Synthesis and Crystal Structure Characterization of (6 R,7a S)-1,1-Diphenyl-6-(4-vinylbenzyloxy)tetrahydropyrrolo[1,2-c]oxazol-3(1H)-one

Article abstract of DOI:10.1080/15421406.2015.1011467

The title compound, (6R,7aS)-1,1-Diphenyl-6-(4-vinylbenzyloxy)tetrahydropyrrolo[1,2-c]oxazol-3(1H)-one, was synthesized and characterized by ¹H and ¹³C NMR and high-resolution mass spectrometry (HRMS). Its molecular configuration was investigated by X-ray crystallography. The crystal structure is devoid of any classical hydrogen bonding, and molecules are linked by weak CH.O contacts. In the 4-vinylbenzyloxy group, the three H atoms and one C atom are disordered over two sets of sites, with site occupancy factors of 0.75 and 0.25.

Full text of DOI:10.1080/15421406.2015.1011467

Molecular Crystals and Liquid Crystals
ISSN: 1542-1406 (Print) 1563-5287 (Online) Journal homepage: http://www.tandfonline.com/loi/gmcl20
Synthesis and Crystal Structure
Characterization of (6R,7aS)-1,1-Diphenyl-6-
(4-vinylbenzyloxy)tetrahydropyrrolo[1,2-
c]oxazol-3(1H)-one
Can Zhang, Gong-jian Pan & Ai-bao Xia
To cite this article: Can Zhang, Gong-jian Pan & Ai-bao Xia (2015) Synthesis and Crystal
Structure Characterization of (6R,7aS)-1,1-Diphenyl-6-(4-vinylbenzyloxy)tetrahydropyrrolo[1,2-
c]oxazol-3(1H)-one, Molecular Crystals and Liquid Crystals, 623:1, 297-304, DOI:
10.1080/15421406.2015.1011467
To link to this article: http://dx.doi.org/10.1080/15421406.2015.1011467
Published online: 21 Dec 2015.
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Date: 02 April 2016, At: 17:42

Mol. Cryst. Liq. Cryst., Vol. 623: pp. 297–304, 2015
Copyright © Taylor & Francis Group, LLC
ISSN: 1542-1406 print/1563-5287 online
DOI: 10.1080/15421406.2015.1011467
Synthesis and Crystal Structure Characterization
of (6R,7aS)-1,1-Diphenyl-6-(4-
vinylbenzyloxy)tetrahydropyrrolo[1,2-c]oxazol-
3(1H)-one
CAN ZHANG, GONG-JIAN PAN, AND AI-BAO XIA∗
Catalytic Hydrogenation Research Center, State Key Laboratory Breeding Base
of Green Chemistry-Synthesis Technology, Zhejiang University of Technology,
Hangzhou, China
The title compound, (6R,7aS)-1,1-Diphenyl-6-(4-vinylbenzyloxy)tetrahydropyrrolo
1
[1,2-c]oxazol -3(1H)-one, was synthesized and characterized by H and 13C NMR
and high-resolution mass spectrometry (HRMS). Its molecular configuration was in-
vestigated by X-ray crystallography. The crystal structure is devoid of any classical
. . .
hydrogen bonding, and molecules are linked by weak C
H
O contacts. In the 4-
vinylbenzyloxy group, the three H atoms and one C atom are disordered over two sets
of sites, with site occupancy factors of 0.75 and 0.25.
Keywords Chirality; Jørgensen–Hayashi catalyst; single crystal; X-ray diffraction
Introduction
(S)-α, α-Diarylprolinol silyl ethers, also known as Jørgensen–Hayashi catalysts, were
proven to be promising organocatalysts [1]. Therefore, novel synthetic routes to such new
kind of compounds are of interest. In this paper, the title compound, as an intermediate to
some functional Jørgensen–Hayashi catalysts, was synthesized. Furthermore, the title com-
pound, (6R,7aS)-1,1-Diphenyl-6-(4-utetrahydropyrrolo[1,2-c]oxazol-3(1H)-one, (Fig. 1),
was characterized by H and 13C NMR, and HRMS spectroscopy. Its crystal structure was
investigated by X-ray single-crystal diffraction analysis.
Experimental
1H and 13C NMR were recorded in CDCl3 on Bruker AVANCE III (500 MHz for 1H NMR
and 125 MHz for 13C NMR). Proton chemical shifts (δ) are relative to tetramethylsilane
∗Address correspondence to Ai-Bao Xia, Catalytic Hydrogenation Research Center, State Key
Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Tech-
nology, Hangzhou, China. E-mail: xiaaibao@zjut.edu.cn
Color versions of one or more of the figures in the article can be found online at
www.tandfonline.com/gmcl.
297

