Comments on 'Unusual oxidative rearrangement of 1,5-diazadecalin'

Article abstract of DOI:10.1016/j.tetlet.2004.01.062

Oxidation of cis or trans 1,5-diazadecalin with (PhIO)_n yields 2-pyrrolidinone and not 1,6-diaza-2,7-cyclodecadione, as reported. This is shown by a comparison of the NMR data of the reaction product with those of 2-pyrrolidinone and 1,6-diaza-2,7-cyclodecadione.

Full text of DOI:10.1016/j.tetlet.2004.01.062

Tetrahedron
Letters
Tetrahedron Letters 45 (2004) 2051–2052
Comments on ÔUnusual oxidative rearrangement
of 1,5-diazadecalinÕ
Tammo Winkler*
Syngenta Crop Protection AG, CH 4002 Basel, Switzerland
Received 9 January 2004; revised 14 January 2004; accepted 16 January 2004
n
Abstract—Oxidation of cis or trans 1,5-diazadecalin with (PhIO) yields 2-pyrrolidinone and not 1,6-diaza-2,7-cyclodecadione, as
reported. This is shown by a comparison ofthe NMR data ofthe reaction product with those of2-pyrrolidinone and 1,6-diaza-2,7-
cyclodecadione.
Ó 2004 Elsevier Ltd. All rights reserved.
1
1
It was recently reported in this journal that oxidation of
cis or trans 1,5-diazadecalin (1) with (PhIO) yields the
ring expanded bislactam 1,6-diaza-2,7-cyclodecadione
2) (Scheme 1). The reaction product was described as
the H NMR spectrum of 2 in CDCl shows six separate
3
n
signals for the axial and equatorial protons of the three
nonequivalent CH groups due to the stable centro-
2
symmetrical crown conformation of the macrocyclic
ring. A detailed analysis ofthis spectrum has been
published in 1982 in a study ofthe solution con of rma-
(
an oil and its NMR data were given. 1,6-Diaza-2,7-
cyclodecadione, however, is a high-melting solid, whose
X-ray structure analysis has been published. Further-
more, the H and C NMR data given for the reaction
product are those of2-pyrrolidinone 3, as can easily be
seen by a comparison with literature data of2-pyrro-
2
4
tion of 2.
1
13
1
The formation of 2-pyrrolidinone can be explained by
1
the decay ofthe postulated intermediate bisimine 4 to
the monomeric 1-pyrroline (5) or its hydrate, which is in
3
4
lidinone and of 2 (see Table 1). At room temperature,
O
H
N
(
PhIO)n
HN
(PhIO)n
X
NH
O
N
H
N
H
O
3
2
1
(
PhIO)n
(
PhIO)n
2
H
N
N
-
-
PhI
H O
2
N
N
N
4
5
I
Ph
OH
Scheme 1.
Keywords: Diazadecalins; Macrocyclic bislactams; NMR; Conformational analysis.
*
Tel.: +41-613-235047; fax: +41-613-233704; e-mail: tammo.winkler@syngenta.com
0
040-4039/$ - see front matter Ó 2004 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tetlet.2004.01.062

2052
T.Winkler / Tetrahedron Letters 45 (2004) 2051–2052
1
3
1
Table 1. C and H NMR chemical shifts of 2 and 3 in CDCl
3
References and notes
C(2)
C(3)
C(4)
C(5)
1
2
. Li, X.; Xu, Z.; DiMauro, E. F.; Kozlowski, M. C.
Tetrahedron Lett. 2002, 43, 3747–3750.
a
1
3
2
3
3
175.4
179.8
179.59
35.7
30.5
30.28
26.6
21.2
20.75
39.4
42.7
. Tereshko, V.; Monserrat, J. M.; P ꢀe rez-Folch, J.; Aymam ꢀı ,
J.; Fita, I.; Subirana, J. A. Acta Crystallogr., Sect. B 1994,
B50, 243–251.
42.44
H-3
2.01 t,
H-4
2.17 q,
H-5
b
13
2
4.10 q,
2.91 d
3.36 t
3.40 t
3. Pouchert, C. J.; Behnke, J. In The Aldrich Library of
C
1
2.32 d
1.80 d
2.08 quintet
2.12 quintet
and H FT NMR Spectra, 1st ed.; Aldrich Chemical
Company: Milwaukee, 1993; Vol. 1, p 1285, spectra B.
4. Winkler, T.; Leutert, T. Helv.Chim.Acta 1982, 65, 1760–
1
3
3
3
2.25 t
2.29 t
1
. Ochiai, M.; Inenaga, M.; Nagao, Y.; Moriarty, R. M.;
763.
a
13
4
This work; cf. C NMR chemical shifts in DMSO-d
6
6
or EtOH-d .
5
b
The chemical shift of the axial protons is listed first. At 25 °C, a slight
exchange broadening is observed: Therefore only the multiplicities
caused by the large geminal and trans diaxial vicinal coupling con-
Vaid, R. K.; Duncan, M. P. Tetrahedron Lett. 1988, 29,
6
917–6920.
4
stants are given (cf. the analysis ofthe spectrum at 0 °C).
5
turn oxidized to 2-pyrrolidinone as shown by Ochiai
et al. (see Scheme 1).