From allylic alcohols to saturated carbonyls using Fe(CO)5 as catalyst: Scope and limitation studies and preparation of two perfume components

Article abstract of DOI:10.1016/S0040-4020(01)00114-4

The direct conversion of allylic alcohols to saturated carbonyls, using Fe(CO)₅ as a catalyst, offers good synthetic potential. Mono-, di- and even trisubstituted alkenes bearing various alkyl, aryl and electronwithdrawing groups on the allylic system give good to excellent yields of rearranged products. Limitations occur mainly with polyunsaturated derivatives. This reaction was applied to a short and efficient synthesis of cyclamen aldehyde and foliaver.

Full text of DOI:10.1016/S0040-4020(01)00114-4

TETRAHEDRON
Pergamon
Tetrahedron 57 (2001) 2379±2383
From allylic alcohols to saturated carbonyls using
Fe(CO)5 as catalyst: scope and limitation studies
and preparation of two perfume components
a,b
Hassan Cherkaoui, Mohammed Sou®aoui and Rene Gree
b
a,p
Â
Â
a
Á Â Â Â
Laboratoire de Syntheses et Activations de Biomolecules, CNRS UMR 6052, ENSCR, Avenue du General Leclerc,
35700 RennesBeaulieu, France
Laboratoire de Chimie des Plantes et de Synthese Organique et Bio-Organique, Faculte des Sciences, Universite Mohammed V,
B.P.1014 R.P.Rabat, Morocco
b
Á
Â
Â
Received 4 December 2000; revised 12 January 2001; accepted 26 January 2001
AbstractÐThe direct conversion of allylic alcohols to saturated carbonyls, using Fe(CO)5 as a catalyst, offers good synthetic potential.
Mono-, di- and even trisubstituted alkenes bearing various alkyl, aryl and electronwithdrawing groups on the allylic system give good to
excellent yields of rearranged products. Limitations occur mainly with polyunsaturated derivatives. This reaction was applied to a short and
ef®cient synthesis of cyclamen aldehyde and foliaver. q 2001 Elsevier Science Ltd. All rights reserved.
The conversion of allylic alcohols to saturated carbonyl
compounds is a useful synthetic process, usually requiring
a two-step sequence of oxidation (reduction) followed by
reduction (oxidation). A one pot catalytic transformation of
allylic alcohols to saturated carbonyl compounds by internal
redox processes (Scheme 1) is an attractive alternative strat-
egy: it is a complete atom economy process, which may also
minimise the number of protection±deprotection steps often
required for such transformations.1a
involving in the key step, an hydride migration in the coor-
dination sphere of the metal (Scheme 2).2c,e
However, only limited studies have been reported later
regarding the possible synthetic uses of this transformation.
Simple alkyl derivatives2b and bicyclic systems2d±g have
been examined. Extension to some ethers and esters have
also been reported.2f,g As part of our program of novel
preparation and synthetic applications of transition metal
enolates,3 we felt it necessary to perform a systematic
study on the scope and limitations of this transformation
induced by iron carbonyls. Fe(CO)5 was selected for our
Various transition metal complexes derivatives, including
Ru, Rh, Co, Ni, Mo, Ir, Pt, have been already used for the
transformation of A into B.1 However, many of them are
expensive and (or) not easily accessible; furthermore, they
are often of restricted scope with regard to the degree of
substitution of the double bond. Harsh reaction conditions
are also often required.
Iron carbonyl derivatives have been known for a long time
as being able to perform this transformation.2 Furthermore,
labelling experiments have clearly established a mechanism
Scheme 1. Isomerization of allylic alcohols to ketones.
Keywords: allylic alchols; isomerization; catalysis; iron.