298
C. Zhang et al.
Figure 1. Structure of the title compound.
Table 1. Crystal data and structure refinement parameters of compound 1
Parameter
Value
CCDC deposition number
Empirical formula
Formula weight
Temperature
1026620
C27 H25 N O3
411.48
273(2) K
Wavelength
0.71073 Å
Crystal system
Monoclinic
Space group
Unit cell dimensions
C 2
a = 15.279(8) Å
b = 10.115(6) Å
c = 14.709(9) Å
2165(2) Å3
a = 90◦
β = 107.785(8)◦
γ = 90◦
Volume
Z
4
Density (calculated)
Absorption coefficient
F(000)
1.263 Mg/m3
0.082 mm-1
872
Crystal size
Theta range for data collection
Index ranges
0.187 × 0.123 × 0.056 mm3
2.452 to 25.476◦.
−15 < = h < = 18, −11 < = k
< = 12, −10 < = l < = 17
5444
Reflections collected
Independent reflections
3760 [R(int) = 0.0278]
Completeness to theta = 25.242◦ 96.6%
Absorption correction
Semiempirical from equivalents
Max. and min. transmission
Refinement method
0.7456 and 0.2435
Full-matrix least-squares on F2
3760/21/289
Data/restraints/parameters
Goodness-of-fit on F2
1.050
Final R indices [I>2sigma(I)]
R indices (all data)
Absolute structure parameter
Extinction coefficient
R1 = 0.0689, wR2 = 0.1116
R1 = 0.1197, wR2 = 0.1237
1.0(10)
n/a
Largest diff. peak and hole
0.219 and −0.177 e.Å-3

