C7	107.3 (3)	O2—C18—C19	108.4 (3)
C6—C5—C7	113.8 (3)	C20—C19—C24	117.4 (5)
O5—C5—C4	109.2 (3)	C20—C19—C18	121.6 (4)
C6—C5—C4	107.0 (3)	C24—C19—C18	121.0 (4)
C7—C5—C4	110.5 (3)	C19—C20—C21	122.4 (6)
O1—C6—C5	111.1 (3)	C22—C21—C20	121.2 (7)
O7—C7—C8	109.0 (3)	C23—C22—C21	119.5 (6)
O7—C7—C5	107.1 (3)	C22—C23—C24	120.1 (5)
C8—C7—C5	110.3 (3)	C19—C24—C23	119.3 (5)
O8—C8—O9	124.5 (4)
C6—O1—C1—O4	−60.6 (4)	O7—C7—C8—O8	12.9 (5)
C6—O1—C1—C2	54.2 (4)	C5—C7—C8—O8	−104.4 (4)
O4—C1—C2—O2	155.5 (3)	O7—C7—C8—O9	−166.9 (3)
O1—C1—C2—O2	36.7 (4)	C5—C7—C8—O9	75.8 (4)
O4—C1—C2—C3	34.6 (4)	O8—C8—O9—C9	0.6 (6)
O1—C1—C2—C3	−84.3 (3)	C7—C8—O9—C9	−179.5 (4)
O2—C2—C3—O3	106.4 (3)	C8—O9—C9—C10	−90.2 (6)
C1—C2—C3—O3	−128.9 (3)	C4—C3—O3—C11	87.0 (4)
O2—C2—C3—C4	−131.9 (3)	C2—C3—O3—C11	−158.8 (3)
C1—C2—C3—C4	−7.3 (4)	C3—O3—C11—C12	176.9 (3)
O3—C3—C4—O4	95.8 (3)	O3—C11—C12—C13	25.8 (5)
C2—C3—C4—O4	−21.9 (4)	O3—C11—C12—C17	−154.0 (4)
O3—C3—C4—C5	−149.1 (3)	C17—C12—C13—C14	0.6 (6)
C2—C3—C4—C5	93.1 (3)	C11—C12—C13—C14	−179.2 (4)
O1—C1—O4—C4	72.7 (4)	C12—C13—C14—C15	1.0 (8)
C2—C1—O4—C4	−49.6 (4)	C13—C14—C15—C16	−2.5 (8)
C3—C4—O4—C1	45.0 (4)	C14—C15—C16—C17	2.5 (8)
C5—C4—O4—C1	−74.2 (4)	C13—C12—C17—C16	−0.6 (7)
O4—C4—C5—O5	−55.2 (3)	C11—C12—C17—C16	179.2 (4)
C3—C4—C5—O5	−169.1 (3)	C15—C16—C17—C12	−0.9 (8)
O4—C4—C5—C6	62.6 (3)	C1—C2—O2—C18	69.7 (4)
C3—C4—C5—C6	−51.2 (3)	C3—C2—O2—C18	−173.3 (3)
O4—C4—C5—C7	−173.0 (2)	C2—O2—C18—C19	−176.6 (3)
C3—C4—C5—C7	73.1 (3)	O2—C18—C19—C20	57.7 (6)
C1—O1—C6—C5	47.3 (4)	O2—C18—C19—C24	−121.8 (4)
O5—C5—C6—O1	70.5 (4)	C24—C19—C20—C21	−0.8 (9)
C7—C5—C6—O1	−169.8 (3)	C18—C19—C20—C21	179.7 (6)
C4—C5—C6—O1	−47.5 (4)	C19—C20—C21—C22	−0.7 (12)
O5—C5—C7—O7	−67.3 (4)	C20—C21—C22—C23	1.8 (12)
C6—C5—C7—O7	172.0 (3)	C21—C22—C23—C24	−1.4 (11)
C4—C5—C7—O7	51.7 (4)	C20—C19—C24—C23	1.1 (8)
O5—C5—C7—C8	51.2 (4)	C18—C19—C24—C23	−179.3 (5)
C6—C5—C7—C8	−69.5 (4)	C22—C23—C24—C19	−0.1 (9)
C4—C5—C7—C8	170.2 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O5—H5···O7^i	0.82	2.14	2.879 (3)	150.5
O7—H7···O8^ii	0.82	2.34	3.136 (5)	164.2

Symmetry codes: (i) x+1/2, −y+3/2, −z; (ii) x−1/2, −y+3/2, −z.