8658
V. Capriati et al. / Tetrahedron Letters 48 (2007) 8655–8658
was evaporated and the crude mixture was purified by
flash chromatography (CH2Cl2/MeOH 9:1).
6. Kamata, K.; Agata, I.; Meyers, A. I. J. Org. Chem. 1998,
63, 3113–3116.
also a potential as chiral auxiliaries in asymmetric
synthesis.3
7. Abbotto, A.; Bradamante, S.; Florio, S.; Capriati, V. J.
Org. Chem. 1997, 62, 8937–8940.
Acknowledgements
8. Typical procedure for the preparation of equilibrating
mixtures of spirocyclic compounds 10 and hydroxylamines
11: To a pre-cooled (ꢀ78 ꢁC, dry ice/acetone bath)
solution of alkyloxazoline 9 (1.2 mmol) in 10 mL of
THF under N2 was added s-BuLi (solution in cyclohexane
1.4 M, 1.2 mmol). The resulting orange mixture was
stirred for 20 min at this temperature before adding slowly
a solution of the nitrone 2a (THF, 5 mL, 1.0 mmol). Then,
the reaction mixture was warmed up to room temperature,
quenched with satd aq NH4Cl, poured into 20.0 mL of
saturated brine, extracted with Et2O (3 · 10 mL), dried
(Na2SO4) and the solvent evaporated under reduced
pressure. The crude mixture was flash-chromatographed
(silica gel; petroleum ether/AcOEt = 7–8:3–2) to give a
mixture of N-cumyl-1,6-dioxa-4,7-diazaspiro[4,4]nonanes
10 and corresponding N-cumyl-hydroxylamine 11.
9. General procedure for the preparation of 3-aminoalkana-
mides 12: To a solution of equilibrating mixture of 10 and
11 (0.5 mmol) in MeOH (5.0 mL) Pd/C (10% mol) was
added and the resulting mixture was hydrogenated in a
This work was carried out under the framework of the
National Project ‘Stereoselezione in Sintesi Organica.
Metodologie ed Applicazioni’ and financially supported
by MIUR and the University of Bari.
Supplementary data
Supplementary data associated with this article can be
References and notes
1. Capriati, V.; Degennaro, L.; Florio, S.; Luisi, R. Tetra-
2. Neuhaus, D.; Williamson, M. In The Nuclear Overhauser
Effect in Structural and Conformational Analysis; VCH:
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3. (a) Beaulieu, F.; Arora, J.; Veith, V.; Taylor, N.; Chapell,
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8728; (b) Chu, K. S.; Konopelski, J. P. Tetrahedron 1993,
49, 9183–9190.
‘Buchi Mini Clave’ apparatus at 10 bar overnight. Then,
¨
the solution was filtered on a Celite pad and the solvent
evaporated in vacuo affording the 3-aminoalkanamides
(12) that did not need further purification.
10. General procedure for the preparation of b-phenylaminoal-
kanamides 13: To an equilibrating mixture of the spiro-
cyclic compound 10 and hydroxylamine 11 (0.3 mmol) in
dioxane/H2O (4:1, 5 mL) CF3COOH (20 lL) was added
and the resulting mixture stirred for 24 h at rt. After this
time, the reaction mixture was poured into water,
extracted with AcOEt (3 · 10 mL), dried on Na2SO4,
filtered and the volatiles were removed under reduced
pressure. Column chromatography (AcOEt/petroleum
ether, 1:4) furnished the phenylaminoalkanamides 13.
11. (a) Hoobler, M. A.; Bergbreiter, D. A.; Newcomb, M. J.
Am. Chem. Soc. 1978, 100, 8182; (b) Meyers, A. I.; Snyder,
E. S.; Ackerman, J. J. H. J. Am. Chem. Soc. 1978, 100,
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´
´
4. (a) Hajji, C.; Testa, M. L.; Zaballos-Garcıa, E.; Zaragoza,
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´
R. J.; Server-Carrio, J.; Sepulveda-Arques, J. Tetrahedron
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1081–1088; (c) Melon, D.; Gravier-Pelletier, C.; Le
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5. General procedure for the preparation of hexahydro-4-
pyrimidinones 7a,b: A solution of 5a (0.1 mmol, 31 mg) in
MeOH (5.0 mL) and paraformaldehyde (10 mg) was
heated in a sealed reactor at 100 ꢁC for 8 h. The solvent