Corresponding author. Tel.: 133-2-9987-1383; fax: 133-2-9987-1384;
p
Scheme 2. Mechanism of Fe(CO)5 induced isomerization.
e-mail: rene.gree@ensc-rennes.fr
0040±4020/01/$ - see front matter q 2001 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020(01)00114-4

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H. Cherkaoui et al. / Tetrahedron 57 (2001) 2379±2383
Table 1. Isomerization of simple models with alkyl and aryl groups
Another competitive double bond migration was observed
in the case of alcohol 13. Reaction of 13 gave the desired
ketone 14a (59% yield) together with a mixture of unsatu-
rated alcohols 14b resulting from the migration of the
double bond along the pentyl chain (Scheme 3). The
NMR data indicated a complex mixture of regio- and stereo-
isomers, which could not be separated by chromatography.
However, here again, under the same reaction conditions,
this mixture of isomers slowly isomerized to desired ketone
14a.
The second family of allylic alcohols studied were
compounds possessing an aromatic group on the double
bond. As indicated in Table 2, all secondary alcohols gave
the desired ketones in excellent yields.
For primary alcohols, the results depend upon substitution:
cinnamyl alcohol gave a complex reaction mixture with the
desired aldehyde 24 isolated in only 38% yield. It was estab-
lished that this derivative is not stable under the reaction
conditions, giving a mixture of unidenti®ed products. A
completely different result was obtained in the case of
alcohol 25, giving 26 in excellent yield. Due to the steric
hindrance by the methyl group, the corresponding aldehyde
is probably more stable. It is interesting to notice that 25 is
the ®rst example of an allylic alcohol with substituents both
in a and b position on the double bond which could be
isomerized under transition metal mediated catalysis.
Since several perfume components have this general struc-
ture 26, two of them were selected in order to test the
applicability of this methodology: cyclamen aldehyde and
foliaver.7
studies, as it is the most economical and easily accessible
member of this family of reagents. Furthermore, it is also
very ef®cient for the preparation of diene tricarbonyl iron
complexes under irradiative conditions.4
Allylic alcohols with hydrogens or alkyl substituents on the
double bond were studied ®rst (Table 1). The reaction was
found to be very ef®cient in the case of alcohols having
methyl groups in a or b position on the double bond and
alkyl chains or aromatic groups on the secondary alcohol
function. In each case, good to excellent yields were
obtained using 1±5% catalyst.
Allylic alcohols bearing two alkyl substituents in geminal
position on the double bond are known to be among the
most dif®cult compounds with regards to this isomerization
process.1a The reported examples were performed mainly
with geraniol: low yields were obtained with Ir complexes,5
low to moderate yields with Ni derivatives,1e while TPAP
proved to be recently successful in this rearrangement.1c For
the gem-dimethyl derivative 11, the reaction is complete
after 4 h, giving a mixture of 12a and 12b separated by
chromatography (Scheme 3). For this sterically more
hindered molecule, competition for hydride migration
occurs between one hydrogen from the methyl group and
the other hydrogen from the secondary alcohol. Such migra-
tions of double bonds along alkyl chains and induced by iron
carbonyls are well known in the literature.6 However, from a
synthetic point of view it is important to notice that pure
homoallylic alcohol 12b, under previously described reaction
conditions, also isomerized slowly to the desired ketone 12a.
The starting alcohols 29 were prepared from commercially
available aldehydes by standard procedures and in good
overall yields (Scheme 4).
Using 5% molar catalyst, the isomerization of 29a gave 30a
in quantitative yield. In the case of 29b, the isomerization
followed by the ketal deprotection using formic acid8 gave
foliaver 300b. Both perfume components were obtained
Table 2. Isomerization of cinnamyl type derivatives
Scheme 3. Isomerization of allylic alcohols 11 and 13.

H. Cherkaoui et al. / Tetrahedron 57 (2001) 2379±2383
2381
Scheme 5. Allylic alcohols which do not rearrange under Fe(CO)5 catalysis.
Scheme 4.
easily and in excellent overall yields (93% for 30a and 85%
for 300b) from aldehydes 27.
isomerization occurs under the reaction conditions and
that the Z isomer is, at least in part, an intermediate in
the rearrangement of 37a. The reason for this peculiar
behaviour of latter derivative has not yet been established.
