Synthesis of novel fragrant molecules 6-methoxy-2,6-dimethyl heptanol derivatives

Article abstract of DOI:10.14233/ajchem.2014.16089

Methoxy elgenol as an important class of monomeric spices, has rich and pleasing aroma of sandalwood and flowers. We have synthesized a series of derivatives of methoxy elgenol, which have the similar structure of (CH ₃)₂COCH₃(CH₂)₃CHCH ₃CHROH, expecting sandalwood odor molecules. Actually, the novel compounds possess a wide odor range, different from methoxy elgenol, from typically melon odorants to derivatives with floral, marine, fruity, faint scent or even metallic aroma. This work describes the methoxylation of methyl heptenone and Darzens condensation to form 6-methoxy-2,6-dimethyl-heptanol (4), which is an important starting material for synthesizing the derivatives of 6-methoxy-2,6-dimethyl-heptanol (5), namely 8-methoxy-4,8-dimethylnoman-3-ol (5a), 9-methoxy-5,9-dimethyldecan-4- ol (5b), 8-methoxy-2,4,8-dimethyl-decan-3- ol (5c), 10-methoxy-6,10-dimethylundecan-5-ol (5d), 9-meth-oxy-2,5,9- trimethyldecan-4- ol (5e), 10-methoxy-2,6,10-trimethylundecan-5-ol (5f), 1-cyclopentyl-6-methoxy-2,6-dimethyl-heptan-1-ol (5g), 2-methoxy-2,6- dimethyltridecan-7-ol (5h), 1-cyclohexyl-6-methoxy-2,6-dimethylheptan-1-ol (5i), 9-methoxy-5,9-dimethyldec-1-en-4-ol (5j), pleasant smell emanating from 10-methoxy-2,6,10-trimethylundecan-5-ol (5f) with elegant melon and delicatesea breeze, 2-methoxy-2,6- dimethyltridecan-7-ol (5h) with faint scent, fruity and oce-an-like taste and 9-methoxy-5,9-dimethyldec-1-en-4-ol (5j) with melon and elegant floral.

Full text of DOI:10.14233/ajchem.2014.16089

Asian Journal of Chemistry; Vol. 26, No. 13 (2014), 3958-3962
ASIAN JOURNAL OF CHEMISTRY
http://dx.doi.org/10.14233/ajchem.2014.16089
Synthesis of Novel Fragrant Molecules 6-Methoxy-2,6-dimethyl Heptanol Derivatives
*
XIAODAN GUO, QUAN LI, ZHIJIAN WANG and WEIMIN JIA
School of Perfume and Aroma Technology, Shanghai Institute of Technology, Shanghai, P.R. China
*Corresponding author: Fax: +86 21 34020519; E-mail: jiawm1964@163.com; 15618492372@163.com
Received: 23 July 2013;
Accepted: 4 September 2013;
Published online: 23 June 2014;
AJC-15382
Methoxy elgenol as an important class of monomeric spices, has rich and pleasing aroma of sandalwood and flowers. We have synthesized
a series of derivatives of methoxy elgenol, which have the similar structure of (CH3)2COCH3(CH2)3CHCH3CHROH, expecting sandalwood
odor molecules.Actually, the novel compounds possess a wide odor range, different from methoxy elgenol, from typically melon odorants
to derivatives with floral, marine, fruity, faint scent or even metallic aroma. This work describes the methoxylation of methyl heptenone
and Darzens condensation to form 6-methoxy-2,6-dimethyl-heptanol (4), which is an important starting material for synthesizing the
derivatives of 6-methoxy-2,6-dimethyl-heptanol (5), namely 8-methoxy-4,8-dimethylnoman-3-ol (5a), 9-methoxy-5,9-dimethyldecan-4-
ol (5b), 8-methoxy-2,4,8-dimethyl-decan-3-ol (5c), 10-methoxy-6,10-dimethylundecan-5-ol (5d), 9-meth-oxy-2,5,9-trimethyldecan-4-
ol (5e), 10-methoxy-2,6,10-trimethylundecan-5-ol (5f), 1-cyclopentyl-6-methoxy-2,6-dimethyl-heptan-1-ol (5g), 2-methoxy-2,6-
dimethyltridecan-7-ol (5h), 1-cyclohexyl-6-methoxy-2,6-dimethylheptan-1-ol (5i), 9-methoxy-5,9-dimethyldec-1-en-4-ol (5j), pleasant
smell emanating from 10-methoxy-2,6,10-trimethylundecan-5-ol (5f) with elegant melon and delicatesea breeze, 2-methoxy-2,6-
dimethyltridecan-7-ol (5h) with faint scent, fruity and oce-an-like taste and 9-methoxy-5,9-dimethyldec-1-en-4-ol (5j) with melon and
elegant floral.
