Russian Journal of Applied Chemistry, Vol. 74, No. 11, 2001, pp. 1888 1891. Translated from Zhurnal Prikladnoi Khimii, Vol. 74, No. 11,
2001, pp. 1829 1832.
Original Russian Text Copyright
2001 by Vyglazov, Chuiko, Izotova, Vintarskaya, Yudenko.
ORGANIC SYNTHESIS
AND INDUSTRIAL ORGANIC CHEMISTRY
Synthesis and Perfume Characteristics of Acetals
Containing an Aromatic Ring
O. G. Vyglazov, V. A. Chuiko, L. V. Izotova, Zh. V. Vintarskaya, and R. Ya. Yudenko
Institute of Physical Organic Chemistry, National Academy of Sciences of Belarus, Minsk, Belarus
Tereza-Inter Limited Liability Company, Moscow, Russia
Received March 15, 2001
Abstract Aromatic acetals were prepared by condensation of 2-methyl-3-(4-R-phenyl)propanals (R = Me,
i-Pr, i-Bu) with ethanol, methanol, ethylene glycol, 1,2-propanediol, methyl Cellosolve, and Cellosolve. The
perfume characteristics of the acetals were studied.
Thanks to active development of synthetic organic
chemistry, the set of available synthetic perfumes is
CHO
.
rapidly extended, with new classes of compounds
being involved. The use of new synthetic perfumes is
characterized by two features: (1) as a rule, substances
with interesting scent are discovered empirically;
(2) the perfume characteristics are studied for as many
structurally related compounds as possible, with the
aim to apply the developed processes to synthesis of
a wide set of perfumes.
III
Acetals are widely used are synthetic perfumes.
This mostly concernes diethyl, dimethyl, and ethylene
acetals, although derivatives of some other alcohols
(geraniol, isoamyl alcohol, 2-phenylethanol) are also
used [5]. To systematically study the structure scent
relationship in the series of acetals derived from I III,
we prepared the acetals with methanol, ethanol, ethyl-
ene glycol, 1,2-propanediol, and also with methyl
Cellosolve and Cellosolve (the two latter compounds
were not used previously for these purposes).
Such an approach inevitably sets a task of revealing
the structure scent relationship for perfumes, with the
aim to make a search for new perfumes purposeful.
At the same time, to find such a relationship, it is
necessary to prepare as many structural analogs as
possible.
The reaction is usually performed in the presence
of an acid catalyst; from the viewpoint of process
simplicity, it is convenient to use cation-exchange
resins, e.g., granulated KU-2 cation exchanger. The
reaction was performed in benzene in the presence of
FIBAN K-1 fibrous sulfonic cation exchanger as cata-
lyst. This resin was prepared by radiation-induced
grafting ot styrene (98%) 1,4-divinylbenzene (2%)
copolymer to a polypropylene thread, followed by
sulfonation with sulfuric acid.
Such studies were performed previously [1] but
became more active in the past years. For example,
the structure scent relationship was studied for the
series of 7-oxanorbornanes [2], monoterpene lactones
[3], and bicyclo[2.2.n]oximes [4].
In this work, starting from aldehydes in which the
carbonyl group is located in a side chain of an aromat-
ic ring, we prepared aromatic acetals and studied their
perfume characteristics. The initial compounds were
the aldehydes widely used in perfumery: jasmorange
[2-methyl-3-(4-methylphenyl)propanal, I], cyclamen-
aldehyde [2-methyl-3-(4-isopropylphenyl)propanal,
II], and lilial [2-methyl-3-(4-tert-butylphenyl)propan-
al, III]:
With this catalyst, owing to its developed surface
[6], the reaction time was reduced by a factor of 1.5 2
as compared to KU-2. Furthermore, the fibrous ion
exchanger did not noticeably lose its activity in re-
peated use, as demonstrated by the example of the
reaction of aldehydes I III with Cellosolve (Table 1).
CHO
CHO
The reaction progress was monitored by GLC. The
structure of the acetals was confirmed spectroscopi-
cally. In the H NMR spectra, a characteristic doublet
I
II
1
1070-4272/01/7411-1888$25.00 2001 MAIK Nauka/Interperiodica