ISSN 1070-4272, Russian Journal of Applied Chemistry, 2006, Vol. 79, No. 12, pp. 1982 1985.
Pleiades Publishing, Inc., 2006.
Original Russian Text
pp. 2007 2010.
E.A. Dikusar, N.A. Zhukovskaya, O.G. Vyglazov, 2006, published in Zhurnal Prikladnoi Khimii, 2006, Vol. 79, No. 12,
ORGANIC SYNTHESIS
AND INDUSTRIAL ORGANIC CHEMISTRY
Synthesis of Esters of D, L-, D(+)-, and L( )-Camphor Oximes:
Structure Odor Correlation
E. A. Dikusar, N. A. Zhukovskaya, and O. G. Vyglazov
Institute of Physical Organic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
Tereza Inter Limited Liability Company, Moscow, Russia
Received April 13, 2006
Abstract Esters of D, L-, D(+)-, and L( )-camphor oximes were synthesized, and the correlation between
their structure and odor was examined.
DOI: 10.1134/S1070427206120147
Examination of the correlation between the tints
and scents of fragrance compounds and odorants, on
the one hand, and structures of fragments of natural
compounds used in the synthesis of these substances,
on the other hand, is a topical problem of fragrance
chemistry [1 3].
Camphor oxime esters VIIa VIIv, VIIIa VIIId,
and IXa IXd were prepared by the reactions of IV VI
with appropriate alkane- or arenecarboxylic acid anhy-
drides or chlorides in absolute hexane or benzene. The
reactions with carboxylic acid chlorides were per-
formed in the presence of pyridine. The reactant ratio
was stoichiometric (1 : 1 or 1 : 1 : 1). By these reac-
tions, the starting oximes IV VI were converted to
the corresponding esters VIIa VIIw, VIIIa VIIId,
and IXa IXd in yields of 88 92%.
In this study we developed a convenient procedure
for preparing esters of D, L-, D(+)-, and L( )-camphor
oximes and examined the correlation between their
odor and structure:
Camphor oxime esters VIIa VIIw, VIIIa VIIId,
and IXa IXd are colorless liquids or crystalline sub-
stances (crystallizing from hexane) (Table 1). The es-
ters do not require additional purification, contain no
admixtures of the starting compounds, benzene, and
pyridine, and are suitable for direct use in fragrance
and food industry [4]. The purity of the compounds
NH2OH
N
O
OH
I, II, III
IV, V, VI
1
was 97 98% according to the H NMR spectra.
The structure and properties of camphor oxime
esters VIIa VIIv, VIIIa VIIId, and IXa IXd were
confirmed by elemental analysis, cryoscopic deter-
mination of the molecular weight (Table 1), and H
NMR, IR, and UV spectroscopy.
N
OCR
O
1
VIIa VIIv, VIIIa VIIId, IXa IXd
I, IV, VII: D, L-camphor and its oxime and esters, re-
spectively; II, V, VIII: D(+)-camphor and its oxime
and esters, respectively; III, VI, IX: L( )-camphor and
its oxime and esters, respectively; VII, VIII, IX: R =
Me (a), Et (b), Pr (c), CHMe2 (d), Bu (e), CH2CHMe2
(f), (CH2)4Me (g), (CH2)5Me (h), (CH2)6Me (i),
(CH2)7Me (j), (CH2)8Me (k), (CH2)11Me (l), (CH2)16Me
(m), CHBrCCl=CCl2 (n), (CH2)2C(O)OMe (o), C6H11-
cyclo (p), C6H5 (q), C6H4Cl-2 (r), C6H3Cl2-2,4 (s),
CH2OC6H3Cl2-2,4 (t), C6H4NO2-3 (u), C6H4NO2-4
(v), C6H3(NO2)2-3,5 (w).
The IR spectra of VIIa VIIv, VIIIa VIIId, and
IXa IXd contain the following characteristic absorp-
1
tion bands ( , cm ): 3020 2800 (CHAlk), 1780 1750
(C=O), 1670 1660 (C=N), 1100 1220 (C O), and
910 1000 (N O).
The UV spectra of VIIa VIIv, VIIIa VIIId, and
IXa IXd show an absorption peak at 208 nm ( 4000)
assigned to the C=N O fragment.
In the 1H NMR spectra of VIIa VIIv, VIIIa VIIId,
and IXa IXd, the methyl groups of the bicyclic core
1982