Keywords: 6-Methoxy-2,6-dimethyl-heptanol derivatives, Novel compounds, Fragrance, Synthesis.
Although 6-methoxy-2,6-dimethyl-heptanol derivatives have
similar structure with methoxy elgenol, structure-activity
relationships of sandalwood odorants do not obtain. On the
contrary, this project affords some new molecules, with a wide
odor range, from typically melon odorants to derivatives with
floral, marine, fruity, faint scent or even metallic aroma.
Typical aroma compounds of melon odorants, 2,6-dimethyl-
5-heptenal and its derivative called 6-methoxy-2,6-dimethyl-
5-heptenal, have applied to various kinds of daily chemical
essence formula8. Hence, the new compounds 5 are synthetized
from 6-methoxy-2,6-dimethyl-5-heptenal (4), obtained by
Darzens glycidic ester condensation of 6-methoxy-6-methyl-
2-heptanone (2), subsequent hydrolysis and decarboxylation
is also presented9. And the compound 2 is prepared from 6-
methylhept-5-en-2-one (1) under the catalysis of concentrated
sulfuric acid10.
INTRODUCTION
Discovering interesting new fragance ingredients in each
family of odorants and being highly innovative in an extre-
mely competitive environment is a real challenge for small
companies today1. Synthetic organic chemistry has provided
perfumers with novel ingredients that are cheaper and more
stable than many natural materials over the years2.
Due to the current scarcity of natural sandalwood
resources, the development of synthetic sandalwood spices
are increasingly active. Molecular modeling studies were
performed to develop a theoretical model of sandalwood odor
compounds in order to explain the ol-factory recognition as
well as to predict, if a new compound might possess sandal-
wood scent3. With the help of such comparisons a model for
sandalwood fragrance molecules was developed4. 7-Methoxy-
3,7-dimethyloctan-2-ol (methoxy elgenol) usually exhibits
sandalwood-type and it was also our initial aim when we synthe-
sized the new derivatives.
EXPERIMENTAL
1H NMR and 13C NMR spectra were recorded on a Bruker
AVANCE III 500 MHz spectrometer with TMS as an internal.
IR spectra were recorded on a Bruker VERTEX 70 spectro-
meter. Reagents and chemicals were purchased from commer-
cial resource and used without further purification.
It is well known that certain prerequisites need to be met
to obtain a sandalwood odor1, such as an optimal distance
between a bulky group and the osmophore group, the most
polar functional group, which, in most cases, bears an O-atom,
which in the sandalwood family most often is a OH function5,6,7
.

Vol. 26, No. 13 (2014)
Synthesis of Novel Fragrant Molecules 6-Methoxy-2,6-dimethyl Heptanol Derivatives 3959
TABLE-1
ODOR DESCRIPTIONS OF 6-METHOXY
Synthesis of 6-methoxy-6-methyl-2-heptanone (2)11: In
a 2L round-bottom flask fitted with a thermometer and a
stirrer is placed 1100 g methanol and 440 g methyl heptenone
(1). Then 65 g of concentrated sulfuric acid is dropped into
the flask over a period of 1 h while stirring at room temperature.
The reaction mixture allows to stand at 50 °C for 22 h. When
the reaction is over, 70.4 g sodium carbonate is added to
neutralize concentrated sulfuric acid. Then methanol is
distilled. The contents of the reaction flask are poured into
500 mL of ice water. After stirring for a while, the organic
layer is separated in a glass separator and the aqueous portion
is extracted with MTBE. The organic extracts are pumped and
the residual oil fractionated in a packed column with an
efficiency of approximately 25 theoretical plates. The yield is
319.3 g (58 %) of 6-methoxy-6-methyl-2- heptanone (2); b.p.
94 °C (14 mm).