Synthesis and Crystal Structure Characterization
299
Table 2. Atomic coordinates and equivalent thermal parameters of the nonhydrogen atoms
ꢀ ꢀ
(Å2). Ueq = (1/3)
i
j Uijai∗aj∗(a i .a j)
Atom
x
y
z
Ueq
Occ. (<1)
N(1)
O(1)
O(2)
O(3)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
1.0044(3)
1.0745(3)
0.9793(3)
0.8764(3)
1.0239(4)
0.9236(4)
0.9196(4)
0.8477(4)
0.8941(4)
0.9976(5)
0.7934(5)
0.8031(5)
0.8695(5)
0.8782(6)
0.8208(5)
0.7553(5)
0.7463(5)
0.8263(7)
0.8872(9)
0.8370(30)
0.8314(4)
0.7618(5)
0.6766(5)
0.6585(5)
0.7269(6)
0.8130(5)
0.9745(4)
0.9582(4)
1.0016(6)
1.0610(6)
1.0781(5)
1.0359(4)
0.3955(5)
0.5022(5)
0.3317(4)
0.5094(5)
0.4190(7)
0.2451(5)
0.3196(5)
0.4259(6)
0.5285(6)
0.5062(7)
0.5728(7)
0.7180(7)
0.7744(8)
0.9085(9)
0.9916(8)
0.9351(9)
0.8006(9)
1.1351(9)
1.1982(13)
1.2510(30)
0.2308(6)
0.1634(7)
0.1538(7)
0.2122(7)
0.2808(7)
0.2895(6)
0.1154(6)
0.0260(7)
−0.0930(7)
−0.1289(8)
−0.0430(8)
0.0775(7)
0.7640(4)
0.6667(3)
0.6133(3)
0.8919(3)
0.6811(5)
0.6514(4)
0.7402(4)
0.7298(5)
0.8050(5)
0.8230(4)
0.8950(6)
0.9031(5)
0.9762(5)
0.9834(6)
0.9193(5)
0.8473(6)
0.8390(5)
0.9259(7)
0.9966(9)
0.9550(30)
0.5762(4)
0.5963(4)
0.5308(5)
0.4447(5)
0.4233(5)
0.4883(5)
0.6743(4)
0.7379(4)
0.7553(5)
0.7075(6)
0.6443(6)
0.6277(5)
0.057(1)
0.088(2)
0.064(1)
0.080(1)
0.063(2)
0.049(2)
0.051(2)
0.063(2)
0.066(2)
0.077(2)
0.088(2)
0.067(2)
0.086(2)
0.096(2)
0.072(2)
0.089(2)
0.086(2)
0.107(3)
0.124(4)
0.131(7)
0.051(2)
0.071(2)
0.077(2)
0.078(2)
0.083(2)
0.066(2)
0.051(2)
0.068(2)
0.084(2)
0.093(3)
0.095(3)
0.075(2)
C(9)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(15ꢀ)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
0.75
0.25
(δ = 0.0) as internal standard and expressed in parts per million. Spin multiplicities are
given as s (singlet), d (doublet), t (triplet), and q (quartet) as well as b (broad). Coupling
constants (J) are given in hertz. High-resolution mass spectrometry (HRMS) data were
measured on an Agilent 6120 LC/TOF-MS with ESI source.
Synthesis of (6R,7aS)-1,1-Diphenyl-6-(4-vinylbenzyloxy)tetrahydropyrrolo[1,2-c]ox-
azol-3(1H) -one 1 Sodium hydride (1.69 g, 0.044 mmol, 4.4 eq, 60 (ω%)) was added in
a N2-filled round-bottom flask containing 30 mL dried N,N-dimethylformamide (DMF) at
room temperature with stirring for 10 min. Then, the solution of 2 [2] (3.41 g, 0.01 mmol, 1
eq) in 9 mL of dried DMF was added in 30 min at 0◦C. After an hour, 1-(chloromethyl)-4-
vinylbenzene (1.67 g, 0.011 mmol, 1.1 eq) was added slowly using a septum. The resulting

