tert-Butyl N-hydr­oxy-N-[(1S*,2R*)-2-(1-naphth­yl)cyclo­pent-3-en-1-yl]carbamate

Alan J Lough; Ben P Machin; William Tam

doi:10.1107/S1600536809020315

. 2009 Jun 6;65(Pt 7):o1481. doi: 10.1107/S1600536809020315

tert-Butyl N-hydroxy-N-[(1S,2R)-2-(1-naphthyl)cyclopent-3-en-1-yl]carbamate

Alan J Lough ^a,^*, Ben P Machin ^b, William Tam ^b

PMCID: PMC2969270 PMID: 21582783

Abstract

The relative stereochemistry of the title compound, C₂₀H₂₃NO₃, was established by X-ray analysis. The asymmetric unit contains two independent molecules. In the crystal structure, each type of molecule forms a centrosymmetric dimer via pairs of intermolecular O—H⋯O hydrogen bonds, resulting in an R ₂ ²(10) loop in each case.

Related literature

For hydrogen-bond graph sets, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₀H₂₃NO₃
M _r = 325.39
Triclinic,
a = 8.4710 (5) Å
b = 8.4880 (4) Å
c = 26.1836 (12) Å
α = 95.980 (3)°
β = 95.419 (2)°
γ = 111.960 (2)°
V = 1718.32 (15) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 150 K
0.22 × 0.18 × 0.14 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (SORTAV; Blessing, 1995 ▶) T _min = 0.918, T _max = 0.989
10769 measured reflections
6622 independent reflections
4089 reflections with I > 2σ(I)
R _int = 0.035

Refinement

R[F ² > 2σ(F ²)] = 0.057
wR(F ²) = 0.167
S = 1.10
6622 reflections
448 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.33 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Data collection: COLLECT (Nonius, 2002 ▶); cell refinement: DENZO-SMN (Otwinowski & Minor, 1997 ▶); data reduction: DENZO-SMN; program(s) used to solve structure: SIR92 (Altomare et al., 1994 ▶); program(s) used to refine structure: SHELXTL (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809020315/hb2980sup1.cif

e-65-o1481-sup1.cif^{(27.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809020315/hb2980Isup2.hkl

e-65-o1481-Isup2.hkl^{(324.1KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1A—H1OA⋯O3Aⁱ	0.96 (4)	1.75 (4)	2.689 (3)	165 (3)
O1B—H1OB⋯O3Bⁱⁱ	0.88 (3)	1.84 (4)	2.714 (3)	179 (4)

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

The authors wish to acknowledge NSERC Canada and the University of Toronto for funding.

supplementary crystallographic information

Comment

We have recently studied the addition of aryl groups to a 3-aza-2-oxabicyclo[2.2.1]hept-5-ene system using a [Rh(COD)Cl]₂ (COD = cyclooctadiene) catalyst. The reaction produces two stereoisomers, the absolute stereochemistry of the title major isomer,(I), was determined by single-crystal X-ray diffraction.

The asymmetric unit of (I) contains two independent molecules [A and B] which are shown in Figs 1 and 2. In the crystal structure, each type of molecule is linked into a centrosymmetric dimer via intermolecular O—H···O hydrogen bonds (Fig. 3). Each dimer forms a R₂²(10) graph set (Bernstein et al., 1995).

Experimental

3-aza-2-oxabicyclo[2.2.1]hept-5-ene (I) (see Fig. 4) (99.4 mg, 0.504 mmol) and 1-napthalene boronic acid (103.1 mg, 0.599 mmol) were weighed into a dry vial and purged with nitrogen. Dried MeOH (2.3 ml) was measured out into a dry vial and purged with nitrogen. Inside an inert atmosphere (Ar) dry box, [Rh(COD)Cl]₂ (15.6 mg, 0.031 mmol) and (±)-BINAP (41.0 mg, 0.066 mmol) were weighed out and dissolved in methanol (1.0 ml), and stirred for 30 minutes. NaHCO₃ (85.4 mg, 1.03 mmol) was added to the vial containing the bicyclic alkene and dissolved in MeOH (1.3 ml) and transferred to the vial with the catalyst. The reaction was heated to 333 K and stirred overnight. The crude product was purified using column chromatography (EtOAc:hexanes = 1:4) to give (II) as the major stereoisomer as an off white solid (58.1 mg, 0.179 mmol, 36%). Colourless blocks of (I) were grown from a solution of the title compound in dichloromethane/hexanes.