-2,6-DIMETHYL-HEPTANOL DERIVATIVES
O
R
OH
Compound
R
Odor description
5a
5b
5c
Ethyl
Rubber odor, slight fruity
Rubber fragrance, ripe melon
Slightly woody (rubber wood),
melon
n-Propyl
i-Propyl
5d
5e
5f
n-Butyl
Squashy melon
2-Methyl-propyl Squashy melon
3-Methyl-butyl
Elegant melon delicate sea breeze,
powerful
5g
5h
5i
Cyclopentyl
n-hexyl
Metallic aroma, faint scent
Faint scent, fruity, marine, powerful
Faint scent, fruity, marine, melon
Melon, elegant floral, powerful
Cyclohexyl
Allyl
Synthesis of sodium methoxide (3): Sodium (90 g) is
placed in a 1 L round-bottom flask, and methyl alcohol is added
to the flask slowly. While sodium disappears, the temperature
is increased to 160 °C and methyl alcohol is removed to get
sodium methoxide powder.
5j
The 6-methoxy-2,6-dimethyl-hetanal in THF are then added
dropwise by a syringe at 0 °C. The reaction mixture is allowed
to warm to room temperature and tracked by GC. Then,
saturated ammonium chloride solution is added to quench the
reaction. The organic layer is poured to a distilling flask. Solvent
is removed and the target compound is purified by silica gel
chromatography. Silica gel is prepared in a column (30 cm
length* 3.5 cm i.d.) and conditioned with a mixed solvent
(100:10, P/E, v/v). Target compound is collected by elution
with a mixed solvent (50:1-100:10, P/E, v/v) and then is
concentrated to 20 mL. After vacuum distillation/transfer
(HVT), solvent is removed under vacuum. An oil like liquid
with an appearance from colourless to yellow was obtained.
The reactions are shown in Table-2.
Synthesis of 6-methoxy-2,6-dimethyl-hetanal (4)12:
Sodium methoxide (15.1g) is added over 2 h to a stirred slurry
of 31.6 g of 6-methoxy-6-methyl-2-heptanone (2) and 30.6 g
ethyl chloroacetate at -10 to -15 °C. The resulting thick slurry
is stirred for an additional 2 h at -10 to -15 °C. The solution of
18 g sodium hydroxide in 150 mL methanol is slowly added
and the resulting solution is heated at 50 °C for 3 h. Methanol
is removed and the reaction mass is then poured into 150 mL
water with stirring. The aqueous reaction mass is extracted
twice with 100 mL MTBE. The MTBE extracts are discarded
and the aqueous layer is acidified (pH 5-6) with concentrated
hydrochloric acid (accompanied by evolution of carbondi-
oxide). The aqueous layer is extracted 3 times, each time with
100 mL MTBE. The organic layer are combined and washed
with 200 mL of water. The MTBE is removed by distillation
at reduced pressure. 0.3 g copper powder is added to the
concentrated organic extract13. Distillation under vacuum
accompanied by release of carbon dioxide affords 6-methoxy-
2,6-dimethyl-hetanal (4); b.p. 95 °C (18 mm).
RESULTS AND DISCUSSION
6-Methoxy-2,6-dimethyl-heptanol
derivatives
[(CH3)2-COCH3(CH2)3CHCH3CHROH] are novel fragrance
compounds, with stable chemical properties, leading us to
interesting new insights into the floral, fruity and melon family.
Especially, R = allyl, the compound emanates pleasant melon
and elegant floral; R = 3-methylbutyl, the compound possesses
elegant melon and delicate sea breeze flavor; R = hexyl, the
compound possesses faint scent, fruity and oceanlike taste.
Reaction mechanism and effect of reaction conditions:
During the course of the methoxylation reaction, which is
mediated by concentrated sulfuric acid catalysts, a H-atom and
a OCH3 group are formally added across the C=C bond of an
alkene (Fig. 1). Boron trifluoride diethyl etherate and sulfonyl
chloride are also employed as catalysts, but the results are not
desired. In addition, temperature plays an important role during
this reaction, which is related with reaction time and productivity.
Table-3 shows the optimum reaction temperature is 50 °C.
