Silicomolybdic acid supported on silica gel: An efficient catalyst for Hosomi-Sakurai reactions

Article abstract of DOI:10.1016/j.tet.2011.05.093

Silicomolybdic acid that is supported on silica gel (50 wt %) efficiently catalyzes the high-yielding Hosomi-Sakurai allylation of carbonyl compounds by allyltrimethylsilane in the presence of benzyl alcohol. The reaction rates of inactive substrates and the yields were greatly increased when preformed acetals were used as substrates.

Full text of DOI:10.1016/j.tet.2011.05.093

Tetrahedron 67 (2011) 5621e5629
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Silicomolybdic acid supported on silica gel: an efficient catalyst
for HosomieSakurai reactions
*
Kaliyappan Murugan, Sankareswaran Srimurugan, Chinpiao Chen
Department of Chemistry, National Dong Hwa University, Soufeng, Hualien 974, Taiwan, ROC
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 23 April 2011
Received in revised form 22 May 2011
Accepted 23 May 2011
Available online 30 May 2011
Silicomolybdic acid that is supported on silica gel (50 wt %) efficiently catalyzes the high-yielding
HosomieSakurai allylation of carbonyl compounds by allyltrimethylsilane in the presence of benzyl
alcohol. The reaction rates of inactive substrates and the yields were greatly increased when preformed
acetals were used as substrates.
Ó 2011 Elsevier Ltd. All rights reserved.
Keywords:
Silicomolybdic acid (SMA)
HosomieSakurai reaction
Brønsted acids
Allylation
Homoallylic ether
1. Introduction
are reportedly excellent catalysts of the synthesis of acetals, thio-
acetals, and acylals from carbonyl compounds.48
The HosomieSakurai allylation of carbonyl compounds and ac-
etals by allyltrimethylsilane to form homoallyl alcohols or ethers is
an extensively explored carbonecarbon bond-forming reaction.1ꢀ6
The reaction is usually promoted using a stoichiometric or catalytic
amount of Lewis acid,7ꢀ29 Brønsted acid30ꢀ40 or other material.3,41
The direct allylation of carbonyl compounds using allyl-
trimethylsilane has limited applicability, because it involves high
catalyst loadings, low yields, and long reaction times. However, the
acetals of the corresponding carbonyl compounds greatly increase
reaction rates and yields. The use of Brønsted acids in this con-
version has been less studied than has the use of Lewis acids. In fact,
sulfonamide37,40 and sulfonic acid-bearing electron-withdrawing
substituents38,39 are the only classes of Brønsted acid catalysts that
have been used. Other readily available sulfonic acids, such as
p-TsOH and camphorsulfonic acid, have been shown to be less ac-
tive as catalysts of the allylation reaction. The authors’ continued
interest in the asymmetric allylation of carbonyl compounds42 and
the replacement of conventional Brønsted acid and Lewis acid
catalysts with more selective, highly acidic, and greener solid acid
catalysts for various functional group transformations43 have led us
to study the use of heteropoly acids44ꢀ47 as catalysts for the
HosomieSakurai allylation (Scheme 1). Various heteropoly acids
HPA-SiO2 (cat.)
TMS
O
(3.0 eq)
R
R1
BnOH (2.0 eq)
CH3CN, 5 min - 6 h
Carbonyl
compounds
XO
R
R1
R = Alkyl / Aryl
R1 = Alkyl / Aryl/H
X = Alkyl / Acyl
XO
R
OX
R1
HPA-SiO2 (cat)
TMS
Acetals /
Acylals
(1.5 eq)
CH3CN, < 30 min
Scheme 1. HosomieSakurai reaction of carbonyl compounds, acetals, and acylals with
allyltrimethylsilane.
2. Results and discussion
The feasibility of the allylation was initially explored using
benzaldehyde 1 (Table 1) as a model substrate and various heter-
opoly acids as catalysts. Initial attempts at the direct allylation of 1
to homoallyl alcohol by allyltrimethylsilane were either
* Corresponding author. Tel.: þ886 3 863 3597; fax: þ886 3 863 0475; e-mail
address: chinpiao@mail.ndhu.edu.tw (C. Chen).
0040-4020/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2011.05.093

5622
K. Murugan et al. / Tetrahedron 67 (2011) 5621e5629
Table 1
inefficient, and so more expensive benzyl trimethylsilyl ether was
used.20,39 The commonly used phosphomolybdic acid (PMA) gave
the desired product 1a in 75% yield at a catalyst loading of 5 mol %
(Table 1, entry 1). The reaction did not proceed to completion, but
halted after 30 min no product was formed after a reaction time of
2 h. Complete conversion required a minimum of 3.0 equiv of
allyltrimethylsilane, and attempts to reduce the number of equiv-
alents resulted in partial conversions and lower yields.
Optimization of reaction conditions for HosomieSakurai allylation of benzaldehyde
catalyzed by heteropoly acids
OBn
HPA, solvent
BnOH
CHO
TMS
+
1
1a
Entry HPAa
x (mol %) Solvent T (ꢁC) t (h) Yieldb (%)
The more acidic phosphotungstic acid (PWA) yielded more
product in a shorter reaction time. Similarly complete conversion
was achieved using silicotungstic acid (SWA) after 2 h, the products
obtained using both catalysts contained an impurity (Table 1, en-
tries 2 and 3). Surprisingly, less silicomolybdic acid (SMA) was
a more effective, forming homoallyl ether 1a quantitatively in
15 min (Table 1, entry 4). The catalyst retained similar reactivity at
a lower loading of 2 mol %, below which the reaction proceeded
more slowly. Heating the reaction mixture to 40 ꢁC reduced the
yield, probably because of competitive hydrolysis of the acetal back
to aldehyde (Table 1, entry 8). A more active and selective form of
SMA catalyst, supported on silica gel, was prepared and screened
for effectiveness in the allylation reaction. The loading of bulk
supported catalyst (2 mol %) that was made from 10 to 50 wt % SMA
on silica gel was investigated. The activity of the supported catalyst
increased with the surface loading of the silica gel with SMA, and
50 wt % loading was found to be optimal (Table 1, entries 9e14).
Reactions that were performed at higher temperature by reducing
the catalyst loading or the surface loading again proceeded more
slowly, owing to the hydrolysis of acetal. Dichloromethane and
toluene afforded good yields that were exceeded only by those
achieved when the reaction solvent was acetonitrile (Table 1, en-
tries 15e18). The catalyst was recycled up to three times although
each run considerably reduced catalytic activity (Table 1, entries
19e21).