Studies were then extended to alkenes functionalized with
electron withdrawing groups; the corresponding results are
given in Table 3. The reaction was found compatible with an
ester group either in a or b position on the alkene. In both
cases, good yields of the desired ketoesters were obtained.
More surprisingly, the a,b unsaturated ketone 35 gave, with
only 5% catalyst and after 3 h, the diketone 36 in 70% yield.
It is well established that conjugated enones give easily
stable h2 or h4 complexes on reaction with iron carbonyls.9
Therefore, it is of note that in the case of 35, hydride migra-
tion from the allylic alcohol portion of the molecule occurs
preferentially. To the best of our knowledge, such a compe-
tition has not been observed previously.
Finally, several examples of polyunsaturated alcohols were
studied (Scheme 5).
Not surprisingly, in the case of a,b unsaturated dienols 39 or
41, no transformation to carbonyl derivatives was observed.
The only isolated compounds (in yields corresponding to the
amount of catalyst used) were the known h4 complexes 40
and 42 (as a mixture of c-exo and c-endo stereoisomers, in
latter case).10 For such dienols, the formation of the very
stable h4 complexes is preferred over the hydride migration.
Several other types of polyunsaturated systems have been
studied, however, without success. In the cases of 1,4
dienols 43 and 44, propargylic alcohol 45, as well as
enyne 46, only starting material was recovered. Using
higher catalyst loading (until 25% M) gave similar results
with only minor quantities of unidenti®ed degradation
products. These results indicate that, using iron carbonyls
as catalysts, the isomerization process has clear limitations
with regard to the number of unsaturations in the starting
allylic alcohols. Finally, another limitation has been
encountered in the case of tri¯uoromethylated alcohols
47a and 47b: no reaction was observed and only the starting
material was recovered, even using higher catalyst loading.
This is probably due to the strong electron withdrawing
effect of the CF3 group, inhibiting hydride migration leading
to the p-allyl iron intermediate, which is a key step in this
reaction (Scheme 1).
The cyano group is also compatible with this isomerization,
however 10% catalyst was necessary to obtain good rates for
this reaction. The Z isomer 37b reacted faster and gave
ketone 38 in excellent yield. However, the corresponding
E isomer 37a exhibited a slower rate for the transformation
and gave a lower yield. Furthermore, after 6 h it was
possible to characterize (by TLC and NMR) in the reaction
mixture, about 6% of the Z isomer. This indicates that E±Z
Table 3. Isomerization of derivatives with electron withdrawing
substituents
In conclusion, we have shown that Fe(CO)5 is an
inexpensive and versatile catalyst for the isomerization of
allylic alcohols to saturated carbonyl compounds. Its scope
appears relatively broad for alkenes bearing alkyl, aryl or
electron withdrawing substituents, though competitive
processes may occur in some cases. However, severe
limitations exist for polyunsaturated derivatives. Finally,
we have reported a new and ef®cient preparation of two
perfume components using, as a key step, this isomerization
reaction.

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H. Cherkaoui et al. / Tetrahedron 57 (2001) 2379±2383
1. Experimental
[(OCH2CH3)2]; 14.24, 14.00 [(OCH2CH3) and (CvCCH3)].
HRMS (EI): for C17H24O4, [M]z1: calcd: 292.1676; found:
292.1673. Anal. calcd for C17H24O4: C, 69.83; H, 8.27.
Found: C, 69.91; H, 8.22.
1.1. General
Except for 21, all the starting allylic alcohols are already
known in the literature. They were prepared by standard
procedures:
1.2.2. Allylic alcohol 29b. To a solution of ester 28b (4 g,
13.7 mmol) in anhydrous ether (100 ml) was added drop-
wise under nitrogen at 2358C, a 1 M solution of Dibal-H in
hexanes (27.4 ml, 27.4 mmol). After 15 min stirring at this
temperature, water (100 ml) was added and the reaction
mixture was allowed to come back to room temperature.
