Oxidation of mandelic acid derivatives catalysed by Bi(0)/O2 systems: Mechanistic considerations

Article abstract of DOI:10.1016/S0040-4020(03)00083-8

Mandelic acid and some aryl substituted derivatives were oxidised under molecular oxygen and a catalytic amount of Bi(0). The corresponding aldehydes and/or the carboxylic acids were obtained selectively depending on the nature of the substituent. Aldehydes and α-keto acids were oxidised under the same Bi(0)/O₂ system and α-keto acids were proposed as intermediates in the formation of benzoic acid derivatives.

Full text of DOI:10.1016/S0040-4020(03)00083-8

Tetrahedron 59 (2003) 1823–1830
Oxidation of mandelic acid derivatives catalysed by Bi(0)/O2
systems: mechanistic considerations
Isabelle Faviera and Elisabet Dun˜achb
,
*
a
ˆ
`
´
Laboratoire Aromes Syntheses et Interactions, Universite de Nice-Sophia Antipolis, Parc Valrose, 06108 Nice Cedex 2, France
´
Laboratoire de Chimie Bioorganique, UMR CNRS 6001, Universite de Nice-Sophia Antipolis, 06108 Nice Cedex 2, France
b
Received 4 October 2002; revised 12 December 2002; accepted 6 January 2003
Abstract—Mandelic acid and some aryl substituted derivatives were oxidised under molecular oxygen and a catalytic amount of Bi(0).
The corresponding aldehydes and/or the carboxylic acids were obtained selectively depending on the nature of the substituent. Aldehydes and
a-keto acids were oxidised under the same Bi(0)/O2 system and a-keto acids were proposed as intermediates in the formation of benzoic acid
derivatives. q 2003 Elsevier Science Ltd. All rights reserved.
1. Introduction
stoichiometric oxidation systems have been reported for this
decarboxylative oxidation of mandelic acids to the corre-
sponding aldehydes.10 Among the catalytic reactions, Fe(II)
and Cu(II) systems with H2O2 or S2O282 as the oxidants,11,12
The most general utilisation of mandelic acid and its
derivatives in industrial applications concerns their oxi-
dation, which allows the access to aromatic aldehydes.1 In
particular, hydroxy- and alkoxy-substituted aldehydes
constitute important products, used in the field of flavours
and perfumes.2,3 Mandelic acid derivatives are also used as
intermediates in the field of agrochemicals, pharmaceuticals
and in cosmetology.4–6 Thus, piperonal (heliotropin) or
vanillin are obtained from the oxidation of 3,4-methylene-
dioxymandelic acid7 or 4-hydroxy-3-methoxymandelic acid
(or VMA), respectively, (Scheme 1).1,8,9
Cr(V)13 or KMnO4 with HClO4, or Cu(II)/O2 systems
14
have been described.15
The oxidation of mandelic acids can also afford the
corresponding benzoic acids or the arylglyoxylic acids.
Thus, phenylglyoxylic acid has been obtained from the O2
oxidation of mandelic acid in the presence of Cu(II),16 Pd/C,
or Pt/C catalytic systems.17 The oxidation to benzoic acid
derivatives has been reported with Ce(IV) or Mn(II) in the
presence of bromide ions, with Ru(VI)/Fe(III) or with
Co(III)/O2 systems.18–20
The oxidation of mandelic acids can afford different
oxidation products: the corresponding aldehyde, the car-
boxylic acid and the a-keto acid. A large variety of
Despite these numerous studies, there has been no
systematic study undertaken concerning the oxidation of
mandelic acids. We present here systematic mechanistic
considerations of this reaction with a bismuth-based
catalytic system.
We have shown that some Bi(III) complexes such as Bi(III)-
mandelate, in the presence of molecular oxygen, presented
an interesting catalytic activity towards the oxidation
and the oxidative C–C bond cleavage of epoxides and
a-ketols.21–23 More recently, metallic bismuth powder has
also been reported as an efficient catalyst for the oxidation
of these families of compounds, including the oxidation of
a-hydroxy acids.24
Scheme 1. Oxidative decarboxylation of VMA.
The use of other bismuth derivatives in the oxidation of
mandelic acids has been limited to the stoichiometric
utilisation of sodium bismuthate25 and of bismuth nitrate26
leading to benzaldehydes and benzoic acids, respectively.