1
2
3
4
5
6
7
8
PMA
PWA
SWA
SMA
SMA
SMA
SMA
SMA
5.0
5.0
5.0
5.0
3.0
2.0
1.0
1.0
2.0
2.0
2.0
1.0
2.0
2.0
2.0
2.0
2.0
2.0
2.0
CH3CN rt
CH3CN rt
CH3CN rt
CH3CN rt
CH3CN rt
CH3CN rt
CH3CN rt
CH3CN 40
CH3CN rt
CH3CN rt
CH3CN rt
CH3CN 40
CH3CN rt
CH3CN rt
2.0
0.25 92
2.0 85
0.25 99
0.25 97
0.25 97
75
2.0
2.0
2.0
1.5
0.5
3.0
0.5
86
70
90
93
95
85
95
9
SMA/SiO2 (10 wt %)
SMA/SiO2 (20 wt %)
SMA/SiO2 (30 wt %)
SMA/SiO2 (30 wt %)
SMA/SiO2 (40 wt %)
SMA/SiO2 (50 wt %)
SMA/SiO2 (50 wt %)
SMA/SiO2 (50 wt %)
SMA/SiO2 (50 wt %)
SMA/SiO2 (50 wt %)
SMA/SiO2 (first cycle)
10
11
12
13
14
15
16
17
18
19
20
21
0.08 99
THF
CH2Cl2
rt
rt
2.0
2.0
2.0
2.0
5
68
73
d
Toluene rt
DMF rt
CH3CN rt
CH3CN rt
CH3CN rt
0.08 99
SMA/SiO2 (second cycle) 2.0
SMA/SiO2 (third cycle) 2.0
1.0
3.0
90
85
a
HPA: PMA-Phosphomolybdic acid; PWA-Phosphotungstic acid; SMA-
Silicomolybdic acid; SWA-Silicotungstic acid.
b
Isolated yields.
unsuccessful or afforded only traces of the product under various
reaction conditions. An alternative protocol for acetal formation
prior to allylation was therefore attempted by reacting benzalde-
hyde, allylsilane, and benzyl alcohol in the presence of heteropoly
acids. Many of the reported catalyst systems failed or were
Substituted aromatic aldehydes, such as 4-methylbenzaldehyde
2 and 4-tert-butylbenzaldehyde 3 gave the homoallyl ethers 2a and
3a in high yields under the optimal conditions (Table 2, entries
Table 2
a
HosomieSakurai allylation of carbonyl compounds catalyzed by SMA/SiO2
Entry
1
Substrate
t (h)
Product
Yieldb (%)
95
2
0.5
2a
R = Me
R = Me
OBn
R
CHO
R
R = t-Bu
R = t-Bu
2
3
3
4
1.0
3a
4a
82
92
o-isomer
p-isomer
m-isomer
o-isomer
p-isomer
m-isomer
0.75
OBn
CHO
CHO
4
5
5
6
0.75
0.5
5a
6a
99
98
Cl
Cl
MeO
6
7
7
8
1.0
6.0
7a
8a
40c
61
MeO
CHO
o-isomer
p-isomer
m-isomer
o-isomer
p-isomer
m-isomer
OBn
8
9
9
10
3.0
3.0
9a
10a
57
50
NO2
NC
NO2
NC
OBn
10
11
11
12
1.5
11a
12a
80
70
CHO
CHO
OBn
0.16
TBSO
TBSO

K. Murugan et al. / Tetrahedron 67 (2011) 5621e5629
5623
Table 2 (continued )
Entry
Substrate
CHO
t (h)
Product
Yieldb (%)
OBn
12
13
13
14
0.75
1.0
13a
14a
95
82
BnO
CHO
OBn
S
S
14
15
15
16
2.0
1.0
15a
16a
30
90
CHO
OBn
OBn
S
S
CHO
CHO
16
17
1.0
17a
82
78
OBn
17
18
18
19
3.0
1.0
18a
19a
CHO
CHO
OBn
40
(dr 3:2)
OBn
CHO
19
20
2.0
20a
61
OBn
OBn
20
21
21
22
3.0
2.0
21a
22a
50
80
CHO
CHO
OBn
22
23
23
24
1.5
0.5
23a
25a
92
85
CHO
CHO
O
O
OBn
OBn
24
25
26
25
26
27
0.16
1.0
25a
26a
27a
60
55
50
O
OBn
O
OBn
O
2.0
(continued on next page)

5624
K. Murugan et al. / Tetrahedron 67 (2011) 5621e5629
Table 2 (continued )
Entry
Substrate
t (h)
Product
Yieldb (%)
60
O
OBn
27
28
28
29
2.0
28a
29a
O
OBn
2.0
60
OBn
O
O
29
30
31
2.0
30a
31a
51
90
OBn
30
0.25
a
Catalyst loading (2.0 mol %) and 3.0 equiv allyltrimethylsilane, 2.0 equiv benzyl alcohol.
Isolated yields.
No homoallyl ether was observed.
b
c
1 and 2). The position of the substituents on the aryl ring did not
affect the yield of the reaction, as observed when isomeric chlor-
obenzaldehydes 4e6 were used (Table 2, entries 3e5). p-Ani-
saldehyde 7, with an electron-releasing methoxy group, reacted
slowly to form the corresponding diallyl compound 7a in 40%
yield without any trace of the expected homoallyl ether (Table 2,
entry 6). In contrast, the electron-withdrawing nitro group on the
benzaldehyde 8e10 gave homoallyl ethers in moderate yields,
irrespective of the position of the functional group (Table 2,
entries 7e9).
4-Cyanobenzaldehyde 11 formed the desired allylated product
11a in good yield without any other product, because the nitrile
groups underwent side reactions (hydrolysis and the Ritter re-
action)49 (Table 2, entry 10). The extreme stability of the TBS group
under catalytic conditions resulted in a high yield of silylated
homoallyl ether 12a in a short reaction time. Polycyclic aromatic
aldehydes, such as naphthaldehyde 13 and anthracenecarbox-
aldehyde 14, reacted similarly to benzaldehyde (Table 2, entries 12
and 13), whereas heteroaromatic aldehydes reacted differently,
depending on the position of the carbonyl group. Unreacted start-
ing material thiophene-2-carboxaldehyde 15 was obtained along
with the product (30%), but the reaction ran to completion when
the corresponding 3-isomer 16 was instead (Table 2, entries 14
and 15). Cinnamaldehyde 17 underwent allylation selectively at the
1,2 position, forming the homoallyl ether in 82% yield.