300
C. Zhang et al.
Table 3. bond lengths (A◦) for the title compound 1
Atoms
Length
Atoms
Length
N(1)-C(1)
N(1)-C(6)
N(1)-C(3)
O(1)-C(1)
O(2)-C(1)
O(2)-C(2)
O(3)-C(5)
O(3)-C(7)
C(2)-C(22)
C(2)-C(16)
C(2)-C(3)
C(3)-C(4)
C(3)-H(3)
C(4)-C(5)
C(4)-H(4A)
C(4)-H(4B)
C(5)-C(6)
C(5)-H(5)
C(6)-H(6A)
C(6)-H(6B)
C(7)-C(8)
C(7)-H(7A)
C(7)-H(7B)
C(8)-C(13)
C(8)-C(9)
C(9)-C(10)
C(9)-H(9)
C(10)-C(11)
C(10)-H(10)
C(11)-C(12)
C(11)-C(14)
C(12)-C(13)
1.361(7)
1.440(7)
1.455(7)
1.205(7)
1.350(7)
1.448(6)
1.399(6)
1.434(7)
1.510(7)
1.510(7)
1.524(7)
1.512(7)
0.9800
1.524(8)
0.9700
0.9700
1.538(8)
0.9800
0.9700
C(12)-H(12)
C(13)-H(13)
C(14)-C(15ꢀ)
C(14)-C(15)
C(14)-H(14)
C(14)-H(14ꢀ)
C(15)-H(15A)
C(15)-H(15B)
C(15’)-H(15C)
C(15’)-H(15D)
C(16)-C(17)
C(16)-C(21)
C(17)-C(18)
C(17)-H(17)
C(18)-C(19)
C(18)-H(18)
C(19)-C(20)
C(19)-H(19)
C(20)-C(21)
C(20)-H(20)
C(21)-H(21)
C(22)-C(27)
C(22)-C(23)
C(23)-C(24)
C(23)-H(23)
C(24)-C(25)
C(24)-H(24)
C(25)-C(26)
C(25)-H(25)
C(26)-C(27)
C(26)-H(26)
C(27)-H(27)
0.9300
0.9300
1.24(2)
1.328(12)
0.9601
0.9675
0.9300
0.9300
0.9300
0.9300
1.368(8)
1.372(7)
1.367(8)
0.9300
1.346(9)
0.9300
1.368(9)
0.9300
1.373(9)
0.9300
0.9700
1.478(9)
0.9700
0.9300
1.376(7)
1.376(8)
1.360(9)
0.9300
1.356(9)
0.9300
1.355(10)
0.9300
1.366(9)
0.9300
0.9700
1.356(9)
1.358(9)
1.364(10)
0.9300
1.363(9)
0.9300
1.343(10)
1.456(11)
1.369(10)
0.9300
reaction mixture was allowed to react with stirring at ambient temperature. Subsequently,
the reaction was quenched with diethyl ether (10 mL) and water (10 mL). The layers
were separated and the aqueous phase was extracted with diethyl ether several times. The
combined organic layers were washed with water, dried over anhydrous Na2SO4 and the
solvent was removed under reduced pressure. The residue was purified by silica gel column
chromatography (petroleum ether/ethyl acetate = 85:15) to afford the title compound 1
as colorless solid, yield: 18.5 g, 90%. b1H NMR (500 MHz, CDCl3): δ = 7.58−7.56
(m, 2H), 7.45−7.42 (m, 2H), 7.41−7.37 (m, 6H), 7.35−7.27 (m, 4H), 6.76−6.72 (q, J
= 11.0, 17.5 Hz, 1H), 5.81−5.78 (m, 1H), 5.31−5.28 (m, 1H), 4.90−4.93 (q, J = 5.0,
11.5 Hz, 1H), 4.48 (s, 2H), 4.18 (t, J = 5.5 Hz, 1H), 4.08−4.05(q, J = 5.5, 12.5 Hz, 1H),
3.38−3.35 (m, 1H), 1.96−1.92 (q, J = 5.0, 13.5 Hz, 1H), 1.25−1.19 (m, 1H) ppm; 13C

