A synthetic intermediate of enantiopure N-protected β-hydroxy­valine, (2R)-2-[N-(tert-butoxy­carbonyl)­amino]-3-methylbutane­-1,3-diol

Crystals of the title compound [systematic name: (2R)-tert-butyl N-(1,3-dihydroxy-3-methyl-2-butyl)carbamate], C₁₀H₂₁NO₄, were successfully grown from an ethyl ­acetate solution. There is one independent mol­ecule in the asymmetric unit. The urethane linkage, –O—CO—NH–, is a cis conformer and the mol­ecules are linked into a dimer by two N—H...O=C hydrogen bonds. The dimers are connected together by O—H...O hydrogen bonds in which four hydroxy groups are involved.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.010 Å
• R factor = 0.085
• wR factor = 0.244
• Data-to-parameter ratio = 9.9

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT201_ALERT_2_B Isotropic non-H Atoms in Main Residue(s) .......          5

Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.98
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...         10

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           68.12
           From the CIF: _reflns_number_total               1318
           Count of symmetry unique reflns         1346
           Completeness (_total/calc)             97.92%
           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

   0 ALERT level A = In general: serious problem
   1 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
   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

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Computing details

Data collection: RAPID-AUTO (RIGAKU/MSC & Rigaku Corporation, 2003); cell refinement: RAPID-AUTO; data reduction: CrystalStructure (RIGAKU/MSC & Rigaku Corporation, 2003); program(s) used to solve structure: SIR2002 (Burla et al., 2003); program(s) used to refine structure: CRYSTALS (Watkin et al., 1996); molecular graphics: ORTEP (Johnson, 1965); software used to prepare material for publication: CrystalStructure.

(2R)-2-N-(tert-Butoxycarbonyl)-Amino-3-Methyl-1,3-Butanediol

Crystal data

C10H21NO4	? # Insert any comments here.
Mr = 219.28	Dx = 1.162 Mg m^−3
Orthorhombic, P21212	Cu Kα radiation, λ = 1.54180 Å
Hall symbol: P 2 2ab	Cell parameters from 8702 reflections
a = 9.833 (8) Å	θ = 4.5–66.6°
b = 18.994 (17) Å	µ = 0.74 mm^−1
c = 6.713 (8) Å	T = 173 K
V = 1254 (2) Å^3	Prism, colorless
Z = 4	0.25 × 0.25 × 0.05 mm
F(000) = 480.00

Data collection

Rigaku R-AXIS RAPID diffractometer	965 reflections with F^2 > 2σ(F^2)
Detector resolution: 10.00 pixels mm^-1	Rint = 0.045
ω scans	θmax = 68.1°
Absorption correction: part of the refinement model (ΔF) (DIFABS; Walker & Stuart, 1983)	h = −11→11
Tmin = 0.765, Tmax = 0.964	k = −22→22
10309 measured reflections	l = −8→8
1318 independent reflections

Refinement

Refinement on F^2	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.085	w = 1/[0.007Fo^2 + σ(Fo^2)]/(4Fo^2)
wR(F^2) = 0.244	(Δ/σ)max < 0.001
S = 1.07	Δρmax = 0.59 e Å^−3
1318 reflections	Δρmin = −0.43 e Å^−3
133 parameters

Special details

Experimental. ? #Insert any special details here.

Refinement. Refinement using all reflections. The weighted R-factor (wR) and goodness of fit (S) are based on F². R-factor (gt) are based on F. The threshold expression of F² > 2.0 σ(F²) is used only for calculating R-factor (gt).

