N,N,N′,N′-Tetra­methyl­strept­amine 2,4,6-orthoformate

In the title compound, rac-(1s,3s,5R,6r,7S,8R,9S)-8,9-bis­(di­methyl­amino)-2,4,10-trioxatri­cyclo­[3.3.1.1^3,7]­decan-6-ol, C₁₁H₂₀N₂O₄, an intramolecular hydrogen bond with H...N = 2.09 (2) Å is observed between the hydroxy group and one of the di­methyl­amino groups; this hydrogen bond is appreciably non-linear (146° at H). There is a short H...N contact of 2.61 (2) Å from the same hydroxy H atom to the other N atom.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.036
• wR factor = 0.101
• Data-to-parameter ratio = 16.0

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

We have studied the reactions of a number of derivatives of the synaxial diaminoalcohol (1) (Beckmann, 1998; Dean, 2000). The system is of interest in the context of enzyme mechanism and efficiency because of the close and fixed geometrical relationship between the two amino groups and the axial oxygen centre. The interatomic distances between these centres are of the order of 2.8 Å, typical of the distances observed between centres involved in intramolecular hydrogen bonds, and this might be expected to favour proton transfer catalysis when an in-flight proton can be stabilized by interactions with two (perhaps even all three) centres. The acetal (2) (Brown & Kirby, 1997) is indeed one of three dialkyl acetals of benzaldehyde shown to be hydrolyzed with intramolecular general acid catalysis (2). The detailed geometry of the system, and in particular the properties of any hydrogen bonds present, is thus of particular interest. We report here the crystal and molecular structure of (1), and in the following paper (Beckmann et al., 2003) the structure of its hydrochloride, which shows a different pattern of hydrogen bonding.

The diaminoalcohol (1) has an intramolecular O—H···N bond hydrogen bond between the alcohol OH group and one of the dimethylamino groups, which prevents the molecule from displaying more than approximate mirror symmetry. The hydrogen bond is not linear (the angle O—H···N is 146°) and the proton is displaced slightly in the direction of the second nitrogen centre [N2···H = 2.61 (2) Å and N2···O = 3.018 (1) Å]. But to all intents and purposes this is a normal three-centre hydrogen bond. The dimensions involving the N atoms (Table 1) are not significantly affected by the hydrogen bond.

Two weak C—H···O contacts (Table 2) link the molecules to form columns of molecules parallel to [110] (Fig. 2).

S2. Experimental

Crystals of compound (1) (Brown & Kirby, 1997) were grown from a saturated solution in toluene.

S3. Refinement

The H atom of the OH group was identified in a difference synthesis and refined freely. Methyl H atoms were similarly identified, the methyl groups then idealized (C—H = 0.98 Å, all angles 109.5°) and refined as rigid groups allowed to rotate but not tip. Other H atoms were included using a riding model with fixed C—H bond lengths of 1.00 Å; U_iso(H) values were fixed at 1.2U_eq of the parent atom.

Computing details

Data collection: XSCANS (Fait, 1991); cell refinement: XSCANS; data reduction: XSCANS; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XP (Siemens, 1994); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The cation of the title compound in the crystal. Ellipsoids represent 50% probability levels. H-atom radii are arbitrary.
	Fig. 2. Two columns of molecules associated by C—H···O interactions (thick dashed bonds). The view direction is perpendicular to the ab plane.

rac-(1 s,3 s,5R,6r,7S,8R,9S)-8,9-bis(dimethylamino)- 2,4,10-trioxatricyclo[3.3.1.1^3,7]decan-6-ol

Crystal data

C11H20N2O4	Z = 2
Mr = 244.29	F(000) = 264
Triclinic, P1	Dx = 1.416 Mg m^−3
a = 6.9344 (8) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.5439 (10) Å	Cell parameters from 62 reflections
c = 12.1650 (16) Å	θ = 3.5–12.5°
α = 100.386 (10)°	µ = 0.11 mm^−1
β = 104.367 (8)°	T = 173 K
γ = 105.528 (6)°	Lath, colourless
V = 572.85 (13) Å^3	0.60 × 0.40 × 0.20 mm

Data collection

Siemens P4 diffractometer	Rint = 0.016
Radiation source: fine-focus sealed tube	θmax = 27.5°, θmin = 3.2°
Graphite monochromator	h = −8→8
ω scans	k = −9→9
2719 measured reflections	l = 0→15
2598 independent reflections	3 standard reflections every 297 reflections
1931 reflections with I > 2σ(I)	intensity decay: none

