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I. Panov et al.
LETTER
(
4) Kaldor, S. W.; Kalish, V. J.; Davies, J. F. II.; Shetty, B. V.;
Fritz, J. E.; Appelt, K.; Burgess, J. A.; Campanale, K. M.;
Chirgadze, N. Y.; Clawson, D. K.; Dressman, B. A.; Hatch,
S. D.; Khalil, D. A.; Kosa, M. B.; Lubbehusen, P. P.;
Muesing, M. A.; Patick, A. K.; Reich, S. H.; Su, K. S.;
Tatlock, J. H. J. Med. Chem. 1997, 40, 3979.
(17) Panov, I.; Drabina, P.; Padělková, Z.; Šimůnek, P.; Sedlák,
M. J. Org. Chem. 2011, 76, 4787.
(18) Drabina, P.; Karel, S.; Panov, I.; Sedlák, M. Tetrahedron:
Asymmetry 2013, 24, 334.
(19) One of the ligands L1 or L2 (0.055 mmol) and Cu(OAc)2
(9.1 mg, 0.05 mmol) were stirred for 1 h in a mixture of
(
5) Roberts, N. A.; Martin, J. A.; Kinchington, D.; Broadhurst,
A. V.; Craig, J. C.; Duncan, I. B.; Galphin, S. A.; Handa, B.
K.; Krohn, A.; Lambert, R. W.; Merrett, J. H.; Mills, J. S.;
Parkes, K. E. B.; Redshaw, S.; Ritchie, A. J.; Taylor, D. L.;
Thomas, G. J.; Machin, P. J. Science 1990, 248, 358.
6) Honda, Y.; Katayama, S.; Kojima, M.; Suzuki, T.;
Kishibata, N.; Izawa, K. Org. Biomol. Chem. 2004, 2, 2061.
7) Corey, E. J.; Zhang, F.-U. Angew. Chem. Int. Ed. 1999, 38,
EtOH (1.5 mL) and MeNO (0.54 mL, 10 mmol) at r.t. to
2
generate the catalyst. The solution was cooled to 18 °C, and
then the aldehyde (1 mmol) was added. The mixture was
stirred for the 96 h, the solvents were removed under reduced
pressure, and the product was purified by short flash
chromatography using EtOAc as an eluent.
(
(
(
(
(20) The diastereomeric ratio of 4c/5c was determined by HPLC
with a Chiralcel AD-H column [hexane–isopropyl alcohol
(90:10), 0.8 mL/min, 254 nm]: t (5c) = 12.1 min; t (4c) =
1
931.
R
R
8) Gadakh, S. K.; Reddy, R. S.; Sudalai, A. Tetrahedron:
Asymmetry 2012, 23, 898.
9) Kim, B. M.; Bae, S. J.; So, S. M.; Yoo, H. T.; Chang, S. K.;
Lee, J. H.; Kang, J. S. Org. Lett. 2001, 3, 2349.
23.1 min.
1
(21) Compound 5c: yield 291 mg (94%); mp 168–170 °C. H
NMR (400 MHz, DMSO-d , 75 °C): δ = 7.28–7.15 (m, 5 H,
6
ArH), 6.47 (br s, 1 H, NH), 5.51 (d, J = 6.9 Hz, 1 H, OH),
(
(
(
(
(
(
(
10) Nogami, H.; Kanai, M.; Shibasaki, M. Chem. Pharm. Bull.
003, 51, 702.
11) Arai, T.; Taneda, Y.; Endo, Y. Chem. Commun. 2010, 46,
936.
12) Sasai, H.; Kim, W.-S.; Suzuki, T.; Shibasaki, M.
Tetrahedron Lett. 1994, 35, 6123.
4.67 (dd, J = 12.5, 3.0 Hz, 1 H, CH ), 4.39 (dd, J = 12.5, 9.2
2
2
Hz, 1 H, CH ), 4.19–4.10 (m, 1 H, CHOH), 3.69–3.61 (m, 1
2
H, CHNH), 3.02 (dd, J = 13.5, 3.8 Hz, 1 H, CH ), 2.62 (dd, J
2
1
3
7
= 13.5, 10.1 Hz, 1 H, CH ), 1.28 (s, 9 H, t-Bu). C NMR
2
(100 Mz, DMSO-d ): δ = 155.4, 139.0, 129.2, 128.1, 125.9,
6
80.0, 77.9, 71.2, 54.7, 36.0, 28.2.
(22) Compound 4c: yield 280 mg (89%); mp 133–134 °C. H
1
13) Palomo, C.; Oiarbide, M.; Laso, A. Eur. J. Org. Chem. 2007,
2
561.
NMR (400 MHz, DMSO-d , 75 °C): δ = 7.28–7.17 (m, 5 H,
6
14) Reddy, B. V. S.; Reddy, S. M.; Manisha, S.; Madan, C.
Tetrahedron: Asymmetry 2011, 22, 530.
15) Xu, K.; Lai, G.; Zha, Z.; Pan, S.; Chen, H.; Wang, Z. Chem.
Eur. J. 2012, 18, 12357.
16) Sedlák, M.; Drabina, P.; Keder, R.; Hanusek, J.; Císařová, I.;
Růžička, A. J. Organomet. Chem. 2006, 691, 2623.
ArH), 6.31 (br s, 1 H, NH), 5.42 (d, J = 6.6 Hz, 1 H, OH),
4.67 (dd, J = 12.5, 2.0 Hz, 1 H, CH ), 4.37–4.32 (m, 1 H,
2
CH ), 4.23–4.19 (m, 1 H, CHOH), 3.79–3.77 (m, 1 H, CHNH),
2
2.88 (dd, J = 13.7, 5.1 Hz, 1 H, CH ), 2.66 (dd, J = 13.6, 9.4
2
1
3
Hz, 1 H, CH ), 1.31 (s, 9 H, t-Bu). C NMR (100 Mz,
2
DMSO-d ): δ = 155.4, 139.0, 129.2, 128.2, 126.1, 79.5, 78.0,
6
69.8, 54.4, 35.7, 28.2.
Synlett 2013, 24, 1280–1282
© Georg Thieme Verlag Stuttgart · New York