6-Methoxy-2,6-dimethyl-heptanol derivatives (5): 6-
methoxy-2,6-dimethyl-hetanal, with a faint floral, slightly
fruity and citrus characteristic aroma, also, fresh herbs taste
and slight melonlike flavor, has been described and used as a
fragrance ingredient for a few years. We find that it can be used
as a raw material and addition reaction with alkyl magnesium
bromide to get alcohols.Astonishingly, the products possessing
interesting ol factory properties (Table-1) which can be applied
in the perfume industry.
General procedure for the synthesis of 6-methoxy-2,6-
dimethyl-heptanol derivatives14: Grignard reagents: In a
round-bottom flask fitted with a thermometer and a stirrer is
placed magnesium, THF and a small amount of bromoalkane
and a grain of iodine. The mixture is heated by hair dryer and
the reaction is induced quickly. Then, bromoalkane in THF is
dropped into the flask. The mixture is kept in an atmosphere
of nitrogen for 2 h with stirring at room temperature.
6-Methoxy-2,6-dimethyl-heptanol derivatives15: Freshly
prepared Grignard reagent (120 % mol) is placed under nitrogen.
TABLE-3
INFLUENCE OF TEMPERATURE ON THE REACTION
Temperature
(°C)
Reaction time
(h)
GC conversion GC purity after
Rate (%)
30.75
86.3
reaction (%)
40
50
60
28
22
21
13.1
64.4
90.2
57.3

3960 Guo et al.
Asian J. Chem.
TABLE-2
SYNTHESIS, GC CONTENT, PURITIES, REACTION TEMPERATURE OF 6-METHOXY-2,6-DIMETHYL-HAPTANOL DERIVATIVES
Grignard reagent from
Product
aGC Content Isomer 1
Isomer 2 (%)
bPurity Isomer
1 Isomer 2 (%)
cReaction
temperature (°C)
61.4
78.5
43.5
6.9
5.6
97.3
1.3
4
4
4
Br
Br
97
1.3
0.2
21.2
98.2
Br
Br
Br
81.2
53.2
16.2
1.3
94.0
95.6
3.5
2.0
3
4
39.2
37.5
14.1
10.6
97.6
96.7
0.8
1.2
6
Br
Br
-40
32.3
20.1
12.8
12.0
92.1
89.6
2.8
8.1
0
Br
Br
-40
86.4
7.6
96.5
3.4
10
Br
aGC Content is based on the addition reaction of 4 with the correspondent Grignard reagents. bPurity is the GC content after purification. c Reaction
temperature is not optimized
O
O
O
O
O
O
O
O
CH3OH
H2SO4
CH3ONa
+
O
Cl
O
2
O
2
1
H
O
O
NaOH
HCl
Fig. 1. Synthesis of 6-methoxy-6-methyl-2-heptanone
O
ONa
O
CH OH
3
-CO2
O
In the process of synthesis of 6-methoxy-2,6-dimethyl-
hetanal 4 (Fig. 2), 2 reacts with ethyl chloroacetate under the
catalysis of sodium methoxide 3, obtaining epoxide carboxylic
acid ester, which undergoes saponification, acidification and
decarboxylation to afford aldehyde 4. Wherein, the strongly
acidic mixture before decarboxylation will give no product.
Therefore, the right amount of sodium hydrogen carbonate is
added to neutralize the system to be acidulous. Except for copper
powder, we attempt N,N-dimethylaniline to be catalyst of
4
Fig. 2. Synthesis of 6-methoxy-2,6-dimethyl heptanol
O
THF
O
RMgBr
+
Mg
+
RBr
O
4
5
H
O
NH4Cl
H2O
R
decarboxylation, but with no improvement16-18
.
R
OMgBr
Present synthesis consisted in preparing the new com-
pounds 5, which are obtained by reaction of 4 with suitable
Grignard reagents (Fig. 3). However, these elegant synthesis
are not so easy to perform. As for bromocyclohexane and
bromo-cyclopentane19,20, whose Grignard reagents don't react
with 4 in the temperature of 0-10 °C, but undergo coupling
OH
Fig. 3. Synthesis of 6-methoxy-2,6-dimethyl heptanol derivatives
reaction. While the temperature reaches to -40 to -80 °C and
the new compounds 5g and 5i can be obtained by addition
reaction. Allyl bromide is another exception. The results are

Vol. 26, No. 13 (2014)
Synthesis of Novel Fragrant Molecules 6-Methoxy-2,6-dimethyl Heptanol Derivatives 3961
differ with the difference of feeding methods21. One way, allyl
bromide and magnesium react for 3 in the THF to give allyl
magnesium bromide, then the mixture are cooled to -10-0 °C
and the compound 4 in THF are dropped over 2 h. We find
that products are complex and the raw material is remaining.