The efficiency of the allylation of aliphatic and alicyclic alde-
hydes with SMA/SiO2 was similar to that with aromatic aldehydes.
The yields were a little lower in the former systems because in-
complete conversions yielded homoallyl ethers as the only product,
without any impurity. Monocyclic cyclohexanecarboxaldehyde 18
afforded higher yields than the chiral bicyclic myrtenal 19, which
reacted at the 1,2 position across the conjugated enone with a weak
diastereoselectivity (3:2). Aliphatic aldehydes 20e23 exhibited
similar tendencies to undergo allylation under the optimal condi-
tions, affording homoallyl ethers in 50e92% yield.
The stability of the acetonide group was examined using Garner
aldehyde 24 as the substrate. A rapid reaction occurred but no
desired product was obtained. Allylation occurred at the acetonide
moiety, unlike at the aldehyde group, forming 25a in 85% yield. The
rapid formation of 25a motivated the screening of acetone and
other ketones for allylation under the optimal reaction conditions.
Homoallyl ethers were obtained in a moderate to good yield in
a short reaction time using various aliphatic ketones 25e30 (Table
2, entries 24e29). A variety of aromatic ketones (substituted ace-
tophenones, benzophenones, and acetonaphthone) and hetero-
aromatic ketones reacted very slowly with 5e10% conversion under
variously modified experimental conditions. Cyclohexanone 31
reacted similarly to aliphatic ketones with a 90% yield of allylated
ether 31a within 15 min.
Preformed ketals of unreactive ketones underwent allylation in
a very short time. The amount of allylsilane that was used with
these substrates was reduced greatly (1.5 equiv) without any drop
in yield of the product (Table 3). The reaction was quantitative yield
in the case of cyclohexanone dimethyl acetal 32 but a slight loss of
yield was observed when acetophenone dimethyl acetal 33 was
used. Similarly slow-reacting aldehydes afforded the product in
quantitative yield in a very short reaction time with the preformed
acetals, as demonstrated using anisaldehyde dimethyl acetal 34 and
2-phenylpropanal dimethyl acetal 35. The reaction of anisaldehyde
dimethyl acetal 34 formed a considerable amount of diallylated
product 7a under the typical conditions, as observed using free
aldehyde 7. Compound 7a was obtained perhaps because the de-
sired product 34a was converted to an intermediate (40) and then
reacted with allyltrimethylsilane to yield the product (7a) that was
ultimately obtained (Scheme 2). However, reducing the number of
equivalents of allylsilane to 1.0 equiv inhibited the formation of
diallyl product 7a, affording the desired homoallyl ether 34a in 92%
yield. Cyclic acetals 36 and 37 were shown to be useful substrates in
the transformation, forming homoallyl ethers 36a and 37a in
moderate yields in a very short reaction time. This result represents
the first example of the ring-opening allylation of cyclic acetal
under truly catalytic and ambient conditions.50 Further reaction of
the initially formed desired product (36a and 37a) under the typical
experimental conditions produced symmetric ether in near-
quantitative yield in less than 10 min from 36 and 37.50 Many
modifications were made in attempts to freeze the reaction at the
desired product and resulted in reducing the loading of the mild
catalyst (10 wt % SMA on silica) as a suitable reagent system. To
facilitate further manipulation of the homoallyl product, the ether
functional group of the substrate was replaced with ester moieties.
Acylals 38 and 39 were used to investigate the feasibility of the
reaction. Homoallyl esters 38a and 39a were successfully isolated
from both of these substrates in 30e40% yield and the hydrolysis of
acylal was found to be the dominating reaction. Optimization studies
demonstrated that replacing acetonitrile with dichloromethane as the
solvent suppressed the hydrolysis and improved the yields to over 80%.

K. Murugan et al. / Tetrahedron 67 (2011) 5621e5629
5625
Table 3
HosomieSakurai allylation of ketals, acetals, and acylals catalyzed by SMA/SiO2
a
Entry
Substrate
t (h)
Product
Yieldb (%)
OMe
OMe
1
32
33
0.16
32a
33a
99
82
OMe
OMe
OMe
OMe
2
3
0.16
0.16
OMe
MeO
MeO
OMe
OMe
34a:7a
92:5c
34a
7a
34
MeO
(74:19)d
97
(dr 1:2.5)
4
5
6
7
35
36
37
0.16
0.32e
0.5e
35a
36a
37a
OMe
MeO
Br
MeO
OH
O
5550
O
O
Br
OH
O
O
4550
O
OAc
OAc
OAc
38
39
0.16
0.25
38a
39a
85f
80f
OAc
OAc
8
Cl
Cl
OAc
a
Catalyst loading (2.0 mol %) and 1.5 equiv allyltrimethylsilane.
Isolated yields.
b
c
d
e
f
Allyltrimethylsilane (1.0 equiv).
Allyltrimethylsilane (1.5 equiv).
SMA/SiO2 (10 wt %) and 0.5 mol % catalyst loading.
Solvent: DCM and 0.5 mol % catalyst loading.
acylals in moderate to high yields in a short reaction time. This
method represents the first example of the direct allylation of al-
dehydes and ketones in the presence of cheap and readily available
benzyl alcohols. The difference between the reactivities of pro-
tected and free carbonyl compounds may be able to be exploited in
the selective allylation of multi carbonyl compounds even higher
yields.
H+
BnO
H+
TMS
+OMe
OMe
4. Experimental section
OMe
7a
34a
40
4.1. Activation of silicomolybdic acid
Scheme 2. The proposed mechanism of formation of 7a.
Silicomolybdic acid hydrate (20%) was purchased from Aldrich
(Milwaukee, WI, USA). SMA was placed in a single neck round-
bottom flask, which was heated to 110 ꢁC under reduced pressure
for 6 h, yielding a fine yellow solid, which was used in a Hoso-
mieSakurai reaction.