Keywords: mandelic acid; oxidation; bismuth; molecular oxygen;
substituent effects.
*
Corresponding author. Tel.: þ33-4-92-07-61-42; fax: þ33-4-92-07-61-
51; e-mail: dunach@unice.fr
0040–4020/03/$ - see front matter q 2003 Elsevier Science Ltd. All rights reserved.
doi:10.1016/S0040-4020(03)00083-8

1824
I. Favier, E. Dun˜ach / Tetrahedron 59 (2003) 1823–1830
Scheme 2. Pathways for the oxidation of mandelic acid derivatives catalysed by Bi(0)/O2 system.
On the other hand, bismuth (III) derivatives have been
described in the last years as possessing interesting Lewis
acid character, able to catalyse, for example, the deprotec-
tion of acetals27 and S,S-acetals,28 the isomerisation of
epoxides,29 the sulfonylation reaction,30 the acetylation and
benzoylation of alcohols31 the Mukaiyama aldol reaction,32
the Diels–Alder reaction,33,34 as well as other organic
transformations.35
reaction (Eq. (1)).
ð1Þ
In the present study, we summarise our results on the bi-
catalysed oxidation of differently substituted mandelic
acids, benzaldehydes and phenylglyoxylic acids, in order
to get a better understanding of the factors that govern the
reaction chemoselectivity, and in order to propose plausible
mechanistic pathways and intermediates for the oxidation of
the various substrates examined.
As shown in Table 1, whereas the oxidation of unsubstituted
mandelic acid, 1a led to the selective formation of benzoic
acid, 4a, the oxidation of 4-hydroxy-3-methoxymandelic
acid, 1d, afforded the corresponding aldehyde, 2d, in high
selectivity. In a recent study,36 we could distinguish
between two types of substitution on the aryl ring able to
strongly influence the reactivity and the selectivity of the
oxidation of mandelic acid derivatives. Thus, the presence
of electron-withdrawing substituents allowed the selective
formation of benzoic acids, 4. In contrast, mandelic acid
derivatives possessing an hydroxy substituent at the 2- or
4-positions of the aryl group tended to favour the formation
of the corresponding benzaldehydes, 2.
2. Results and discussion
The oxidation of mandelic acids (or one of its aryl
derivatives), 1, can afford benzaldehydes, 2, arylglyoxylic
acids, 3, and/or the benzoic acid derivatives, 4. As shown in
Scheme 2, the oxidative decarboxylation of 1 may directly
afford 2, which, in turn can be oxidised to 4 (path (a)). In an
alternative pathway (path (b)), the alcohol oxidation of 1
may lead to keto acid 3, which can be either decarboxylated
to 2 or undergo an oxidative decarboxylation to 4.
To complete this study, we examined the reactivity of four
model compounds, differently substituted in the aromatic
ring, under oxidative catalytic conditions, using the system
Bi(0) under molecular oxygen. The oxidations were carried
out in DMSO/AcOH as the reaction medium at 1258C, with
10 mol% of catalyst with respect to the substrate. Under
these conditions, the commercially available and non-toxic
Bi(0) powder could be dissolved and an homogeneous
yellow solution was obtained. A Bi(III)/Bi(0) redox couple
was operating as the catalytic system, able to activate O2 at
During the oxidation of differently substituted mandelic
acids in the presence of Bi(0)/O2 as the catalytic system,
we observed that the nature of the substituents on the aryl
ring was chemoselectively influencing the outcome of the
Table 1. Oxidation of mandelic acid derivatives catalysed by Bi(0)/O2 system
Substrate
R1
R2
Time
Conversion (%)
Yields (%) /conversion 2þ4
Selectivity 2/4
1a
1b
1c
1d
1e
H
H
H
H
OMe
H
24 h
6 h
24 h
40 min
6 h
54
77
97
97
81a
100
100
100
98
7:93
38:62
1:99
87:13
77:23
OMe
CF3
OH
OH
100
a
Phenylglyoxylic acid 3a was also obtained in 19% yield.