Allyl bromide is so active to generate allylmagnesium in the
mixed solvent, which process coupling reaction easily, resul-
ting in low yield. Another way, 20 % of allyl bromide in THF
is added into the Grignard reagent just initiated to get a handful
of allylmagnesium, then mixture of the remaining allyl
bromide and the compound 4 in the THF are dropped into the
Grignard reagent under the temperature of 10-20 °C over 2 h.
Keeping a little allylmagnesium in the reaction system not
only ensure the process of addition reaction, but also decreases
the probability of side reaction of coupling, obtaining higher
yield of the new compound 5j.
3H); 3.42-3.55 (m, 1H). 13C NMR (CDCl3): major isomers:
75.31/76.24; 74.60; 49.02; 40.14; 38.14/38.79; 35.46/35.26;
33.92; 32.28/32.42; 28.12/31.16; 24.94/24.97; 24.94/24.97;
22.65/22.76; 22.52/22.43; 21.6/21.50; 13.50/15.37.
1-Cyclopentyl-6-methoxy-2,6-dimethylheptan-1-ol
(5g): Purity (96.7 %) was checked by GC-FID. IR: 626w,
743w, 879w, 1074s, 1230s, 1395s, 1453s, 2876w, 2964s,
3471w, 3666s. 1H NMR (CDCl3): 0.84-0.98 (2d, J = 7, 3H);
1.15 (s, 6H); 1.19-2.10 (m, 17H); 3.17 (s, 3H); 3.22-3.31 (m,
1H). 13C NMR (CDCl3): major isomers: 79.18/80.33;74.60;
49.03; 43.93/43.24; 40.14/40.29; 36.40/37.10; 34.94; 29.93/
30.85; 29.17/29.36; 25.52/25.61; 25.43;24.96; 24.94; 21.62/
21.58;12.70/16.86.
2-Methoxy-2,6-dimethyl tridecan-7-ol (5h):Purity (92.1 %)
was checked by GC-FID. IR: 735w, 889w, 1062s, 1242s,
1383s, 1467s, 2898w, 2974s, 3667s. 1H NMR (CDCl3): 0.89-
0.95 (m, 6H); 1.15 (s, 6H); 1.20-1.72 (m, 18H); 3.18 (s, 3H);
3.40-3.60 (m, 1H). 13C NMR (CDCl3): major isomers: 75.03/
76.00; 74.60/74.48; 49.05; 40.15/40.00; 38.21/38.83; 34.52;
33.89/33.49; 31.84/32.39; 29.39/29.67; 26.24/26.05; 24.95/
24.87; 24.95/24.84; 22.61; 21.63/21.52; 14.04; 13.56. minor
isomer: 40.48; 39.38; 36.73; 36.64; 19.48; 18.47; 15.34.
1-Cyclohexyl-6-methoxy-2,6-dimethylheptan-1-ol (5i):
purity (89.6 %) was checked by GC-FID. IR: 723w, 889w,
1064s, 1240s, 1414s, 2896w, 2974s, 3676s. 1H NMR (CDCl3):
0.80-0.93 (2d, J = 6.5, 3H); 0.9-1.15 (m, 2H); 1.13 (s, 6H);
1.19-2.10 (m, 17H); 3.17 (s, 3H); 3.05-3.16 (m, 1H). 13C NMR
(CDCl3): major isomers: 78.94/80.62; 74.62; 49.04; 40.74/
40.27; 40.14/40.21; 34.75/35.02; 34.72/31.33; 29.43/30.15;
29.14/27.24; 26.48/26.54; 26.24/26.19; 26.04; 24.96; 24.92;
21.51/21.36; 12.84/16.51.