After addition of NaOH (2.4 g), the allylic alcohol was
extracted with ether (3£50 ml). The organic phases were
washed with brine, water, dried (MgSO4) and concentrated
in vacuo. The alcohol was puri®ed by ¯ash chromatography
using 1:1 mixture of ether and low boiling petroleum ether
as eluent. 29b: 2.95 g, 86% yield. TLC: Rfˆ0.25 (E/Ep:
50:50). 1H NMR: (CDCl3, 400 MHz): d 7.42±7.44 (d,
Jˆ8.1 Hz, 2H arom); 7.26±7.28 (d, Jˆ8.1 Hz, 2H arom);
6.51 [broad s, 1H, ±CHvC(CH3)]; 5.50 (s, 1H,
±CH(OEt)2); 5.50 [s, 1H, ±CH(OCH2CH3)2]; 4.15 (m, 2H,
addition of Grignard or organolithium derivatives on the
corresponding aldehyde for 1, 3, 5, 7, 9, 11, 15, 17, 19, 21,
41, 43, 45, 46;
reduction by LiAlH4 of the corresponding propargylic
alcohol for 13;
for the primary alcohols, Dibal-H reduction of the corre-
sponding esters for 29a, 29b while 23, 25 and 39 are
commercially available;
a Baylis±Hilman reaction for 33;
Wittig reactions, starting from 2-hydroxy hexanal,11 for
31, 35, 37; in latter case, the (7:3) mixture of E (37a) and
Z (37b) isomers could be separated by ¯ash chroma-
tography on silica gel;
reaction of Ruppert's reagent (Me3SiCF31F2) on corre-
sponding aldehydes for 47
±CH2OH);
3.58
[dq,
Jˆ7.12,
14.2 Hz,
4H,
±CH(OCH2CH3)]; 2.22 (s, 1H, OH); 1.88 (s, 3H, CH3);
1.24 [t, Jˆ6.8 Hz, ±(OCH2CH3)2] 13C NMR: (CDCl3,
100 MHz): d 137.87, 137.55, 136.95, 128.61, 126.32,
124.42 (CPh and CvC); 101.38 [±CH(OEt)2]; 68.67
(±CH2OH); 60.99 [± (OCH2CH3)2]; 15.22 (±CHvCCH3);
15.09 [± (OCH2CH3)2]. HRMS (EI): for C15H22O3, [M]z1:
calcd: 250.1569; found: 250.1557. Anal. calcd for C15H22O:
C, 71.96; H, 8.85. Found: C, 71.49; H, 8.88.
.
1.1.1. Allylic alcohol 21. From a-methylcinnamaldehyde
(3 g, 20.5 mmol) and using 1.5 equiv. of n-C5H11MgBr in
THF at 2508C, allylic alcohol 21 was isolated after ¯ash
chromatography on silica gel using a 1:4 mixture of ether
(E) and low boiling (,608C) petroleum ether (Ep) as eluent.
21: 3.7 g, 79% yield. TLC: Rfˆ0.31 (E/Ep: 30:70). 1H NMR
(CDCl3, 400 MHz): d 7.19±7.34 (m, 5H arom); 6.47 (s, 1H,
H1); 4.16 (dt, Jˆ6.9, 1.3 Hz, 1H, H3); 1.85 (d, Jˆ1.3 Hz,
3H, CH3); 1.72 (broad s, 1H, OH);1.60±1.65 (m, 2H, CH2);
1.24±1.45 (m, 6H, CH2);.89 (t, Jˆ7.1 Hz, 3H, CH3). 13C
NMR (CDCl3, 100 MHz): d 140.37, 137.55, 128.92,
128.05, 128.05, 126.35, 125.70 (CPh and CvC); 77.90
(C3); 34.98, 31.75, 25.46, 22.59 (CH2); 14.03, 13.05
(CH3). HRMS (EI): for C15H22O, [M]z1: calcd: 218.1671;
found: 218.1675. Anal. calcd for C15H22O: C, 82.51; H,
10.15. Found: C, 81.98; H, 10.17.
1.3. Representative procedure for isomerization:
preparation of foliaver
1.3.1. Monoacetal 30b. Caution: Fe(CO)5 is known to be
toxic, therefore all reactions involving this reagent should
be carried out under a ventilated fume hood.