Synthesis and Crystal Structure Characterization
301
Table 4. Bond angles (◦) for the title compound 1
Atoms
Angle
Atoms
Angle
C(1)-N(1)-C(6)
C(1)-N(1)-C(3)
C(6)-N(1)-C(3)
C(1)-O(2)-C(2)
C(5)-O(3)-C(7)
O(1)-C(1)-O(2)
O(1)-C(1)-N(1)
O(2)-C(1)-N(1)
O(2)-C(2)-C(22)
O(2)-C(2)-C(16)
C(22)-C(2)-C(16)
O(2)-C(2)-C(3)
C(22)-C(2)-C(3)
C(16)-C(2)-C(3)
N(1)-C(3)-C(4)
N(1)-C(3)-C(2)
C(4)-C(3)-C(2)
N(1)-C(3)-H(3)
C(4)-C(3)-H(3)
C(2)-C(3)-H(3)
C(3)-C(4)-C(5)
C(3)-C(4)-H(4A)
C(5)-C(4)-H(4A)
C(3)-C(4)-H(4B)
C(5)-C(4)-H(4B)
H(4A)-C(4)-H(4B)
O(3)-C(5)-C(4)
O(3)-C(5)-C(6)
C(4)-C(5)-C(6)
O(3)-C(5)-H(5)
C(4)-C(5)-H(5)
C(6)-C(5)-H(5)
N(1)-C(6)-C(5)
N(1)-C(6)-H(6A)
C(5)-C(6)-H(6A)
N(1)-C(6)-H(6B)
C(5)-C(6)-H(6B)
H(6A)-C(6)-H(6B)
O(3)-C(7)-C(8)
O(3)-C(7)-H(7A)
C(8)-C(7)-H(7A)
O(3)-C(7)-H(7B)
C(8)-C(7)-H(7B)
118.7(5)
107.4(5)
109.4(4)
109.5(5)
112.7(5)
122.2(6)
127.4(7)
110.4(6)
106.8(4)
107.6(5)
112.5(5)
102.4(4)
113.0(5)
113.7(5)
102.4(5)
101.6(4)
118.9(5)
111.0
111.0
111.0
104.4(5)
110.9
110.9
110.9
110.9
108.9
113.0(5)
107.3(5)
104.6(5)
110.6
110.6
110.6
105.7(5)
110.6
110.6
110.6
110.6
108.7
112.3(6)
109.1
109.1
109.1
C(11)-C(12)-C(13)
C(11)-C(12)-H(12)
C(13)-C(12)-H(12)
C(8)-C(13)-C(12)
C(8)-C(13)-H(13)
C(12)-C(13)-H(13)
C(15ꢀ)-C(14)-C(11)
C(15)-C(14)-C(11)
C(15)-C(14)-H(14)
C(11)-C(14)-H(14)
C(15ꢀ)-C(14)-H(14ꢀ)
C(11)-C(14)-H(14ꢀ)
C(14)-C(15)-H(15A)
C(11)-C(14)-H(14ꢀ)
C(14)-C(15)-H(15A)
C(14)-C(15)-H(15B)
H(15A)-C(15)-H(15B)
C(14)-C(15ꢀ)-H(15C)
C(14)-C(15ꢀ)-H(15D)
H(15C)-C(15ꢀ)-H(15D)
C(17)-C(16)-C(21)
C(17)-C(16)-C(2)
C(21)-C(16)-C(2)
C(18)-C(17)-C(16)
C(18)-C(17)-H(17)
C(16)-C(17)-H(17)
C(19)-C(18)-C(17)
C(19)-C(18)-H(18)
C(17)-C(18)-H(18)
C(18)-C(19)-C(20)
C(18)-C(19)-H(19)
C(20)-C(19)-H(19)
C(19)-C(20)-C(21)
C(19)-C(20)-H(20)
C(21)-C(20)-H(20)
C(20)-C(21)-C(16)
C(20)-C(21)-H(21)
C(16)-C(21)-H(21)
C(27)-C(22)-C(23)
C(27)-C(22)-C(2)
C(23)-C(22)-C(2)
C(24)-C(23)-C(22)
C(24)-C(23)-H(23)
121.6(7)
119.2
119.2
121.7(7)
119.2
119.2
165(2)
122.9(11)
118.7
118.4
96.2
98.9
120.0
120.0
120.0
120.0
120.0
119.7
120.3
120.0
118.0(6)
120.2(5)
121.7(5)
121.3(6)
119.4
119.4
120.6(7)
119.7
119.7
119.2(7)
120.4
120.4
120.6(7)
119.7
119.7
120.4(6)
119.8
119.8
116.6(6)
120.9(5)
122.4(5)
122.0(6)
119.0
109.1
(Continued on next page)

302
C. Zhang et al.
Table 4. Bond angles (◦) for the title compound 1(Continued)
Atoms
Angle
Atoms
Angle
H(7A)-C(7)-H(7B)
C(13)-C(8)-C(9)
C(13)-C(8)-C(7)
C(9)-C(8)-C(7)
C(8)-C(9)-C(10)
C(8)-C(9)-H(9)
C(10)-C(9)-H(9)
C(11)-C(10)-C(9)
C(11)-C(10)-H(10)
C(9)-C(10)-H(10)
C(12)-C(11)-C(10)
C(12)-C(11)-C(14)
C(10)-C(11)-C(14)
107.9
C(22)-C(23)-H(23)
C(25)-C(24)-C(23)
C(25)-C(24)-H(24)
C(23)-C(24)-H(24)
C(26)-C(25)-C(24)
C(26)-C(25)-H(25)
C(24)-C(25)-H(25)
C(25)-C(26)-C(27)
C(25)-C(26)-H(26)
C(27)-C(26)-H(26)
C(26)-C(27)-C(22)
C(26)-C(27)-H(27)
C(22)-C(27)-H(27)
119.0
120.3(7)
119.8
119.8
118.9(8)
120.5
120.5
121.0(7)
119.5
119.5
121.1(7)
119.4
117.1(7)
122.0(8)
120.9(8)
120.7(8)
119.6
119.6
122.2(8)
118.9
118.9
116.7(7)
119.4(8)
123.8(8)
119.4
NMR (125 MHz, CDCl3): δ = 160.4, 143.0, 140.2, 137.4, 137.2, 136.4 (×2), 128.7 (×2),
128.5 (×2), 128.0 (×2), 127.8, 126.4 (×2), 126.1 (×2), 125.5 (×2), 114.2, 85.8, 78.4, 71.1,
67.5, 53.8, 36.2 ppm; HRMS (ESI-TOF) m/z: [M + H]+ calcd for C27H26NO3 412.1913;
found 412.1922.
Crystal Structure Analysis
The crystal structure of the title compound was solved by direct methods and was refined
anisotropically by full matrix least-squares method on F2. All H atoms were placed in their
calculated positions and included in the refinement using the riding model. A summary of
the salient crystallographic data is given in Table 1.
Figure 2. ORTEP of the molecule with thermal ellipsoids drawn at 50% probability.