8-Methoxy-4,8-dimethylnoman-3-ol (5a): Purity (97.3
%) was checked by GC-FID. IR: 735w, 889w, 1082s, 1242s,
1383s, 1467s, 2904w, 2969s, 3668s. 1H NMR (CDCl3): 0.86
(2d, J = 6.5,11.5, 3H); 0.93 (t, J = 6.5, 3H); 1.12 (s, 6H); 1.15-
1.20 (m, 9H); 1.76 (s, 1H); 3.15 (s, 3H); 3.25-3.5 (m, 1H). 13C
NMR (CDCl3): major isomers: 76.49; 74.60; 48.99; 40.13;
37.79/38.51; 33.90/32.37; 27.24/26.28; 24.95; 24.95; 21.59/
21.46; 13.41/15.38; 10.64/10.32.
9-Methoxy-5,9-dimethyldecan-4-ol (5b): Purity (97 %)
was checked by GC-FID. IR: 888w, 1064s, 1230s, 1404s,
2895w, 2973s, 3675s. 1H NMR (CDCl3): 0.87-0.9 (2d, J = 7,
12.5, 3H); 0.94 (t, J = 7, 3H); 1.14 (s, 6H); 1.2-1.60 (m, 12H);
3.18 (s,3H); 3.40-3.55 (m,1H). 13C NMR (CDCl3): major
isomers: 74.49/75.69; 74.59; 49.03; 40.17; 38.21/38.86; 36.70/
35.68; 33.86/32.40; 24.97; 24.97; 21.63/21.51; 19.42/19.23;
14.11/15.31; 13.57.
9-Methoxy-5,9-dimethyl dec-1-en-4-ol (5j): Purity (96.5
%) was checked by GC-FID. IR: 635w, 743w, 889w, 918s,
1094s, 1250s, 1395s, 1454s, 1649s, 2906w, 2993s, 3461s,
8-Methoxy-2,4-dimethyldecan-3-ol (5c): Purity (98.2 %)
was checked by GC-FID. IR: 879w, 1064s, 1239s, 1375s,
1463s, 2925w, 2973s, 3666s. 1H NMR (CDCl3): 0.75-1.0 (m,
10H); 1.12 (s, 6H); 1.15-1.85 (m, 9H); 3.00-3.10 (m, 1H);
3.15 (s,3 H). 13C NMR (CDCl3): major isomers: 79.99/81.03;
74.57; 48.99; 40.15; 35.00/35.83; 34.73/31.69; 30.93/30.93;
24.93; 24.90; 21.43/21.30; 19.39/20.00; 18.56; 12.96/16.35.
10-methoxy-6,10-dimethylundecan-5-ol (5d): Purity
(94.0 %) was checked by GC-FID. IR: 645w, 723w, 869w,
1054s, 1230s, 1385s, 1463s, 2896w, 2984s, 3676s. 1H NMR
(CDCl3): 0.82-0.89 (d, J = 7, 3H); 0.89-0.94 (t, J = 7, 3H);
1.15 (s, 6H); 1.18-1.73 (m, 15H); 3.15 (s, 3H); 3.35-3.55 (m,
1H). 13C NMR (CDCl3): major isomers: 75.03/75.94; 74.59;
49.01; 40.15; 38.20/38.83; 34.18/33.15; 33.88/32.39; 28.47/
28.28; 24.93; 24.93; 22.76; 21.62/21.50; 14.02/15.32; 13.54.
9-Methoxy-2,5,9-trimethyldecan-4-ol(5e): Purity (95.6
%) was checked by GC-FID. IR: 635w, 733w, 889w, 1074s,
1240s, 1405s, 1463s, 2896w, 2974s, 3675s. 1H NMR (CDCl3):
0.85-0.97 (m, 9H); 1.15 (s, 6H); 1.23-1.85 (m, 12H); 3.15 (s,
3H); 3.45-3.65 (m, 1H). 13C NMR (CDCl3): major isomers:
74.60/73.68; 72.90; 48.99; 43.66/42.49; 40.14/; 38.64/39.92;
33.80/32.44; 24.93/24.96; 24.93/24.90; 24.80/24.69; 23.60/
23.88; 21.98/21.69; 21.61/21.52; 13.62/15.17.
1
3676s. H NMR (CDCl3): 0.85-0.95 (m, 3H); 1.14 (s, 6H);
1.21-2.39 (m, 10H); 3.15 (s, 3H); 3.40-3.60 (m, 1H); 5.10 (m,
2H); 5.85 (m, 1H). 13C NMR (CDCl3): major isomers: 135.59;
117.58; 74.57/74.49; 73.04; 49.01; 40.14/39.12; 38.29/37.85;
33.70/32.64; 24.95/24.97; 24.91; 24.91;21.55/21.39; 13.83/
15.22.