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

	x	y	z	Uiso*/Ueq	Occ. (<1)
O11	0.2590 (4)	0.3800 (2)	0.1781 (7)	0.0373 (11)
O12	0.4667 (4)	0.4073 (2)	0.0500 (7)	0.0350 (11)
O21	0.0758 (5)	0.5598 (3)	−0.0216 (7)	0.0577 (15)
O22	0.0987 (5)	0.5531 (2)	0.5719 (6)	0.0406 (15)
N21	0.3249 (5)	0.4916 (2)	0.1668 (8)	0.0307 (12)
C11	0.2709 (7)	0.3028 (3)	0.1328 (9)	0.0420 (18)
C12	0.2795 (8)	0.2936 (4)	−0.0924 (12)	0.054 (2)*
C13	0.3893 (8)	0.2718 (4)	0.2493 (12)	0.0563 (19)*
C14	0.1369 (8)	0.2765 (4)	0.2141 (13)	0.060 (2)*
C15	0.3591 (6)	0.4247 (3)	0.1266 (9)	0.0298 (14)
C21	0.2033 (6)	0.5172 (3)	0.2668 (8)	0.0264 (13)
C22	0.1481 (7)	0.5802 (3)	0.1530 (10)	0.0378 (17)
C23	0.2286 (6)	0.5328 (3)	0.4932 (10)	0.0332 (15)
C24	0.2777 (7)	0.4678 (4)	0.6004 (10)	0.0486 (19)*
C25	0.3257 (7)	0.5935 (4)	0.5209 (12)	0.0518 (19)*
H1	0.3877	0.5265	0.1246	0.037*
H2	0.1905	0.2881	−0.1452	0.065*
H3	0.3322	0.2530	−0.1221	0.065*
H4	0.3214	0.3337	−0.1508	0.065*
H5	0.4699	0.2749	0.1718	0.068*
H6	0.3710	0.2239	0.2796	0.068*
H7	0.4014	0.2970	0.3703	0.068*
H8	0.1454	0.2638	0.3504	0.072*
H9	0.1085	0.2363	0.1406	0.073*
H10	0.0699	0.3122	0.2007	0.072*
H11	0.1370	0.4810	0.2590	0.032*
H12	0.2221	0.6097	0.1168	0.045*
H13	0.0879	0.6054	0.2376	0.045*
H14	0.3315	0.4817	0.7113	0.058*
H15	0.3309	0.4401	0.5120	0.058*
H16	0.2027	0.4407	0.6454	0.059*
H17	0.3225	0.6243	0.4095	0.062*
H18	0.4157	0.5760	0.5348	0.062*
H19	0.3013	0.6186	0.6379	0.062*
H211	0.0779	0.5202	−0.0528	0.069*	0.50
H212	0.1247	0.5662	−0.1189	0.069*	0.50
H221	0.0380	0.5213	0.5766	0.049*	0.50
H222	0.1106	0.5772	0.6719	0.049*	0.50

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O11	0.028 (2)	0.031 (2)	0.053 (3)	−0.0038 (17)	0.007 (2)	−0.004 (2)
O12	0.025 (2)	0.034 (2)	0.046 (2)	0.0022 (17)	0.005 (2)	−0.007 (2)
O21	0.068 (3)	0.076 (3)	0.029 (2)	0.009 (3)	−0.014 (3)	−0.002 (3)
O22	0.041 (2)	0.053 (3)	0.028 (2)	0.004 (2)	0.007 (2)	0.001 (2)
N21	0.025 (2)	0.027 (2)	0.040 (3)	−0.002 (2)	0.007 (2)	−0.002 (2)
C11	0.038 (4)	0.021 (3)	0.067 (4)	−0.005 (2)	−0.002 (4)	−0.001 (3)
C15	0.028 (3)	0.030 (3)	0.031 (3)	−0.001 (2)	−0.002 (3)	−0.007 (2)
C21	0.023 (3)	0.029 (3)	0.027 (3)	−0.004 (2)	0.004 (2)	−0.008 (2)
C22	0.034 (3)	0.040 (3)	0.039 (4)	0.004 (3)	0.003 (3)	−0.004 (3)
C23	0.025 (3)	0.041 (3)	0.033 (3)	0.000 (2)	0.001 (3)	−0.009 (3)

Geometric parameters (Å, º)