I. Favier, E. Dun˜ach / Tetrahedron 59 (2003) 1823–1830
1825
Table 2. Oxidation of mandelic acid, 1a, benzaldehyde, 2a and
phenylglyoxylic acid, 3a, catalysed by Bi(0)/O2 system for 24 h reaction
Substrate
Conversion (%)
Products formed
and selectivity
2a
3a
4a
1a
2a
3a
54
15
85
6
–
–
19
–
–
75
100
100
atmospheric pressure. Model compounds chosen were
mandelic acid, 1a, 4-methoxymandelic acid, 1b, 4-trifluoro-
methylmandelic acid, 1c, and 4-hydroxy-3-methoxyman-
delic acid, 1d. We examined as well, the oxidation of the
corresponding benzaldehydes, 2a–d, and arylglyoxylic
acids, 3a–c. The oxidation of 4-hydroxy mandelic acid 1e
was also examined, for comparison.
Figure 2. Oxidation of p-methoxymandelic acid, p-methoxybenzaldehyde
and p-methoxyphenyglyoxylic acid catalysed by Bi(0)/O2.
2.2. Oxidation of 4-methoxymandelic acid, 4-methoxy-
benzaldehyde and 4- methoxyphenylglyoxylic acid
2.1. Oxidation of mandelic acid, benzaldehyde and
phenylglyoxylic acid
The kinetics of the Bi(0)/O2 oxidation reactions of 4-methoxy-
mandelic acid, 1b, 4-methoxybenzaldehyde, 2b, and
4-methoxyphenylglyoxylic acid, 3b, are presented in Figure
2. Both 4-methoxymandelic acid and 4-methoxyphenyl-
glyoxylic acid reacted at similar rates, and faster than the
aldehyde, 2b. Conversions and selectivities in 4-methoxy-
benzoic acid, 4b, are presented in Table 3.
Under the standard reaction conditions, the oxidation of
mandelic acid, 1a, led, after 24 h to a 54% conversion.
Among the compounds formed, the major product was
benzoic acid, 4a, obtained with a selectivity of 75%.
Benzaldehyde, 2a and phenylglyoxylic acid, 3a were
obtained in 6 and 19% selectivity, respectively, (Table 2).
The oxidation of 1b led, after 6 h, to a 77% conversion into
a mixture of aldehyde 2b and carboxylic acid 4b with a
selectivity 2b:4b of 38:62. It is to be noted that 3b was not
isolated from the oxidation of 1b. The oxidation of 3b
afforded selectively 4b in 98%.
Both 2a and 3a being possible intermediates in the
formation of 4a, their oxidation was run under the same
conditions. Benzaldehyde was converted into benzoic acid
in only 15% after 24 h. In contrast, the oxidation of
phenylglyoxylic acid, 3a afforded, under the same con-
ditions, 85% conversion with exclusive formation of 4a.
The aldehyde 2b being only slowly oxidised to 4b, the
formation of 4b from 1b is essentially due to its oxidation
These results indicated that benzaldehyde 2a is not a
plausible intermediate in the oxidation of 1a to 4a (Scheme
2). However, the keto acid, 3a, constitutes an intermediate
compatible with the oxidation kinetics. The kinetic
evolution of the oxidation of a 1:1 mixture of 1a and 3a is
presented in Figure 1. The reaction was followed by NMR,
after treating aliquot samples from the reacting mixture.
Table 3. Oxidation of p-methoxymandelic acid, p-methoxybenzaldehyde
and p-methoxyphenyglyoxylic acid catalysed by Bi(0)/O2
Substrate
Time (h)
Conversion (%)
Products formed and
selectivity
2b
3b
4b
As shown in Figure 1, the keto acid 3a is oxidised at a higher
rate than 1a. This is in agreement with a mechanism
following path (b) in Scheme 2.
1b
2b
3b
6
24
24
77
32
80
38
–
2
–
–
–
62
100
98
Figure 1. Oxidation of a mixture of mandelic acid and phenylglyoxylic acid (1:1) catalysed by Bi(0)/O2.

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I. Favier, E. Dun˜ach / Tetrahedron 59 (2003) 1823–1830
Table 5. Oxidation of VMA and vanillin catalysed by Bi(0)/O2
Substrate
Time
Conversion (%)
Products formed
and selectivity
2d
3d
4d
1d
2d
20 min
40 min
24 h
69
97
100
25
99
87
61
–
–
–
–
–
1
13
31
68
24 h
and it does not constitute an intermediate in the oxidation of
1c to 4c. Thus, the oxidation of 4-trifluoromethylmandelic
acid, 1c follows almost exclusively path (b) in Scheme 2.