Conclusion
We have synthesized novel fragrant molecules 6-methoxy-
2,6-dimethylheptanol derivatives. These compounds are first
synthesized, possessing a wide odor range, from typically
melon odorants to derivatives with floral, marine, fruity, faint
scent or even metallic aroma. It provides a series of new flavors
for spices industry and have the potential to be applied to the
Daily Chemical Essence Industry.
ACKNOWLEDGEMENTS
The authors thank Qingsheng Guo for the 1H NMR and C
NMR structure. Thanks are also due to Suning Zhang for IR
interpretation.
REFERENCES
1. P. Kraft, J.A. Bajgrowicz, C. Denis and G. Fráter, Angew. Chem. Int. Ed.,
39, 2980 (2000).
10-Methoxy-2,6,10-trimethylundecan-5-ol(5f): Purity
(97.6 %) was checked by GC-FID. IR: 869w, 1064s, 1240s,
1404s, 2896w, 2984s, 3686s. 1H NMR (CDCl3): 0.84-0.92 (m,
9H); 1.13 (s, 6H); 1.15-1.58 (m, 13H); 1.65 (s, 1H); 3.18 (s,
2. A.-D. Fortineau, J. Chem. Educ., 81, 45 (2004).
3. G. Buchbauer, F. Zcchmeister-Machhart, P. Weiß-Greilar and P.
Wolschann, Arch. Pharm. Pharm. Med. Chem., 330, 112 (1997).

3962 Guo et al.
Asian J. Chem.
4. G. Buchbauer, A. Hillisch, K. Mraz and P. Wolschann, Helv. Chim.
Acta, 77, 2286 (1994).
14. S. Tartaglia, F. Pace, P. Scafato and C. Rosini, Org. Lett., 10, 3421
(2008).
5. D.I. Hadaruga, N.G. Hadaruga and S. Muresan, Chem. Bull. Politehnica
Univ., 52, 1 (2007).
15. P. Anbarasan, Ph.D. Thesis, Enantioselective Synthesis of Bio-Active
Bicyclic Acetals, Cyclic Ethers and Lactones, Indian Institute of Science,
Bangalore, India (2007).
6. T. Hasegawa, H. Izumi,Y. Tajima and H.Yamada, Molecules, 17, 11292
(2012).
7. C. Plessis, Biodiversity, 5, 1083 (2008).
16. J.A. Waters and B. Witkop, J. Org. Chem., 36, 3232 (1971).
17. S.P. Singh and J. Kagan, J. Org. Chem., 35, 2203 (1970).
18. N.K. Nelson and H.H. Morris, J. Am. Chem. Soc., 75, 3337 (1953).
19. J. Clayden, M. Pickworth and L.H. Jones, Chem. Commun., 5, 547
(2009).
8. H. Mao, Domestic-Overseas Flavor Fragrance Cosmetic Inform., 2,
16 (2003).
9. J. P. Munch, Acta Chem. Scand., 7, 1041 (1953).
10. J.D. Surmatis and A. Ofner, J. Org. Chem., 28, 2735 (1963).
11. J.D. Surmatis and C. West, US Patent 3156714 (1964).
12. M.A. Sprecker, R.W. Trenkle, B.D. Mookherjee, M.H. Vock, J.F. Vinals,
J. Kiwala and F.L. Schmitt, US Patent 4,281,177 (1981).
13. S.J. William, J.S. Belew, L.J. Chinn and R.H. Hunt, J. Am. Chem. Soc.,
75, 4995 (1953).
20. A.R. Hudson, S.L. Roach, R.I. Higuchi, D.P. Phillips, R.P. Bissonnette,
W.W. Lamph, J. Yen, Y. Li, M.E. Adams, L.J. Valdez, A. Vassar, C.
Cuervo, E.A. Kallel, C.J. Gharbaoui, D.E. Mais, J.N. Miner, K.B.
Marschke, D. Rungta, A. Negro-Vilar and L. Zhi, J. Med. Chem., 50,
4699 (2007).
21. M. Chen, C. Xu and X. Zhu, J. Jiangsu Polytech. Univ., 21, 8 (2009).