Argon was bubbled (15 min) through a pentane solution
(20 ml) of alcohol 29b (1.26 g, 5 mmol) in a 50 ml pyrex
¯ask. Then Fe(CO)5 (33 ml, 5% molar) was added via a
syringe. The reaction mixture was irradiated, under
magnetic stirring, by an external UV lamp (Phillips HPK
125W) until the disappearance of allylic alcohol (TLC
monitoring): after 1 h, the reaction was complete. The reac-
tion mixture was ®ltered on a short SiO2 plug and the
solvent evaporated. The carbonyl derivative 30b was puri-
®ed by ¯ash chromatography on silica gel using a 5:95
mixture of ether and low boiling petroleum ether as eluent.
1.2. Representative procedure: preparation of foliaver
1.2.1. Ester 28b. A solution of aldehyde 27b (1.9 g,
8.93 mmol) and a-methyl carbethoxymethylenetriphenyl-
phosphorane (3.88 g, 10.7 mmol) in CH3CN(60 ml) was
heated under re¯ux for 45 min. After distillation of solvent
under vacuo, the ester was isolated by ¯ash chromatography
on silica gel using a 3:7 mixture of ether and low boiling
petroleum ether as eluent. 28b: 2.58 g, 97% yield. TLC:
Rfˆ0.60 (E/Ep: 50:50). 1H NMR(CDCl3, 400 MHz): d
7.68 [broad s, 1H, ±CHvC(CH3)]; 7.38±7.51 (m, 4H
arom); 5.51 [s, 1H,±CH(OEt)2]; 4.27 (q, Jˆ7.1 Hz, 2H,
±CO2CH2); 3.64 (q, Jˆ7.1 Hz, 1H, OCH2CH3); 3.62 (q,
Jˆ7.1 Hz, 1H, OCH2CH3); 3.56 (q, Jˆ7.1 Hz, 1H,
OCH2CH3); 3.54 (q, Jˆ7.1 Hz, 1H, OCH2CH3); 2.11 [d,
Jˆ1.2 Hz, 3H, ±CHvC(CH3)]; 1.35 (t, Jˆ7.1 Hz, 3H,
±CO2CH2CH3); 1.24 [t, Jˆ7.1 Hz, 6H, CH(OCH2CH3)2].
13C NMR (CDCl3, 100 MHz): d 168.56 (CO2Et), 139.07,
138.23, 135.85, 129.44, 128.68, 126.57 (CPh and CvC);
101.02 [CH(OEt)2]; 61.02, 60.79 (OCH2); 15.11
1
30b: 1.14 g, 90% yield. TLC: Rfˆ0.52 (E/Ep: 50:50). H
NMR (CDCl3, 400 MHz): d 9.71 (s, 1H, CHO); 7.40 (d,
Jˆ7.9 Hz, 2H arom); 7.16 (d, Jˆ8.1 Hz, 2H arom); 5.48
[s, 1H, ±CH(OEt)2]; 3.55 (m, 4H, (OCH2CH3)2); 3.08 (dd,
Jˆ5.6 Hz, 1H, ± CHaHbPh); 2.65 (m, 1H, ±CHCH3);
2.59(dd, 1H,
±
CHaHbPh); 1.23 [t, Jˆ7.1 Hz; 6H,
±CH(CH3)2]; 1.075 (d, Jˆ6.8 Hz, 3H, ±CH3). 13C NMR
(CDCl3, 100 MHz): d 204.24 (±CHO), 138.82, 137.18,
128.74, 126.72 (CPh); 101.33 [±CH(OEt)2]; 60.94
[±CH(OCH2CH3)2]; 47.90 (±CCHO); 36.22 (±CH2);15.09
[±CH(OCH2CH3)2]; 13.08 (±CH3). HRMS (EI): C15H22O3,
the intensity of the molecular ion was too low to be
measured. For: [Mz2´OCH2CH3]1 (C13H17O2): calcd:

H. Cherkaoui et al. / Tetrahedron 57 (2001) 2379±2383
2383
recent data see: (b) Ru Backvall, J. E.; Andreasson, U.