Figure 3. Oxidation of p-trifluoromethylmandelic acid, p-trifluoromethyl-
benzaldehyde and p-trifluoromethylphenylglyoxylic acid catalysed by
Bi(0)/O2.
2.4. Oxidation of 4-hydroxy-3-methoxymandelic acid
and 4-hydroxy-3-methoxybenzaldehyde
via the keto acid 3b, following path (b) in Scheme 2,
according to the data in Table 3.
The oxidation of 4-hydroxy-3-methoxymandelic acid or
vanillic mandelic acid, 1d, and of 4-hydroxy-3-methoxy-
benzaldehyde or vanillin, 2d, was carried out by the
Bi(0)/O2 system. In the case of the 4-hydroxy-3-methoxy
substituted derivatives, several attempts to prepare the keto
acid derivative, 3d, were unsuccessful.
In the oxidation of 1b, the aldehyde 2b, present with a
selectivity of 38%, is not issued from the keto acid
intermediate. The aldehyde should be directly formed
from 1b by an oxidative decarboxylation reaction, as
shown by path (a) of Scheme 2. In the case of the oxidation
of 1b, the two possible oxidation pathways (a) and (b) of
Scheme 2 seem to be operating simultaneously, with an
approximate ratio of 1:2.
The oxidation of 1d was completed in 1 h and occurred at
a much higher rate than that of 2d. The oxidation of 2d
afforded a conversion of only 25% after 24 h. As shown in
Table 5, the oxidation of 1d to 2d occurs very selectively at
the first stages of the reaction. However, in the reaction
medium, 2d undergoes a slow oxidation to 4d, and therefore
the aldehyde selectivity decreases with time.
2.3. Oxidation of 4-trifluoromethylmandelic acid, 4-tri-
fluoromethylbenzaldehyde and 4-trifluoromethylphenyl-
glyoxylic acid
The oxidation of 1d led selectively to the aldehyde 2d.
However, and in the absence of intermediate 3d, we cannot
conclude weather 2d is formed by a direct oxidative
decarboxylation of 1d (path (a), Scheme 2) or by the
decarboxylation of the keto acid intermediate (path (b)).
The carboxylic acid 4d is formed from the slow oxidation of
aldehyde 2d. As in the case of 1d, 4-hydroxymandelic, 1e,
led to the preferential formation of aldehyde 2e in 77%
selectivity (Table 1).
Figure 3 presents the kinetic evolution of the Bi(0)-
catalysed oxidation of 4-trifluoromethylmandelic acid, 1c,
4-trifluoromethylbenzaldehyde, 2c, and 4-trifluoromethyl-
phenylglyoxylic acid, 3c. The results indicate that the
oxidation of the keto acid 3c occurs at a much higher rate
than that of 1c, and a relatively slow oxidation of aldehyde
2c can be observed.
It can be concluded that 3c is an intermediate in the
oxidation of 1c to 4c, and 3c is not isolated in the reaction.
Table 4 indicates the results of the oxidations of 1c–3c.
After 1 h reaction, the keto acid 3c is almost completely
converted and the carboxylic acid 4c is formed with a
selectivity of 98%. This result is compatible with the
oxidation of 1c to 4c via 3c as the intermediate.
2.5. Proposed mechanisms
The above results indicate that in the case of the oxidation of
1a–c, the formation of the corresponding carboxylic acid 4
is issued from a first oxidation of the a-hydroxy acid, 1 to
the corresponding a-keto acid, 3, followed by a second
step of oxidative decarboxylation to 4. These successive
oxidation steps are catalysed by the system Bi(0)/O2 in
DMSO/AcOH. It has been recently reported, that under
the reaction conditions, the initial Bi(0) is dissolved in the
medium and forms a Bi(III) complex, which constitutes the
active oxidation species.24 In each oxidation step, the redox
couple Bi(III)/Bi(I) should be operating. The recycling of
the Bi(III) species is effected by molecular oxygen.