3. Conclusion
In summary, SMA that is supported on silica gel efficiently cat-
alyzes the allylation of carbonyl compounds, acetals, ketals, and

5626
K. Murugan et al. / Tetrahedron 67 (2011) 5621e5629
4.2. Preparation of SMA/SiO2 (50% w/w) catalyst
To a solution of H4SiO4Mo12 36$xH2O (500 mg, 0.5 equiv by wt)
5.01e5.06 (m, 2H), 4.46 (d, 1H, J¼11.8 Hz), 4.34e4.37 (m, 1H), 4.28 (d,
1H, J¼11.8 Hz), 2.58e2.64 (m, 1H), 2.39e2.46 (m, 1H); 13C NMR
O
(100.6 MHz, CDCl3) d: 140.4, 138.2, 134.3, 133.3, 128.6, 128.3, 128.2,
in MeOH (5 mL) was slowly added silica gel (500 mg, 0.5 equiv by
wt, 70e230 mesh). The mixture was stirred at room temperature
for 6 h. The evaporation of MeOH under reduced pressure gave
a dry yellowish powder, which contained 50% w/w of SMA.
127.6, 127.5, 117.2, 80.4, 70.5, 42.5; IR n: 3066, 2903, 2861, 1901, 1641,
1597, 1492, 1454, 1342, 1296, 1205, 1088, 1014, 916, 827, 735 cmꢀ1; EI-
MS m/z: 233 (4), 231 (12), 139 (3), 91 (100) 65 (5); HRMS-EI (m/z):
[M]þ calcd for C17H17ClO, 272.0968; found, 272.0961.
4.3. Allylation of carbonyl compounds
4.3.6. Compound 6a.1-(1-(Benzyloxy)but-3-enyl)-3-chlorobenzene. 1H
NMR (400 MHz, CDCl3) d: 7.21e7.35 (m, 9H), 5.73e5.82 (m, 1H),
To a solution of benzaldehyde 1 (100 mg, 0.942 mmol) in aceto-
nitrile (2 mL) wasadded 50wt % SMA/SiO2 (68 mg, 0.018 mmol). Then
5.03e5.08 (m, 2H), 4.49 (d,1H, J¼11.8 Hz), 4.34e4.37 (m, 1H), 4.30 (d,
1H, J¼11.8 Hz), 2.59e2.64 (m, 1H), 2.40e2.45 (m, 1H); 13C NMR
benzyl alcohol (195
mL, 1.88 mmol) and allyltrimethylsilane
(100.6 MHz, CDCl3) d: 144.2, 138.2, 134.4, 134.3, 129.7, 128.3,
(0.449mL,2.82mmol)wereaddeddropwiseatambienttemperature.
The reactants were stirred for a further 5 min. After the completion of
reaction (TLC), brine (10 mL) was added and the reaction mixture was
extracted with ether (2ꢂ10 mL). The combined ether layer was dried
over MgSO4, filtered, and concentrated under reduced pressure. Pu-
rification of the crude product by column chromatography afforded
pure homoallylic benzyl ether 1a as a colorless oil (222 mg, 99%).
127.8127.7, 127.6, 126.9, 125.0, 117.3, 80.6, 70.6, 42.5; IR n: 3066, 3030,
2863, 1948, 1872, 1641, 1596, 1575, 1430, 1391, 1341, 1195, 1096, 1074,
997, 916, 787, 735, 699 cmꢀ1; EI-MS m/z: 233 (4), 231 (13), 139 (3), 91
(100), 77 (2), 65 (5); HRMS-EI (m/z): [M]þ calcd for C17H17ClO,
272.0968; found, 272.0964.
4.3.7. Compound 7a. 1-(Hepta-1,6-dien-4-yl)-4-methoxybenzene. 1H
NMR (400 MHz, CDCl3)
5.62e5.73 (m, 2H), 4.93e5.00 (m, 4H), 3.79 (s, 3H), 2.55e2.76 (m,1H),
2.29e2.44 (m, 4H); 13C NMR (100.6 MHz, CDCl3)
: 157.8, 136.9, 136.7,
: 3075, 2911, 2835, 1830, 1742,
d
: 7.08 (d, 2H, J¼8.5 Hz), 6.85 (d, 2H, J¼8.6 Hz),
4.3.1. Compound 1a. 1-((1-Phenylbut-3-enyloxy)methyl)benzene. 1H
NMR (400 MHz, CDCl3)
d: 7.28e7.38 (m, 10H), 5.75e5.85 (m, 1H),
d
5.01e5.07 (m, 2H), 4.48 (d, 1H, J¼11.8 Hz), 4.36e4.39 (m, 1H), 4.28
128.5, 115.9, 113.6, 55.1, 44.7, 40.5; IR n
(d, 1H, J¼11.8 Hz), 2.61e2.68 (m, 1H), 2.41e2.48 (m, 1H); 13C NMR
1639, 1611, 1508, 1441, 1301, 1248, 1177, 1038, 912, 827 cmꢀ1; EI-MS m/
z: 202 (Mþ, 5), 162 (11), 161 (100), 129 (8), 121 (6), 91 (11), 77 (4);
HRMS-EI (m/z): [M]þ calcd for C14H18O, 202.1358; found, 202.1362.
(100.6 MHz, CDCl3) d: 141.8, 138.5, 134.9, 128.4, 128.3, 127.7, 127.4,
126.9, 116.8, 81.1, 70.3, 42.6; IR n: 3064, 2862,1950,1810,1640,1494,
1454, 1354, 1203, 1091, 914, 735 cmꢀ1; EI-MS m/z: 237 (Mþ, 1), 197
(18), 129 (6), 115 (4), 91 (100), 77 (5); HRMS-EI (m/z): [M]þ calcd for
C17H18O, 238.1358; found, 238.1352.
4.3.8. Compound 8a. 1-(1-(Benzyloxy)but-3-enyl)-2-nitrobenzene. 1H
NMR (400 MHz, CDCl3)
d
: 7.93 (d,1H, J¼8.1 Hz), 7.84 (d, 1H, J¼7.8 Hz),
7.65 (t, 1H, J¼7.5 Hz), 7.41e7.45 (m, 1H), 7.28e7.35 (m, 5H), 5.89e5.96
4.3.2. Compound 2a. 1-(1-(Benzyloxy)but-3-enyl)-4-methylbenzene.
(m, 1H), 5.07e5.12 (m, 2H), 4.42 (d, 1H, J¼11.6 Hz), 4.34 (d, 1H,
1H NMR (400 MHz, CDCl3)
d: 7.25e7.7.37 (m, 7H), 7.20 (d, 2H,
J¼11.6 Hz), 2.56e2.61 (m, 2H); 13C NMR (100.6 MHz, CDCl3)
d: 148.8,
J¼8 Hz), 5.78e5.85 (m, 1H), 5.02e5.09 (m, 2H), 4.48e4.51 (d, 1H,
138.0, 137.8, 134.1, 133.3, 128.4, 128.3, 128.1, 127.7, 127.7, 124.2, 117.5,
J¼11.9 Hz), 4.34e4.38 (m, 1H), 4.28 (d, 1H, J¼11.9 Hz), 2.62e2.69 (m,
76.4, 71.5, 42.0; IR n: 3073, 2923, 2863, 1951, 1835, 1641, 1524, 1395,
1H), 2.42e2.49 (m, 1H), 2.39 (s, 3H); 13C NMR (100.6 MHz, CDCl3)
d:
1353, 1298, 1092, 1027, 917, 856, 745 cmꢀ1; EI-MS m/z: 242 (8), 128
(1), 91 (100), 77 (3), 65 (6); HRMS-EI (m/z): [M]þ calcd for C17H17NO3,
283.1208; found, 283.1202.