Synthesis and Crystal Structure Characterization
303
Figure 3. The crystal packing of the title compound 1.
A single crystal suitable for X-ray diffraction obtained in acetonitrile and methanol
(V/V = 1:4) was colorless and block. The single crystal XRD of the crystal was collected
on a PROCESS-AUTO [3] diffractometer at 273(2) K using graphite-monochromated Mo
Kα radiation (λ = 0.71073 Å). The cell was refined on a PROCESS-AUTO [3] and the data
were reducted on a CrystalStructure [4] and corrected for absorption using multiscan [5].
The structure was solved by direct methods using SHELXS-97 and refined by a full-matrix
least-squares procedure using the program SHELXL-97 [6]. Subsequent refinements were
carried out with anisotropic thermal parameters for nonhydrogen atoms. H atoms were
placed in calculated positions with C—H = 0.96 Å (sp3), C—H = 0.93 Å (aromatic). All H
atoms included in the final cycles of refinement using a riding model, with Uiso(H) = 1.5
Ueq(sp3) or 1.2 Ueq of the carrier atoms. A molecular plot was prepared with ORTEP-3
for Windows [7]. The software used to prepare material for publication was WINGX [8].
Table 2 gives the atomic coordinates and equivalent thermal parameters of the nonhydrogen
atoms. Tables 3 and 4 give the list of bond lengths and bond angles, respectively.
The ORTEP of the molecule with thermal ellipsoids drawn at 50% probability is shown
in Fig. 2. The crystal structure is devoid of any classical hydrogen bonding, and molecules
. . .
are linked by weak intermolecular C H O interactions. In the 4-vinylbenzyloxy group,
the three H atoms and one C atom are disordered over two sets of sites, with site occupancy
factors of 0.75 and 0.25. The title compound has two 5-membered rings, both of them
are not on the same plane, and a chair conformation is adopted by the two fused five-
membered rings. The angle is 12.1(1)o between the plane of the C(15)–C(14)–C(11) and
the C(14)–C(11)–C(10) plane. The torsion angle of C(1)-N(1)-C(3)-C(2) is 28.9(6)o. The
Scheme 1. Synthesis of the title compound 1.

304
C. Zhang et al.
C(1)-N(1)-C(6) and O(3)-C(7)-C(8) bond angles are 118.7(5)o and 112.3(6)o, respectively.
The Packing diagram of (3) is given in Fig. 3.
Conclusion
The title compound, (6R,7aS)-1,1-Diphenyl-6-(4-vinylbenzyloxy)tetrahydropyrrolo [1,2-
1
c]oxazol-3(1H)-one, was synthesized and characterized by H, 13C NMR, and HRMS
spectroscopy. We summarized the results from X-ray diffraction measurements for com-
pound 1 single crystal. X-ray analysis revealed that the molecules are linked by weak
. . .
intermolecular C H O interactions. The three H atoms and one C atom are disordered
over two sets of sites.
Supplementary Information
CCDC 1026620 contains the supplementary crystallographic data for this article. These
data can be obtained free of charge via www.ccdc.cam.ac.uk/conts/retrieving.html, or from
The Cambridge Crystallographic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK.
Fax:+44(0)1223-336033. E-mail: deposit@ccdc.cam.ac.uk.
References
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