The aldehyde 2c is practically not formed in the oxidation of
either 1c or 3c. The aldehyde is only slowly oxidised to 4c,
Table 4. Oxidation of p-trifluoromethylmandelic acid, p-trifluoromethyl-
benzaldehyde and p-trifluoromethylphenylglyoxylic acid catalysed by
Bi(0)/O2
Substrate
Time (h)
Conversion (%)
Products formed
and selectivity
2c
3c
4c
A proposed catalytic cycle for the transformation of
mandelic acids 1 to their corresponding benzoic acids 4 is
shown in Scheme 3. The nature of the intermediates Bi(III)
or Bi(I) species, or the mode of coordination of O2 are not
yet known.
1c
2c
3c
24
24
1
97
37
90
1
–
2
–
–
–
99
95
98

I. Favier, E. Dun˜ach / Tetrahedron 59 (2003) 1823–1830
1827
Scheme 3. Catalytic cycle proposed for the oxidation of mandelic acids, 1 to their corresponding benzoic acids, 4.
According to Scheme 3, a first oxidation of Bi(0) to Bi(III) is
followed by the coordination of 1 to form a proposed
intermediate A. Other mechanisms are also possible for
the alcohol oxidation reaction, either concerted or non-
concerted. A redox reaction of A affords Bi(I) and the keto
acid 3. Further Bi(I) reoxidation to Bi(III) allows the
oxidative decarboxylation of the carboxylate intermediate B
to form the carboxylic acid 4 and CO2. The proposed
mechanism involving the passage 3 to 4 in Scheme 3 has
some similarities with the a-keto acid oxidation mecha-
nisms proposed by dioxygenase enzymes and their iron
synthetic models.37
This type of catalytic cycle is selectively operating in the
case of mandelic acid and of mandelic acids substituted by
electron-withdrawing substituents in the aryl ring.
The kinetic and preparative-scale results also indicated the
Scheme 4. Catalytic cycle proposed for the oxidation of mandelic acids, 1 to their corresponding benzaldehydes, 2.

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I. Favier, E. Dun˜ach / Tetrahedron 59 (2003) 1823–1830
Scheme 5. Proposed quinoid-type intermediates for mandelic acids possessing hydroxyl substituents on 2- or 4-positions of the aryl ring.
possibility, for substrates such as 1b and 1d to undergo a
direct oxidative decarboxylation to the corresponding
aldehydes 2. A catalytic cycle for the aldehyde formation
is proposed in Scheme 4.
A different slope in the Hammett correlation was obtained
for electron-rich and for electron-poor substrates, in
agreement with different operating mechanisms.
On the other hand, parallel competitive reaction studies
were carried out on the oxidation of some p-substituted
mandelic acid derivatives. In a first competition experiment
a 1:1 mixture of 4-trifluoromethylmandelic acid and
unsubstituted mandelic acid were reacted under the standard
reaction conditions for 24 h. The results are shown in Figure
5. It could be observed that mandelic acid under these
competitive conditions reacted slightly faster than alone,
no keto acid was present after 24 h (see Table 1 for
comparison) and the selectivity towards benzoic acid was of
85%.
In this case, intermediate A does not undergo alcohol
oxidation, but the cleavage of the C–C bond with loss of
CO2 and direct formation of derivatives 2, with recycling of
the Bi(III) species.
This catalytic cycle is preferred in the case of mandelic
acids possessing hydroxy substituents on the 2- or
4-positions of the aryl ring. The possible participation of
quinoid-type intermediates of type C (Scheme 5) can also be
considered and has already been proposed.38 The mecha-
nism shown in Scheme 4 should be partially operating in the
case of electron-donating substituents, such as the methoxy
group, as in the oxidation of 1b.
A slightly lower reactivity was observed for 4-trifluoro-
methylmandelic acid in this competitive experiment, with a
final selectivity in 4-trifluoromethylbenzoic acid of 88%.
Overall, the oxidation of a mixture of the two derivatives
afforded the same products with slight kinetic differences,
but in a less selective process.
Two different mechanistic pathways are therefore operating
in the oxidation of differently substituted mandelic acids.
To complete this study, a Hammett-type correlation was
obtained from the kinetic data with the Bi(0)/O2-catalysed
oxidation of mandelic acid substrates. The results are
presented in Table 6 and in Figure 4.