Tetrahedron Lett. 1993, 34, 5459±5462. (c) Marko, I. E.;
Gautier, A.; Tsukazaki, M.; Llobet, A.; Plantalech-Mir, E.;
Urch, C. J.; Brown, S. M. Angew. Chem., Int. Ed. 1999, 38,
1960±1962. (d) Slugovc, C.; Ruba, E.; Schmid, R.; Kirchner,
K. Organometallics 1999, 18, 4230±4233. (e) Ni Bricourt, H.;
Mon¯ier, E.; Carpentier, J.-F.; Mortreux, A. Eur. J. Inorg.
Chem. 1998, 1739±1744.
205.1228; found: 205.1234. Anal. calcd for C15H22O: C,
71.96; H, 8.85. Found C, 71.68; H, 8.44.
1.3.2. Foliaver 300b. A solution of acetal 30b (0.5 g,
2 mmol) in pure formic acid (1 ml) was heated to 608C
during 45 min. After addition of a saturated Na2CO3 solu-
tion and extraction with ether (3£30 ml), the organic phases
were washed with brine and dried (MgSO4). Foliaver was
puri®ed by ¯ash chromatography on SiO2 using a 1:1
mixture of ether and low boiling petroleum ether as eluent.
2. (a) Emerson, G. F.; Pettit, R. J. Am. Chem. Soc. 1963, 84,
4591±4592. (b) Damico, R.; Logan, T. J. J. Org. Chem.
1967, 32, 2356±2358. (c) Hendrix, W. T.; Cowherd, F. G.;
von Rosenberg, J. L. J. Chem. Soc. (D) 1968, 97±99.
(d) Cowherd, F. G.; von Rosenberg, J. L. J. Am. Chem. Soc.
1969, 91, 2157±2158. (e) Strauss, J. U.; Ford, P. W.
Tetrahedron Lett. 1975, 33, 2917±2918. (f) Iranpoor, N.;
Imanieh, H.; Forbes, E. J. Synth. Commun. 1989, 19, 2955±
2961. (g) Iranpoor, N.; MottaghineJad, E. J. Organomet.
Chem. 1992, 423, 399±404.
1
300b: 0.3 g, 86% yield. TLC: Rfˆ0.27 (E/Ep: 50:50). H
NMR (CDCl3, 400 MHz): d 9.97 (s, 1H, ±CHO); 9.71 (d,
Jˆ1.0 Hz, 1H, ±CHCHO); 7.81 (d, Jˆ8.1 Hz, 2H arom);
7.34 (d, Jˆ8.1 Hz, 2H arom); 3.17 (dd, Jˆ12.7 Hz, 1H,
±CHaHbPh); 2.65±2.77 (m, 1H, ±CHCH3); 2.66(dd, 1H,
±CHaHbPh); 1.11 (d, Jˆ6.8 Hz, 3H, ±CH3). 13C NMR
(CDCl3, 100 MHz):
d
203.45 (±CHCHO), 191.87
(±PhCHO); 146.33, 134.88, 130.01, 129.70 (CPh); 47.68
(±CCHO); 36.55 (±CH2); 13.26 (±CH3).
3. Crevisy, C.; Wietrich, M.; Le Boulaire, V.; Uma, R.; Gree, R.
Tetrahedron Lett., 2001, 42, 395±398.
Except 22, all carbonyl compounds obtained via this pro-
cedure are already known in the literature (from Beilstein
data base). They have spectroscopical data (IR, 1H and 13C
NMR) in good agreement with the indicated structures and
with literature data.
