1256
Z. Urbanczyk-Lipkowska et al. / Tetrahedron: Asymmetry 18 (2007) 1254–1256
interactions. The absolute configuration of the a-amino-e-
caprolactam molecule determined by comparison of the
known specific rotation of the free guest is in agreement
with the X-ray data.
AD-H (Daicel Chemical Industries, Ltd); eluent, hexane/
EtOH = 80/20; flow rate, 0.5 ml/min; detection, UV
220 nm; retention time, 17 min (S-enantiomer) and
15 min (R-enantiomer).
3.4. X-ray diffraction
3. Experimental
A suitable crystal was mounted on a glass fiber. Data col-
lection was performed at 295 K on a Nonius BV MACH
diffractometer with graphite monochromated CuKa
Melting points were measured by Stanford Research Sys-
tems MPA-100. H NMR spectra were obtained with a
1
JEOL EX-270. IR spectra were recorded on a JASCO
FT/IR 4100 spectrometer. Optical rotations were measured
on an ATAGO AP-100 polarimeter and enantiomeric
excesses were determined by HPLC on Chiralpak AD-H
(Daicel).
˚
(k = 1.54178 A). The structure was solved with direct
methods using the SHELXS975 and refined with SHELXL976
software. Refinement was performed anisotropically for
all non-hydrogen atoms using the full-matrix least-squares
method. In general, hydrogen atoms were assigned to ide-
alized positions and were allowed to ride with thermal
parameters fixed at 1.2Ueq of the parent atom. Hydroxyl
group H-atoms were localized from Dq maps and refined.
The residual electron densities were of no chemical signifi-
cance. Crystal data: (1:1) Inclusion complex of (R,R)-(À)-1
and (S)-(À)-5: C37H42N2O5 Fw = 599.77; monoclinic space
3.1. Resolution of 3-aminopiperidin-2-one 4 by inclusion
complexation with (R,R)-(À)-2
When a solution of (R,R)-(À)-2 (0.66 g, 1.32 mmol) and
( )-4 (0.30 g, 2.64 mmol) in toluene (10 ml) was kept at
room temperature for several days, colorless prisms of
the 1:1 inclusion complex of (R,R)-(À)-2 with (S)-(À)-4
(0.37 g, mp 160–166 °C) were formed. The crystals were
˚
group P21, a = 9.719(2), b = 9.763(2), c = 17.583(4) A,
3
˚
b = 100.66(3)°, V = 1639.6(6) A , Z = 2, Dc = 1.205,
1
F(000) = 1272. 3487 reflections collected in the h-range
5.61–74.05°, 3385 unique [R(int) = 0.04]. Final R index
R1 = 0.0490 [1891 reflections with I > 2r(I)], and for all
data wR = 0.1540, S = 1.053; Flack parameter À0.1(4).
analyzed by H NMR spectra to determine the host–guest
ratios. From the 1:1 inclusion complex, (S)-(À)-4 (0.04 g,
27% yield, >99% ee) was obtained by silica-gel column
chromatographic separation. The enantiomeric excess was
determined by HPLC analysis with Chiralpak AD-H (Dai-
cel Chemical Industries, Ltd); eluent, hexane/EtOH = 80/
20; flow rate, 0.5 ml/min; detection, UV 220 nm; retention
time, 38 min (S-enantiomer) and 35 min (R-enantiomer).
CCDC-643247, contains the supplementary crystallo-
graphic data for this paper. These data can be obtained free
ing.html’ [or from the Cambridge Crystallographic Data
Centre, 12, Union Road, Cambridge CB2 1EZ, UK;
e-mail: deposit@ccdc.cam.sc.uk].
3.2. Resolution of a-amino-e-caprolactam 5 by inclusion
complexation with (R,R)-(À)-1
When a solution of (R,R)-(À)-1 (1.21 g, 2.6 mmol) and ( )-
5 (0.66 g, 5.2 mmol) in toluene (20 ml) was kept at room
temperature for several days, colorless prisms of the 1:1
inclusion complex of (R,R)-(À)-1 with (S)-(À)-5 (0.84 g,
mp 162–167 °C) were formed. The crystals were analyzed
by 1H NMR spectra to determine the host–guest ratio.
From the 1:1 inclusion complex, (S)-(À)-5 (0.10 g, 30%
yield, >99% ee) was obtained by silica-gel column chro-
matographic separation. The enantiomeric excess was
determined by HPLC analysis with Chiralpak AD-H (Dai-
cel Chemical Industries, Ltd); eluent, hexane/EtOH = 80/
20; flow rate, 0.5 ml/min; detection, UV 220 nm; retention
time, 31 min (S-enantiomer) and 33 min (R-enantiomer).
Acknowledgments
Z.U.-L. acknowledges the financial support from JSPS
Program and grant from the Ministry of Science and Edu-
cation No. 3T09B 115 28. K.T. acknowledges the financial
support from ‘High-Tech Research Center’ Project for
Private Universities: mating fund subsidy from MEXT
(Ministry of Education, Culture, Sports, Science and
Technology), 2005–2009.
References
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London, 1992; Vol. 2, p 149.
2. Recent example: Tanaka, K.; Kuchiki, D.; Caira, M. R.
Tetrahedron: Asymmetry 2006, 17, 1678–1683.
3.3. Resolution of 6-methyl-2-piperidone 7 by inclusion
complexation with (R,R)-(À)-1
3. Toda, F.; Tohi, Y. J. Chem. Soc., Chem. Commun. 1993, 1238.
4. (a) Sakai, K.; Sakurai, R.; Hirayama, N. Tetrahedron:
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5. Sheldrick, G. M. SHELS-97, Program for Crystal Structure
Solution; Univerity of Go¨ttingen: Germany, 1997.
6. Sheldrick, G. M. SHELXL97, Program for Crystal Structure
Refinement; University of Go¨ttingen: Germany, 1997.
When a solution of (R,R)-(À)-1 (0.62 g, 1.33 mmol) and
( )-7 (0.30 g, 2.65 mmol) in toluene (10 ml) was kept at
room temperature for several days, colorless prisms of
the inclusion complex of (R,R)-(À)-1 and (R)-(À)-7
(0.23 g, mp 144–146 °C) were obtained. Upon heating of
the inclusion complex at 210 °C in vacuo, (R)-(À)-7 was
obtained in 69% ee (0.016 g, 28% yield). The enantiomeric
excess was determined by HPLC analysis with Chiralpak