A second competitive experiment was carried out with a 1:1
mixture of 4-trifluoromethylmandelic acid and 4-hydro-
xymandelic acid for 5 h, and the results are presented in
Figure 6. In this reaction, an electron-poor substrate reacting
through path (b) in Scheme 2, according to the mechanism
proposed in Scheme 3 was reacted together with a 4-OH
substituted mandelic derivative, that was mainly affording
the corresponding aldehyde according to Schemes 4 or 5.
Table 6. Reaction half-time, rate constants and s values39 for mandelic acid
oxidations (see Eq. (1))
R
Substrate
t1/2 (h)
K (s21)£105a
log (k/k0)
s
H
1a
1b
1c
1e
1f
22
3
5
2
15
7
0.88 (k0)
6.42
3.85
9.63
1.28
0
0
p-OMe
p-CF3
p-OH
p-Cl
0.86
0.64
1.04
0.16
0.49
20.28
0.53
20.38
0.24
0.37
The results obtained indicated that the rate of conversion of
the 4-hydroxymandelic acid slowed down, and that of
4-trifluoromethylmandelic acid slightly increased. For both
compounds the selectivity towards the corresponding
aldehydes increased. Thus, the conversion of 4-hydroxy-
mandelic acid was of 57% after 6 h with a ratio 2e:4e of
89:11. For 4-trifluoromethylmandelic acid a conversion of
57% was reached after 5 h and the ratio 2c/4c was of 35:65.
This competitive experiment with two substrates reacting
through differently reaction pathways indicated that there is
a strong influence of the presence of one substrate on the
reactivity and the selectivity of the other one.
m-Cl
1g
2.75
a
The rate constant was taken as: k¼ln 2/t1/2
.
3. Conclusions
We report for the first time a systematic study on the
oxidation of differently substituted mandelic acid deriva-
tives, 1 with a Bi(0)/O2 catalytic system. The oxidation of 1
can afford either the corresponding carboxylic acids 4 or
the aldehydes 2. We could show that the formation of
acids 4 could involve the intermediate passage through the
Figure 4. Hammett representation for the oxidation of p-substituted
mandelic acid derivatives (Eq. (1)).

I. Favier, E. Dun˜ach / Tetrahedron 59 (2003) 1823–1830
1829
Figure 5. Oxidation of a 1:1 mixture of p-trifluoromethylmandelic acid and mandelic acid catalysed by Bi(0)/O2.
Figure 6. Oxidation of a 1:1 mixture of p-trifluoromethylmandelic acid and 4-hydroxymandelic acid catalysed by Bi(0)/O2.
corresponding keto acid intermediates, 3. Aldehydes 2 are
obtained through a different mechanism, the direct oxidative
decarboxylation. With the Bi(0)/O2 catalytic system, the
choice of one or other mechanism is essentially governed by
the nature of the substituent on the aryl ring of 1. Thus,
electron-withdrawing groups in the aryl moiety selectively
orientate towards the formation of the corresponding
carboxylic acids, via the keto acid intermediates. In sharp
contrast, when –OH or other electron-donating groups are
present as aryl substituent(s), particularly at the 2- and
4-positions, the formation of the aldehyde 2 is preferred and
the reaction rates are increased.
aqueous 0.1 M HCl solution saturated with NaCl, dried over
MgSO4 and filtered off. The products were analysed by
HPLC and H NMR and their spectral data compared to
those of authentic samples.
1
References
1. (a) Hodny, I.; Krob, V.; Smidrkal, J.; Bouskova, O. Czech. CS
277365 B6 (Cl. C07C47/575), 13 Jan 1993; Chem. Abstr.
1994, 121, 82716s. (b) Soucek, J.; Hora, A.; Kluger, A.;
Hedrlin, I.; Krob, V. Czech. CS 265937 B1 (Cl. C07C47/575),
Avr 13 1990; Chem. Abstr. 1992, 116, 83373m. (c) Maggioni,
´
P.; Minisci, F. Neth. Appl. NL 7905900 (Cl. C07C47/52), Fev.
4. Experimental
03 1981; Chem. Abstr. 1981, 95, 42661h. (d) Ube Industries,
Ltd. Jpn. Kokai Tokkyo Koho JP 82,112,346 (Cl. C07C47/
565); Chem. Abstr. 1982, 97, 181970n. (e) Umemura, Y.;
Enomiya, T.; Shiraishi, H.; Nakamura, T. Jpn. Kokai Tokkyo
Koho JP 8022614 (Cl. C07C49/245); Chem Abstr. 1980, 93,
114140w. (f) Umemura, S.; Takamitsu, N.; Enomiya, T.;
Shiraishi, Y.; Nakamura, T.; Harada, K.; Hashino, Y. Jpn.