138.8, 138.6, 137.3, 135.0, 129.1, 128.3, 127.7, 127.4, 126.8, 116.7, 81.0,
70.2, 42.6, 21.1; IR n: 3028, 2923, 2861, 1948, 1904, 1806, 1640, 1513,
1454, 1347, 1305, 1204, 1091, 914, 816, 734, 697 cmꢀ1; FABMS m/z:
253 (Mþþ1, 5), 237 (41), 237 (2), 213 (68),167 (10),147 (99),121 (45),
107 (70), 93 (100); HRMS-FAB (m/z): [M]þ calcd for C18H20O,
252.1514; found, 253.1583.
4.3.9. Compound 9a. 1-(1-(Benzyloxy)but-3-enyl)-4-nitrobenzene. 1H
NMR (400 MHz, CDCl3)
d
: 8.22 (d, 2H, J¼8.6 Hz), 7.50 (d, 2H, J¼8.4 Hz),
7.29e7.36 (m, 5H), 5.71e5.81 (m, 1H), 5.00e5.06 (m, 2H), 4.36e4.52
(m, 2H), 4.34 (d,1H, J¼11.8 Hz), 2.59e2.66 (m,1H), 2.42e2.49 (m,1H);
4.3.3. Compound 3a. 1-(1-(Benzyloxy)but-3-enyl)-4-tert-butylben-
13C NMR (100.6 MHz, CDCl3)
d: 149.5, 147.5, 137.7, 133.5, 128.4, 127.8,
zene. 1H NMR (400 MHz, CDCl3)
d: 7.29e7.42 (m, 9H), 5.82e5.89
127.6, 127.5, 123.7, 117.9, 80.2, 71.0, 42.2; IR n: 3076, 2863, 2452, 1949,
(m, 1H), 5.03e5.12 (m, 2H), 4.51 (d, 1H, J¼11.9 Hz), 4.37e4.40 (m,
1808, 1641, 1606, 1520,1454,1345,1206, 1090, 918, 855, 699 cmꢀ1; EI-
MS m/z: 242 (6),128 (2), 91 (100), 77 (3), 65 (6); HRMS-EI (m/z): [M]þ
calcd for C17H17NO3, 283.1208; found, 283.1212.
1H), 4.30 (d, 1H, J¼11.8 Hz), 2.63e2.68 (m, 1H), 2.45e2.50 (m, 1H),
1.37 (s, 9H); 13C NMR (100.6 MHz, CDCl3)
d: 150.5, 138.8, 138.7,
135.2, 128.3, 127.7, 127.4, 126.5, 125.3, 116.6, 81.0, 70.3, 42.7, 34.5,
31.4; IR
n
: 3064, 3029, 2952, 2866, 1949, 1806, 1641, 1454, 1363,
4.3.10. Compound10a.1-(1-(Benzyloxy)but-3-enyl)-3-nitrobenzene. 1H
1268, 1204, 1092, 1069, 1027, 914, 832, 734, 697 cmꢀ1; EI-MS m/z:
294 (Mþ, 5), 253 (10), 161 (6) 147 (4), 91 (100), 57 (4); HRMS-EI (m/
z): [M]þ calcd for C21H26O, 294.1984; found, 294.1987.
NMR (400 MHz, CDCl3)
d
: 8.21 (s,1H), 8.16 (d,1H, J¼7.8 Hz), 7.69 (d,1H,
J¼7.7 Hz), 7.54 (t, 1H, J¼7.8 Hz), 7.28e7.37 (m, 5H), 5.75e5.84 (m, 1H),
5.02e5.07 (m, 2H), 4.49e4.54 (m, 2H), 4.36 (d, 1H, J¼11.8 Hz),
2.63e2.70 (m, 1H), 2.45e2.52 (m, 1H); 13C NMR (100.6 MHz, CDCl3)
d:
4.3.4. Compound 4a.1-(1-(Benzyloxy)but-3-enyl)-2-chlorobenzene. 1H
148.5, 144.3, 137.8, 133.5, 132.8, 129.4, 128.4, 127.8, 127.7, 122.6, 121.8,
NMR (400 MHz, CDCl3)
d
: 7.60 (d, 1H, J¼1.6 Hz), 7.29e7.58 (m, 7H),
117.9, 80.2, 71.0, 42.3; IR n: 3069, 2865, 1959, 1740, 1641, 1530, 1345,
7.21e7.26 (m, 1H), 5.87e5.91 (m, 1H), 5.05e5.11 (m, 2H), 4.93e4.97
(m, 1H), 4.49 (d, 1H, J¼11.7 Hz), 4.35 (d, 1H, J¼11.7 Hz), 2.52e2.55 (m,
1205, 1092, 1028, 918, 809, 738, 697 cmꢀ1; EI-MS m/z: 242 (6), 128 (2),
92 (8), 91 (100), 77 (2), 65 (5); HRMS-EI (m/z): [M]þ calcd for
C17H17NO3, 283.1208; found, 283.1205.
2H); 13C NMR (100.6 MHz, CDCl3)
d: 139.5, 138.3, 134.5, 132.9, 129.4,
128.5, 128.3, 127.7, 127.5, 127.1, 117.0, 78.0, 71.0, 41.1; IR n: 3067, 3031,
2863, 1950, 1810, 1640, 1439, 1394, 1351, 1206, 1092, 1035, 915, 755,
696 cmꢀ1; EI-MS m/z: 233 (4), 231 (12), 139 (3), 91 (100) 65 (5);
HRMS-EI (m/z): [M]þ calcd for C17H17ClO, 272.0968; found, 272.0977.