O11—C11	1.503 (7)	C12—H2	0.9500
O11—C15	1.345 (7)	C12—H3	0.9500
O12—C15	1.222 (7)	C12—H4	0.9500
O21—C22	1.425 (8)	C13—H5	0.9500
O22—C23	1.436 (7)	C13—H6	0.9500
N21—C15	1.341 (7)	C13—H7	0.9501
N21—C21	1.455 (7)	C14—H8	0.9500
C11—C12	1.524 (10)	C14—H9	0.9500
C11—C13	1.521 (10)	C14—H10	0.9499
C11—C14	1.511 (11)	C21—H11	0.9500
C21—C22	1.519 (8)	C22—H12	0.9501
C21—C23	1.569 (9)	C22—H13	0.9500
C23—C24	1.507 (9)	C24—H14	0.9500
C23—C25	1.509 (9)	C24—H15	0.9500
O21—H211	0.7809	C24—H16	0.9500
O21—H212	0.8201	C25—H17	0.9499
O22—H221	0.8499	C25—H18	0.9500
O22—H222	0.8203	C25—H19	0.9501
N21—H1	0.9500
O11—C11—C12	108.5 (5)	C11—C12—H4	109.9408
O11—C11—C13	109.5 (5)	C11—C13—H5	109.4309
O11—C11—C14	100.5 (5)	C11—C13—H6	109.6139
C15—O11—C11	120.5 (5)	C11—C13—H7	109.8789
O11—C15—O12	124.8 (5)	C11—C14—H8	110.7796
O11—C15—N21	111.2 (5)	C11—C14—H9	109.5004
O12—C15—N21	124.0 (5)	C11—C14—H10	109.5226
O21—C22—C21	112.2 (5)	H3—C12—H2	109.5557
O22—C23—C21	105.4 (4)	H4—C12—H2	109.4692
O22—C23—C24	109.3 (5)	H4—C12—H3	109.1384
O22—C23—C25	108.2 (5)	H6—C13—H5	109.5299
C21—N21—C15	128.0 (5)	H7—C13—H5	109.4729
N21—C21—C22	109.0 (5)	H7—C13—H6	108.8999
N21—C21—C23	112.3 (4)	H9—C14—H8	108.7911
C13—C11—C12	115.0 (6)	H10—C14—H8	109.4732
C14—C11—C12	111.6 (6)	H10—C14—H9	108.7400
C14—C11—C13	110.7 (6)	H11—C21—C22	107.2776
C23—C21—C22	113.3 (5)	C21—C22—H12	108.6028
C21—C23—C24	111.1 (5)	C21—C22—H13	108.6153
C21—C23—C25	111.3 (5)	H11—C21—C23	107.3909
C25—C23—C24	111.4 (5)	H13—C22—H12	109.4536
H211—O21—C22	117.9598	C23—C24—H15	109.3269
O21—C22—H12	109.3955	C23—C24—H16	110.3492
O21—C22—H13	108.5086	C23—C24—H14	109.0249
H212—O21—C22	108.8235	C23—C25—H17	110.6347
H212—O21—H211	84.9642	C23—C25—H18	109.4523
H221—O22—C23	116.6026	C23—C25—H19	109.0207
H222—O22—C23	108.9098	H15—C24—H14	109.6782
H222—O22—H221	117.7051	H16—C24—H14	109.4715
H1—N21—C15	116.0007	H16—C24—H15	108.9776
H1—N21—C21	115.9656	H18—C25—H17	108.9001
N21—C21—H11	107.2022	H19—C25—H17	109.4741
C11—C12—H2	109.3659	H19—C25—H18	109.3409
C11—C12—H3	109.3572
C15—O11—C11—C12	−62.0 (7)	N21—C21—C22—O21	77.9 (6)
C15—O11—C11—C13	64.3 (7)	C23—C21—C22—O21	−156.2 (5)
C15—O11—C11—C14	−179.2 (5)	N21—C21—C23—O22	−176.5 (4)
C11—O11—C15—O12	−3.3 (9)	N21—C21—C23—C24	−58.3 (6)
C11—O11—C15—N21	175.5 (5)	N21—C21—C23—C25	66.4 (6)
C21—N21—C15—O11	4.8 (8)	C22—C21—C23—O22	59.4 (6)
C21—N21—C15—O12	−176.4 (6)	C22—C21—C23—C24	177.6 (5)
C15—N21—C21—C22	−135.8 (6)	C22—C21—C23—C25	−57.6 (6)
C15—N21—C21—C23	97.8 (6)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N21—H1···O12^i	0.95	1.97	2.916 (6)	174
O21—H211···O21^ii	0.78	2.15	2.717 (8)	129
O22—H222···O21^iii	0.82	2.11	2.742 (6)	133
O21—H212···O22^iv	0.82	2.11	2.742 (6)	134
O22—H221···O22^ii	0.85	1.95	2.799 (6)	177

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