Kokai Tokkyo Koho JP 7922334 (Cl. C07C47/56); Chem
Abstr. 1979, 90, 186590d.
The commercially available products were used without
further purification. The reactions were carried out under
atmospheric pressure of molecular oxygen. Mandelic acid
or its derivatives (1a–d) (2 mmol), was dissolved in DMSO
(5 mL) in the presence of Bi(0) powder (0.2 mmol) and
3 mmol of AcOH (50% aqueous solution). The mixture was
stirred at 1258C for 24 h or until the complete consumption
of the starting material, which was followed by HPLC
and/or by 1H NMR. The crude reaction mixture was
hydrolysed with 5 mL aqueous 1 M HCl solution saturated
with NaCl, and extracted with ethyl acetate (5£10 mL).
Organic phases were collected and washed twice with an
2. Teissere, P. Chimie des Substances Odorantes. Lavoisier Tec
& Doc, Paris, 1991.
3. Boelens, H. Indian Perfum. 1968, 12, 28–32.
4. (a) Barthel, W. F.; Leon, J.; Hall, S. A. J. Org. Chem. 1954, 19,

1830
I. Favier, E. Dun˜ach / Tetrahedron 59 (2003) 1823–1830
485–489. (b) Tsantrizos, Y. S.; Ogilvie, K. K. Can. J. Chem.
1991, 69, 772–778.
18. Singh, C. M.; Dutt, D. K.; Singh, S. B. J. Indian Chem. Soc.
1993, 70, 190–192.
5. (a) Cooper, R. D. G.; Jose, F.; McShane, L.; Koppel, G. A.
Tetrahedron Lett. 1978, 26, 2243–2246. (b) Rosenheim, M. L.
Lancet 1935, 1, 1032–1037.
19. Gupta, K. C.; Kumar, P.; Behari, K. Bull. Soc. Chim. Fr. 1987,
2, 232–236.
20. Blay, G.; Fernandez, I.; Formentin, P.; Pedro, J. R.; Rosello,
L. A.; Ruiz, R.; Journaux, Y. Tetrahedron Lett. 1998, 39,
3327–3330.
6. Roeding, J.; Teichmueller, E.; Seigfried, B. G. Ger. Offen.
1995 GWXXBX DE 4420727 A1 19951221 Chem. Abstr.
1995, 124, 185169.
21. Zevaco, T.; Dun˜ach, E.; Postel, M. Tetrahedron Lett. 1993, 34,
2601–2604.
7. Sidot, C.; Christidis, Y. Eur. Pat. Appl. EP 429,316 (Cl.
C07D317/54); Chem Abstr. 1991, 115, 92249g.
22. Le Boisselier, V.; Dun˜ach, E.; Postel, M. J. Organomet. Chem.
1994, 482, 119–123.
8. (a) Kalikar, R. G.; Deshpande, R. S.; Chandalia, S. B. J. Chem.
Technol. Biotechnol. 1987, 106, 49713f. (b) Bauer, K.; Grabe,
P. Common Fragance and Flavor Materials, Preparation,
Properties and Uses; VCH: Lausanne, 1985.
23. Le Boisselier, V.; Coin, C.; Postel, M.; Dun˜ach, E.
Tetrahedron 1995, 51, 4991–4996.
24. Coin, C.; Le Boisselier, V.; Favier, I.; Postel, M.; Dun˜ach, E.
Eur. J. Org. Chem. 2001, 735–740.
9. (a) Wuthrick, M. F.; Maliverney, C. Industrial Chemistry
Library; Desmurs, J. R., Ratton, S., Eds.; Elsevier:
Amsterdam, 1996; Vol. 8, pp 343–349. (b) Perrin, R.; Scharff,
J. P. Chimie Industrielle; Masson: Paris, 1993; Vol. 2. pp
841–842.
25. Rigby, W. J. Chem. Soc. 1950, 1907–1913.
26. Tymonko, S. A.; Nattier, B. A.; Mohan, R. S. Tetrahedron
Lett. 1999, 40, 7657–7659.