4.3.11. Compound 11a. 4-(1-(Benzyloxy)but-3-enyl)benzonitrile. 1H
NMR (400 MHz, CDCl3) d: 7.56e7.62 (m, 3H), 7.45e7.56 (m, 1H),
7.28e7.36 (m, 5H), 5.70e5.77 (m, 1H), 4.99e5.05 (m, 2H), 4.47 (d,
1H, J¼11.8 Hz), 4.39e4.43 (m, 1H), 4.31 (d, 1H, J¼11.8 Hz), 2.57e2.63
4.3.5. Compound 5a.1-(1-(Benzyloxy)but-3-enyl)-4-chlorobenzene. 1H
(m, 1H), 2.41e2.46 (m, 1H); 13C NMR (100.6 MHz, CDCl3)
d: 143.6,
NMR (400 MHz, CDCl3)
d: 7.27e7.36 (m, 9H), 5.75e5.80 (m, 1H),
137.8, 133.6, 131.3, 131.2, 130.4, 129.2, 128.4, 127.7, 127.6, 118.7, 117.8,

K. Murugan et al. / Tetrahedron 67 (2011) 5621e5629
5627
112.6, 80.2, 70.9, 42.3; IR
n
: 3066, 3031, 2863, 2229, 1958, 1826,
5.01e5.07 (m, 2H), 4.48 (d, 1H, J¼11.8 Hz), 4.36e4.39 (m, 1H),
5.08e5.16 (m, 2H), 4.66 (d, 1H, J¼12.0 Hz), 4.46 (d, 1H, J¼12.0 Hz),
4.00 (q, 1H, J¼6.6, 14.0 Hz), 2.51e2.58 (m, 1H), 2.40e2.47 (m, 1H);
1736, 1641, 1584, 1454, 1433, 1344, 1206, 1088, 1073, 918, 801, 737,
693 cmꢀ1; EI-MS m/z: 223 (2), 222 (15), 130 (3), 116 (2), 102 (2), 92
(7), 91 (100), 77 (3), 64 (7); HRMS-EI (m/z): [M]þ calcd for
C18H17NO, 263.1310; found, 263.1305.
13C NMR (100.6 MHz, CDCl3)
d
: 138.7, 136.6, 134.5, 132.5, 129.9,
: 3062, 3027,
128.6, 128.3,127.7,127.4,126.5117.1, 79.7, 701., 40.4; IR
n
2859, 1948, 1808, 1727, 1640, 1494, 1452, 1356, 1090, 1069, 968, 914,
748, 696 cmꢀ1; FABMS m/z: 264 (Mþ, 0.6), 223 (8), 181 (3), 157 (12),
131 (12), 115 (22),105 (30), 91 (100), 83 (22), 77 (16), 57 (43), 65 (6);
HRMS-EI (m/z): [M]þ calcd for C19H21O, 264.1514; found, 264.1586.
4.3.12. Compound 12a. (4-(1-(Benzyloxy)but-3-enyl)phenoxy)(tert-
butyl)dimethylsilane. 1H NMR (400 MHz, CDCl3)
d: 7.26e7.36 (m,
5H), 7.18 (m, 2H), 6.84 (q, 2H, J¼1.8, 6.5 Hz), 5.75e5.81 (m, 1H),
4.99e5.06 (m, 5H), 5.70e5.77 (m, 2H), 4.45 (d, 1H, J¼11.9 Hz),
4.27e4.32 (m, 1H), 4.24 (d, 1H, J¼11.9 Hz), 2.60e2.65 (m, 1H),
2.40e2.45 (m, 1H), 1.00 (s, 9H), 0.22 (m, 6H); 13C NMR (100.6 MHz,
4.3.18. Compound 18a. 1-((1-Cyclohexylbut-3-enyloxy)methyl)ben-
zene. 1H NMR (400 MHz, CDCl3)
d: 7.26e7.36 (m, 5H), 5.75e5.90
CDCl3)
d
: 155.1, 138.6, 135.0, 134.4, 128.3, 128.0, 127.7, 127.4, 119.8,
(m, 1H), 5.03e5.12 (m, 2H), 4.57 (d, 1H, J¼11.5 Hz), 4.47 (d, 1H,
J¼11.5 Hz), 3.18e4.3.21 (m, 1H), 2.30e2.36 (m, 2H), 1.86 (br d, 1H),
1.65e1.76 (m, 4H), 1.53e1.55 (m, 1H), 1.02e1.26 (m, 5H); 13C NMR
116.7, 82.1, 70.1, 42.6, 25.7, 18.2, ꢀ4.3; IR
n: 3449, 2930, 2858, 1607,
1509, 1259, 1092, 915, 839 cmꢀ1; HRMS-EI (m/z): [M]þ calcd for
C23H32O2Si, 368.2172; found, 368.2168.
(100.6 MHz, CDCl3)
71.8, 41.1, 35.3, 29.0, 28.6, 26.6, 26.4, 26.3; IR
d
: 139.1, 135.6, 128.2, 127.7, 127.3, 116.4, 83.3,
: 3064, 3030, 2852,
n
4.3.13. Compound 13a. 2-(1-(Benzyloxy)but-3-enyl)naphthalene. 1H
NMR (400 MHz, CDCl3) d: 7.88e7.93 (m, 3H), 7.81 (s, H), 7.52e7.81
1946, 1809, 1734, 1639, 1496, 1346, 1207, 1069, 1026, 911, 733,
696 cmꢀ1; FABMS m/z: 243 (Mþ, 4), 221 (4), 203 (35), 181 (21), 147
(13), 137(45), 111 (46), 95 (82), 91 (100), 83 (72), 77 (27), 57 (43), 69
(58), 55 (80); HRMS-EI (m/z): [M]þ calcd for C17H24O, 244.1827;
found, 244.1915.