4. Gree, R.; Lellouche, J.-P. In Advances in Metallo-Organic
Chemistry; Jai Press, 1995; Vol. 4, pp 125±273 (and refer-
ences cited therein).
5. Baudry, D.; Ephritikine, M.; Felkin, H. Nouv. J. Chim. 1978,
2, 355±356.
6. (a) Asinger, F.; Berg, O. Chem. Ber. 1955, 88, 445±451.
(b) Manuel, T. A. J. Org. Chem. 1962, 27, 3941±3945. See
also: (c) Barborak, J. C.; Dasher, L. W.; McPhail, A. T.;
Nichols, J. B., Onan, K. D. Inorg. Chem., 1978, 17, 2936±
2943 and references cited therein.
1
1.3.3. Ketone 22. TLC: Rfˆ0.60 (E/Ep: 30:70). H NMR
(CDCl3, 400 MHz): d 7.14±7.26 (m, 5H arom); 2.96 (dd,
Jˆ7.1, 13.4 Hz, 1H, ±PhCHaHb); 2.82 (m, 1H,
±CHaHbCH); 2.54 (dd, 1H, ±PhCHaHb); 2.38 (dt, Jˆ7.3,
14.7 Hz, 1H, ±COCHdHe); 1.14 (dt, 1H, ±COCHdHe);
1.44±1.51 (m, 2H, ±COCHdHeCH2); 1.12±1.30 [m, 4H,
±(CH2)2CH3]; 1.07 (d, Jˆ6.8 Hz, 3H, ±CHCH3); 0.85 (d,
Jˆ7.1 Hz, 3H, ±CH2CH3). 13C NMR (CDCl3, 100 MHz): d
214.38 (±CO), 139.79, 128.89, 128.30, 126.10 (CPh); 48.02
(±CHCH3), 41.95, 30.07, 31.27, 23.09, 22.38 (±CH2); 16.85
(±CHCH3); 13.85 (±CH3). HRMS (EI) for C15H22O, [M]z1:
calcd: 218.1671; found: 218.1675. Anal. calcd for C15H22O:
C, 82.51; H, 10.15. Found: C, 82.43; H, 10.07.
7. (a) Chalk, A. J.; Magennis, S. A. J. Org. Chem. 1976, 41,
1206±1209. For a recent review on odorants see: (b) Kraft,
P.; Bajgrowicz, J. A.; Denis, C.; Frater, G. Angew. Chem., Int.
Ed. 2000, 39, 2980±3010.
8. Gorgues, A. Bull. Soc. Chim. Fr. 1974, 529±530.
9. (a) Koerner von Gustorf, E. A.; Grevels, F. W.; Fischer, I. The
Organic Chemistry of Iron; Vol. 1; Academic Press: New
York, 1978. (b) Koerner von Gustorf, E. A.; Grevels, F. W.;
Fischer, I. The Organic Chemistry of Iron; Vol. 2; Academic
Press: New York, 1981. (c) Davies, S. G. Organotransition
Metal Chemistry: Applications to Organic Synthesis;
Pergamon: Oxford, 1982. (d) Pearson, A. J. Metallo-Organic
Chemistry; Wiley: New York, 1985.
Acknowledgements
We thank Dr I. Storet (Rhodia) for useful suggestions deal-
ing with the perfume components, Dr M. Bartberger for very
fruitful discussions and M. Prakesch for his help during the
preparation of the manuscript.
10. Clinton, N. A.; Lillya, C. P. J. Am. Chem. Soc. 1970, 92,
3058±3064.
11. We used the crude aldehyde obtained by oxidation of 1,2
hexanediol following Torii's procedure: Inokuchi, T.;
Matsumoto, S.; Nishiyama, T.; Torii, S. J. Org. Chem. 1990,
55, 462±466.
References
1. (a) Trost, B. M.; Kulawiec, R. J. J. Am. Chem. Soc. 1993, 115,
2027±2036 (and references cited therein). For some more