27. Eash, K. J.; Pulia, M. S.; Wieland, L. C.; Mohan, R. S. J. Org.
Chem. 2000, 65, 8399–8401.
10. (a) Santaniello, E.; Manzocchi, A.; Farachi, C. Synthesis 1980,
563–565. (b) Nwaukwa, S. O.; Keehn, P. M. Tetrahedron Lett.
1982, 23, 3135–3138. (c) Beebe, T. R.; Adkins, R. L.;
Belcher, A. I.; Choy, T.; Fuller, A. E.; Morgan, V. L.;
Sencherey, B. B.; Russell, L. J.; Yates, S. W. J. Org. Chem.
1982, 47, 3006–3008. (d) Firouzabadi, H.; Sardarian, A. R.;
Naderi, M.; Vessal, B. Tetrahedron 1984, 40, 5001–5004.
(e) Sen Gupta, K. K.; Banerjee, A.; Chatterjee, H. Tetrahedron
1992, 48, 5323–5330. (f) Rigby, W. J. Chem. Soc. 1950,
1907–1913. (g) Stange, H.; Matschiner, H.; Mendow, E.;
Schunke, D.; Nauwald, G. Ger. (East) DD 289516 A5 (Cl.
C07C47/58, C07C47/565, C07C45/32); Chem Abstr. 1991,
115, 158717s.
28. Komatsu, N.; Taniguchi, A.; Uda, M.; Suzuki, H. Chem.
Commun. 1996, 1847–1848.
29. Bhatia, K. A.; Eash, K. J.; Leonard, N. M.; Oswald, M. C.;
Mohan, R. S. Tetrahedron Lett. 2001, 42, 8129–8132.
30. Le Roux, C.; Dubac, J. Synlett 2002, 181–200.
31. Mohammadpoor-Baltork, I.; Aliyan, H.; Khosropour, A. R.
Tetrahedron 2001, 57, 5851–5854.
32. Le Roux, C.; Ciliberti, L.; Laurent-Robert, H.; Laporterie, A.;
Dubac, J.; Desmurs, J. R. Synlett 1998, 1249–1251.
33. Robert, H.; Garrigues, B.; Dubac, J. Tetrahedron Lett. 1998,
39, 1161–1164.
34. Sabitha, G.; Venkata Reddy, E.; Yadav, J. S. Synthesis 2002,
409–412.
11. Mahapatro, S. N.; Panigrahi, A. K.; Panda, R.; Patro, D. M.
Inorg. Chem. 1984, 23, 4119–4120.
35. For a review see for example Suzuki, H.; Ikegami, T.;
Matamo, Y. Synthesis 1997, 249–267.
´
36. Favier;, I.; Giulieri, F.; Dun˜ach, E.; Hebrault, D.; Desmurs,
12. Walling, C.; Amarnath, K. J. Am. Chem. Soc. 1982, 104,
1185–1189.
13. Krumpolc, M.; Rocek, J. Inorg. Chem. 1985, 24, 617–621.
14. Banerjee, K. K. Tetrahedron 1973, 29, 1401–1403.
15. Higuchi, M.; Ikeda, I.; Hirao, T. J. Org. Chem. 1997, 62,
1072–1078.
J. R. Eur. J. Org. Chem. 2002, 1984–1988.
37. Chiou, Y. M.; Que, Jr. L. Angew. Chem. 1994, 106,
1969–1971.
38. Taran, F.; Renard, P. Y.; Bernard, H.; Mioskowski, C.;
Frobert, Y.; Pradelles, P.; Grassi, J. J. Am. Chem. Soc. 1998,
120, 3332–3339.
16. Schouteeten, A.; Christidis, Y.; Vallejos, J. C. EP 47693 A1,
Mar. 17 1982; Chem. Abstr. 1982, 96, 217481z.
17. Fiege, H.; Wedemeyer, K.; Bauer, K.; Mollenken, R. Ger.
´
Offen. 2,824,407 (Cl. C07C65/20), Dec. 13 1979, Appl.;
Chem. Abstr. 1980, 92, 180833e.
39. March, J. Advanced Organic Chemistry, 3rd ed., Wiley: New
York, 1985; p 244.