(m, 3H), 7.32e7.39 (m, 5H), 5.83e5.91 (m, 1H), 5.06e5.14 (m, 2H),
4.54e4.61 (m, 2H), 4.37 (d, 1H, J¼11.9 Hz), 2.75e2.83 (m, 1H),
2.56e2.63 (m,1H); 13C NMR (100.6 MHz, CDCl3)
d: 139.3,138.5,134.8,
133.3, 133.2, 128.4, 127.9, 127.8, 127.7, 127.5, 126.1, 125.9, 124.6, 117.1,
81.4, 70.5, 42.5; IR
n
: 3030, 3059, 2860, 1949, 1807, 1640, 1496, 1454,
4.3.19. Compound 19a. (1R,5S)-2-(1-(Benzyloxy)but-3-enyl)-6,6-
1365,1320,1270,1090,1072, 914, 857, 744 cmꢀ1; EI-MS m/z: 288 (Mþ,
1), 248 (4), 247 (22),171 (13), 155 (7),127 (6), 91 (100), 77 (2), 65 (4);
HRMS-EI (m/z): [M]þ calcd for C20H21O, 288.1514; found, 288.1511.
dimethylbicyclo[3.1.1]hept-2-ene. 1H NMR (400 MHz, CDCl3)
d: di-
astereomeric ratio is 3:2; major diastereomers: 7.26e7.33 (m, 5H),
5.85e5.96 (m, 1H), 5.47 (s, 1H), 5.01e5.08 (m, 2H), 4.51e4.58 (m,
1H), 4.28e4.33 (m, 1H), 3.73e3.76 (m, 1H), 2.12e2.45 (m, 7H), 1.31
(s, 3H), 1.20 (d, 1H, J¼8.5 Hz), 0.85 (s, 3H); minor diastereomers:
7.26e7.33 (m, 5H), 5.85e5.96 (m, 1H), 5.47 (s, 1H), 5.01e5.08 (m,
2H), 4.51e4.58 (m, 1H), 4.28e4.33 (m, 1H), 3.73e3.76 (m, 1H),
2.12e2.45 (m, 7H), 1.31 (s, 3H), 1.15 (d, 1H, J¼8.5 Hz), 0.93 (s, 3H);
4.3.14. Compound 14a. 10-(1-(Benzyloxy)but-3-enyl)anthracene. 1H
NMR (400 MHz, CDCl3) d: 9.25 (br s, 1H) 8.46 (s, 1H), 8.18 (br s, 1H),
8.03e8.06 (m, 2H), 7.48e7.50 (m, 4H), 7.23e7.31 (m, 5H), 5.91e5.93
(m, 1H), 5.87e5.91 (m, 1H), 5.11 (dd, 1H J¼17.1, 1.6 Hz), 5.02 (td, 1H,
J¼10.1, 1.5, 0.7 Hz), 4.42 (d, 1H, J¼11.8 Hz), 4.28 (d, 1H, J¼11.7 Hz),
3.23e3.31 (m, 1H), 2.84e2.91 (m, 1H); 13C NMR (100.6 MHz, CDCl3)
13C NMR (100.6 MHz, CDCl3)
d: 147.9, 147.5, 139.0, 135.6, 135.4,
128.2, 127.6, 127.2, 120.8, 120.4, 116.3, 116.1, 81.8, 70.1, 70.0, 53.4,
41.5, 41.2, 41.1, 41.0, 38.3, 38.2, 37.9, 37.8, 31.9, 31.8, 31.3, 26.2, 21.6;
d: 138.5, 135.4, 132.0, 129.3, 128.2, 128.0, 127.4, 126.7, 125.9, 125.3,
124.8, 122.9, 116.7, 77.5, 70.7, 41.3; IR
n
: 3051, 2920, 1946, 1810, 1724,
IR n: 3066, 3029, 2984, 2936, 1944, 1730, 1641, 1496, 1454, 1364,
1674,1640,1495,1370,1206, 1158,1072, 917, 888, 730, 697 cmꢀ1; EI-
MS m/z: 338 (Mþ, 4), 298 (7), 297 (23), 269 (16), 215 (5), 208 (16),
193 (10), 152 (16), 91 (100), 77 (12); HRMS-EI (m/z): [M]þ calcd for
C25H22O, 338.1671; found, 338.1680.
1331, 1203, 1090, 1070, 911, 733, 696 cmꢀ1; EI-MS m/z: 282 (Mþ,
0.3), 241 (5), 149 (3), 131 (5), 105 (12), 91 (100), 77 (7), 65 (4);
HRMS-EI (m/z): [M]þ calcd for C20H26O, 282.1984; found, 282.1979.
4.3.20. Compound 20a. 1-((Hepta-1,5-dien-4-yloxy)methyl)ben-
4.3.15. Compound 15a. 2-(1-(Benzyloxy)but-3-enyl)thiophene. 1H
zene. 1H NMR (400 MHz, CDCl3)
d: 7.26e7.35 (m, 5H), 5.79e5.87
NMR (400 MHz, CDCl3)
d
: 7.29e7.39 (m, 10H), 7.00e7.01 (m, 2H),
(m, 1H), 5.62e5.71 (m, 1H), 5.38e5.44 (m, 1H), 5.04e5.10 (m, 2H),
4.59 (d, 1H, J¼12.0 Hz), 4.37 (d, 1H, J¼12.0 Hz), 3.77 (q, 1H,
J¼6.7 Hz), 2.41e2.45 (m, 1H), 2.28e2.34 (m, 1H), 1.76 (q, 3H,
5.77e5.86 (m, 1H), 5.08e5.13 (m, 2H), 4.66 (t, 1H, J¼6.8 Hz), 4.57
(d, 1H, J¼11.7 Hz), 4.37 (d, 1H, J¼11.8 Hz), 2.72e2.78 (m, 1H),
2.56e2.61 (m, 1H); 13C NMR (100.6 MHz, CDCl3)
d
: 145.8, 138.3,
J¼1.1 Hz); 13C NMR (100.6 MHz, CDCl3)
d
: 138.9, 134.9, 131.5, 129.0,
134.3, 128.3, 127.8, 127.5, 126.3, 125.4, 125.1, 117.3, 76.5, 70.2, 42.8;
128.2, 127.6, 127.3, 116.5, 79.6, 69.7, 40.3, 17.6; IR n: 3030, 2978, 2917,
IR
n
: 3067, 2861, 1950, 1726, 1641, 1454, 1315, 1087, 1071, 916,
2857, 1946, 1673, 1641, 1496, 1454, 1355, 1247, 1205, 1091, 1068, 968,
913, 734, 696 cmꢀ1; EI-MS m/z: 202 (Mþ, 0.1), 161 (11), 135 (1), 105
(2), 63 (7), 91 (100), 77 (2), 65 (6); HRMS-EI (m/z): [M]þ calcd for
C14H18O, 202.1358; found, 202.1351.
702 cmꢀ1; EI-MS m/z: 244 (Mþ, 0.1), 203 (22), 197 (2), 111 (3), 92
(8), 91 (100), 77 (2), 65 (6); HRMS-EI (m/z): [M]þ calcd for
C15H16OS, 244.0922; found, 244.0917.