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)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.101	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0587P)^2 + 0.0004P] where P = (Fo^2 + 2Fc^2)/3
2598 reflections	(Δ/σ)max < 0.001
162 parameters	Δρmax = 0.31 e Å^−3
0 restraints	Δρmin = −0.19 e Å^−3

Special details

Experimental. rac-(1S,3S,5R,6R,7S,8R,9S)-8,9-bis(dimethylamino)- 2,4,10-trioxatricyclo[3.3.1.1^3,7]decan-6-ol

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.

Non-bonded distances:

2.6140 (0.0212) N2 - H01 3.0184 (0.0014) N2 - O1 3.1620 (0.0015) N1 - N2 2.6279 (0.0017) C8 - C9 2.5426 (0.0018) C9 - C6 2.5761 (0.0017) C8 - C6

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
C1	0.6413 (2)	0.92014 (17)	0.32913 (11)	0.0230 (3)
H1	0.7133	1.0037	0.4112	0.028*
C3	0.6173 (2)	0.90092 (18)	0.13162 (11)	0.0264 (3)
H3	0.6753	0.9718	0.0787	0.032*
C5	0.3007 (2)	0.76233 (17)	0.17003 (10)	0.0206 (3)
H5	0.1461	0.7425	0.1455	0.025*
C6	0.4034 (2)	0.88180 (17)	0.29840 (11)	0.0216 (3)
H6	0.3783	1.0071	0.3039	0.026*
C7	0.57880 (19)	0.61427 (17)	0.18939 (10)	0.0191 (3)
H7	0.6126	0.4928	0.1767	0.023*
C8	0.33725 (18)	0.56832 (16)	0.14662 (10)	0.0180 (3)
H8	0.2878	0.5131	0.0594	0.022*
C9	0.69525 (19)	0.73382 (17)	0.31813 (10)	0.0206 (3)
H9	0.8501	0.7671	0.3307	0.025*
C11	0.6802 (2)	0.4533 (2)	0.39120 (12)	0.0314 (3)
H11A	0.5782	0.3669	0.3172	0.038*
H11B	0.6610	0.3992	0.4567	0.038*
H11C	0.8235	0.4697	0.3879	0.038*
C12	0.7873 (2)	0.7560 (2)	0.52656 (12)	0.0326 (3)
H12A	0.7578	0.6896	0.5858	0.039*
H12B	0.7630	0.8789	0.5430	0.039*
H12C	0.9344	0.7777	0.5293	0.039*
C13	0.0093 (2)	0.4228 (2)	0.18533 (12)	0.0294 (3)
H13A	0.0113	0.5441	0.2319	0.035*
H13B	−0.0619	0.3180	0.2136	0.035*
H13C	−0.0664	0.4042	0.1024	0.035*
C14	0.2128 (2)	0.23498 (18)	0.13637 (13)	0.0297 (3)
H14A	0.1271	0.2038	0.0538	0.036*
H14B	0.1481	0.1412	0.1740	0.036*
H14C	0.3549	0.2324	0.1404	0.036*
N1	0.64703 (16)	0.63870 (15)	0.40877 (9)	0.0220 (2)
N2	0.22536 (16)	0.42613 (14)	0.19757 (9)	0.0194 (2)
O2	0.71639 (15)	1.01568 (12)	0.24746 (8)	0.0282 (2)
O4	0.39874 (15)	0.86840 (12)	0.09821 (8)	0.0258 (2)
O10	0.66200 (14)	0.72883 (12)	0.11707 (8)	0.0247 (2)
O1	0.31852 (15)	0.79525 (13)	0.37780 (8)	0.0244 (2)
H01	0.372 (3)	0.711 (3)	0.3868 (18)	0.062 (6)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0279 (7)	0.0185 (6)	0.0208 (6)	0.0027 (5)	0.0096 (5)	0.0054 (5)
C3	0.0359 (7)	0.0214 (6)	0.0251 (7)	0.0069 (5)	0.0147 (6)	0.0103 (5)
C5	0.0252 (6)	0.0200 (6)	0.0207 (6)	0.0095 (5)	0.0092 (5)	0.0095 (5)
C6	0.0308 (7)	0.0167 (5)	0.0212 (6)	0.0101 (5)	0.0118 (5)	0.0059 (5)
C7	0.0237 (6)	0.0187 (6)	0.0199 (6)	0.0081 (5)	0.0115 (5)	0.0085 (5)
C8	0.0220 (6)	0.0166 (5)	0.0153 (5)	0.0068 (5)	0.0052 (5)	0.0046 (4)
C9	0.0186 (6)	0.0220 (6)	0.0208 (6)	0.0046 (5)	0.0073 (5)	0.0065 (5)
C11	0.0403 (8)	0.0321 (7)	0.0271 (7)	0.0147 (6)	0.0109 (6)	0.0157 (6)
C12	0.0324 (8)	0.0398 (8)	0.0211 (7)	0.0094 (6)	0.0040 (6)	0.0067 (6)
C13	0.0228 (7)	0.0292 (7)	0.0345 (7)	0.0056 (5)	0.0082 (6)	0.0095 (6)
C14	0.0375 (8)	0.0188 (6)	0.0314 (7)	0.0074 (5)	0.0104 (6)	0.0066 (5)
N1	0.0211 (5)	0.0270 (6)	0.0182 (5)	0.0069 (4)	0.0056 (4)	0.0090 (4)
N2	0.0200 (5)	0.0170 (5)	0.0214 (5)	0.0052 (4)	0.0071 (4)	0.0066 (4)
O2	0.0359 (5)	0.0189 (4)	0.0278 (5)	0.0010 (4)	0.0138 (4)	0.0081 (4)
O4	0.0361 (5)	0.0233 (5)	0.0240 (5)	0.0119 (4)	0.0119 (4)	0.0140 (4)
O10	0.0323 (5)	0.0241 (5)	0.0251 (5)	0.0096 (4)	0.0179 (4)	0.0112 (4)
O1	0.0307 (5)	0.0254 (5)	0.0236 (5)	0.0121 (4)	0.0147 (4)	0.0089 (4)

Geometric parameters (Å, º)

C1—O2	1.4464 (14)	C9—N1	1.4772 (15)
C1—C6	1.5308 (18)	C9—H9	1.0000
C1—C9	1.5403 (17)	C11—N1	1.4639 (17)
C1—H1	1.0000	C11—H11A	0.9800
C3—O2	1.4030 (16)	C11—H11B	0.9800
C3—O10	1.4045 (15)	C11—H11C	0.9800
C3—O4	1.4076 (16)	C12—N1	1.4740 (17)
C3—H3	1.0000	C12—H12A	0.9800
C5—O4	1.4566 (14)	C12—H12B	0.9800
C5—C6	1.5346 (17)	C12—H12C	0.9800
C5—C8	1.5401 (16)	C13—N2	1.4613 (16)
C5—H5	1.0000	C13—H13A	0.9800
C6—O1	1.4176 (15)	C13—H13B	0.9800
C6—H6	1.0000	C13—H13C	0.9800
C7—O10	1.4536 (14)	C14—N2	1.4680 (16)
C7—C8	1.5454 (16)	C14—H14A	0.9800
C7—C9	1.5464 (17)	C14—H14B	0.9800
C7—H7	1.0000	C14—H14C	0.9800
C8—N2	1.4729 (14)	O1—H01	0.83 (2)
C8—H8	1.0000
O2—C1—C6	108.41 (10)	C1—C9—C7	106.12 (10)
O2—C1—C9	107.94 (10)	N1—C9—H9	107.9
C6—C1—C9	111.76 (10)	C1—C9—H9	107.9
O2—C1—H1	109.6	C7—C9—H9	107.9
C6—C1—H1	109.6	N1—C11—H11A	109.5
C9—C1—H1	109.6	N1—C11—H11B	109.5
O2—C3—O10	111.25 (10)	H11A—C11—H11B	109.5
O2—C3—O4	110.92 (10)	N1—C11—H11C	109.5
O10—C3—O4	111.48 (10)	H11A—C11—H11C	109.5
O2—C3—H3	107.7	H11B—C11—H11C	109.5
O10—C3—H3	107.7	N1—C12—H12A	109.5
O4—C3—H3	107.7	N1—C12—H12B	109.5
O4—C5—C6	107.38 (9)	H12A—C12—H12B	109.5
O4—C5—C8	106.15 (9)	N1—C12—H12C	109.5
C6—C5—C8	113.83 (10)	H12A—C12—H12C	109.5
O4—C5—H5	109.8	H12B—C12—H12C	109.5
C6—C5—H5	109.8	N2—C13—H13A	109.5
C8—C5—H5	109.8	N2—C13—H13B	109.5
O1—C6—C1	111.97 (10)	H13A—C13—H13B	109.5
O1—C6—C5	113.04 (10)	N2—C13—H13C	109.5
C1—C6—C5	107.82 (10)	H13A—C13—H13C	109.5
O1—C6—H6	107.9	H13B—C13—H13C	109.5
C1—C6—H6	107.9	N2—C14—H14A	109.5
C5—C6—H6	107.9	N2—C14—H14B	109.5
O10—C7—C8	106.35 (9)	H14A—C14—H14B	109.5
O10—C7—C9	105.68 (9)	N2—C14—H14C	109.5
C8—C7—C9	116.41 (10)	H14A—C14—H14C	109.5
O10—C7—H7	109.4	H14B—C14—H14C	109.5
C8—C7—H7	109.4	C11—N1—C12	107.41 (10)
C9—C7—H7	109.4	C11—N1—C9	111.14 (10)
N2—C8—C5	115.59 (10)	C12—N1—C9	110.08 (10)
N2—C8—C7	113.06 (9)	C13—N2—C14	106.91 (10)
C5—C8—C7	105.67 (9)	C13—N2—C8	112.89 (9)
N2—C8—H8	107.4	C14—N2—C8	109.32 (10)
C5—C8—H8	107.4	C3—O2—C1	110.54 (9)
C7—C8—H8	107.4	C3—O4—C5	111.23 (9)
N1—C9—C1	111.41 (10)	C3—O10—C7	111.37 (9)
N1—C9—C7	115.34 (10)	C6—O1—H01	105.6 (14)
O2—C1—C6—O1	−177.51 (9)	O10—C7—C9—C1	60.49 (11)
C9—C1—C6—O1	63.65 (13)	C8—C7—C9—C1	−57.27 (13)
O2—C1—C6—C5	57.54 (12)	C1—C9—N1—C11	174.75 (10)
C9—C1—C6—C5	−61.30 (12)	C7—C9—N1—C11	53.70 (14)
O4—C5—C6—O1	178.93 (9)	C1—C9—N1—C12	−66.39 (13)
C8—C5—C6—O1	−63.89 (14)	C7—C9—N1—C12	172.57 (10)
O4—C5—C6—C1	−56.76 (12)	C5—C8—N2—C13	41.44 (14)
C8—C5—C6—C1	60.43 (13)	C7—C8—N2—C13	163.41 (10)
O4—C5—C8—N2	−171.75 (9)	C5—C8—N2—C14	160.30 (10)
C6—C5—C8—N2	70.35 (13)	C7—C8—N2—C14	−77.74 (12)
O4—C5—C8—C7	62.42 (11)	O10—C3—O2—C1	−61.52 (13)
C6—C5—C8—C7	−55.48 (13)	O4—C3—O2—C1	63.19 (12)
O10—C7—C8—N2	170.35 (9)	C6—C1—O2—C3	−60.45 (12)
C9—C7—C8—N2	−72.25 (13)	C9—C1—O2—C3	60.78 (12)
O10—C7—C8—C5	−62.27 (11)	O2—C3—O4—C5	−63.43 (12)
C9—C7—C8—C5	55.13 (12)	O10—C3—O4—C5	61.14 (12)
O2—C1—C9—N1	173.10 (9)	C6—C5—O4—C3	59.94 (12)
C6—C1—C9—N1	−67.77 (12)	C8—C5—O4—C3	−62.16 (12)
O2—C1—C9—C7	−60.60 (12)	O2—C3—O10—C7	63.46 (13)
C6—C1—C9—C7	58.52 (12)	O4—C3—O10—C7	−60.93 (12)
O10—C7—C9—N1	−175.63 (9)	C8—C7—O10—C3	61.70 (12)
C8—C7—C9—N1	66.60 (13)	C9—C7—O10—C3	−62.62 (12)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H01···N1	0.83 (2)	2.09 (2)	2.8109 (15)	145.8 (19)
C13—H13B···O2^i	0.98	2.55	3.5198 (16)	170
C3—H3···O4^ii	1.00	2.66	3.5442 (16)	148

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