4.3.16. Compound 16a. 3-(1-(Benzyloxy)but-3-enyl)thiophene. 1H
4.3.21. Compound 21a. 1-((2-Methylhex-5-en-3-yloxy)methyl)ben-
NMR (400 MHz, CDCl3)
d
: 7.29e7.38 (m, 6H), 7.19 (q, 1H, J¼0.9 Hz),
zene. 1H NMR (400 MHz, CDCl3)
d: 7.26e7.37 (m, 5H), 5.86e5.93
7.13 (q, 1H, J¼1.1 Hz), 5.79e5.85 (m, 1H), 5.04e5.11 (m, 2H),
(m, 1H), 5.04e5.13 (m, 2H), 4.58 (d, 1H, J¼11.5 Hz), 4.51 (d, 1H,
4.50e4.54 (m, 2H), 4.34 (d, 1H, J¼11.8 Hz), 2.66e2.73 (m, 1H),
J¼11.5 Hz), 3.19e3.23 (m, 1H), 2.31e1.92 (m, 1H), 1.87e1.92 (m, 1H),
2.48e2.55 (m, 1H); 13C NMR (100.6 MHz, CDCl3)
d: 143.3, 138.5,
0.91e0.99 (m, 6H); 13C NMR (100.6 MHz, CDCl3)
d: 141.8, 138.5,
134.7, 128.3, 127.7, 127.5, 126.1, 126.0, 122.1, 117.0, 77.4, 70.3, 41.7; IR
134.9, 128.4, 128.3, 127.7, 127.4, 126.9, 116.8, 81.1, 70.3, 42.6; IR n:
n
: 3075, 2904, 2863, 1949, 1829, 1750, 1640, 1496, 1454, 1418, 1327,
3066, 3030, 2960, 2872, 1946, 1640, 1454, 1348, 1206, 1094, 1068,
1028, 911, 734, 696 cmꢀ1; EI-MS m/z: 203 (Mþ, 0.3), 203 (20), 163
(7), 162 (10), 105 (2), 98 (10), 91 (100), 83 (9), 77 (2), 65 (7); HRMS-
EI (m/z): [M]þ calcd for C14H20O, 204.1514; found, 204.1505.
1089, 1027, 993, 916, 786, 736,697 cmꢀ1; EI-MS m/z: 244 (Mþ, 0.3),
203 (20), 135 (1), 111 (3), 92 (7), 91 (100), 77 (2), 65 (3); HRMS-EI
(m/z): [M]þ calcd for C15H16OS, 244.0922; found, 244.0917.
4.3.17. Compound 17a. (E)-1-((1-Phenylhexa-1,5-dien-3-yloxy)met-
4.3.22. Compound 22a. 1-((6-Methylhept-1-en-4-yloxy)methyl)ben-
hyl)benzene. 1H NMR (400 MHz, CDCl3)
d: 7.25e7.43 (m, 10H), 6.58
zene. 1H NMR (400 MHz, CDCl3)
d: 7.27e7.36 (m, 5H), 5.81e5.88 (m,
(d, 1H, J¼15.9 Hz), 6.17 (q, 1H, J¼7.9 Hz), 5.89e5.93 (m, 1H),
1H), 5.05e5.12 (m, 2H), 4.60 (d, 1H, J¼11.5 Hz), 4.46 (1H, J¼11.5 Hz),

5628
K. Murugan et al. / Tetrahedron 67 (2011) 5621e5629
3.49e3.52 (m,1H), 2.32e2.35(m, 2H),1.75e1.83 (m, 1H), 1.50e1.57 (m,
1H),1.23e1.29(m,1H), 0.90(d, 3H, J¼6.7Hz), 0.85(d, 3H, J¼6.6 Hz); 13C
J¼6.8 Hz); 13C NMR (100.6 MHz, CDCl3)
d
: 139.9, 134.7, 128.2, 127.2,
: 2929, 1945,
127.0, 116.9, 79.1, 62.9, 39.9, 34.0, 19.1, 17.5, 17.1; IR
n
NMR (100.6 MHz, CDCl3)
d
: 138.9,135.0,128.3,127.8,127.4,116.9, 70.8,
1806, 1741, 1639, 1454, 1380, 1261, 1148, 1090, 1064, 912, 732 cmꢀ1
;
43.5, 38.5, 24.5, 23.3, 22.2; IR
n: 3066, 3030, 2957, 2927, 2868, 1952,
HRMS-EI (m/z): [M]þ calcd for C15H22O, 218.1671; found, 218.1675.
1739,1640,1454,1349,1095,1069, 912, 733, 696 cmꢀ1; EI-MS m/z: 218
(Mþ, 0.6),177 (5),161 (2),115 (2), 92 (7), 91 (100), 77 (2), 65 (4); HRMS-
EI (m/z): [M]þ calcd for C15H22O, 218.1671; found, 218.1662.
4.3.30. Compound 31a. 1-((1-Allylcyclohexyloxy)methyl)benzene. 1H
NMR (400 MHz, CDCl3) d: 7.26e7.44 (m, 5H), 5.91e5.98 (m, 1H),
5.12 (d, 2H, J¼13.0 Hz), 4.45 (s, 2H), 2.39 (d, 2H, J¼7.1 Hz), 1.87e1.90
4.3.23. Compound 23a. 1-((2,2-Dimethylhex-5-en-3-yloxy)methyl)
(m, 2H),1.61e1.71 (m, 3H),1.48e1.54 (m, 2H),1.31e1.44 (m, 3H); 13C
benzene. 1H NMR (400 MHz, CDCl3)
d: 7.27e7.40 (m, 5H), 5.15 (dd,
NMR (100.6 MHz, CDCl3) d: 139.7, 134.2, 128.3, 127.4, 127.1, 117.2,
1H, J¼17.1,1.5 Hz), 5.06 (d,1H, J¼10.1 Hz), 4.69 (d,1H, J¼11.2 Hz), 4.53
75.4, 62.4, 41.9, 34.4, 25.9, 21.9; IR n: 3030, 2935, 2856, 1944, 1741,
(d, 1H, J¼11.2 Hz), 3.11 (dd, 1H, J¼8.4, 3.3 Hz), 2.42e2.44 (m, 1H),
1638, 1496, 1449, 1089, 1063, 911, 732 cmꢀ1; HRMS-EI (m/z): [M]þ
2.29e2.34 (m,1H), 0.99 (s, 3H); 13C NMR (100.6 MHz, CDCl3)
d: 139.2,
calcd for C16H22O, 230.1671; found, 230.1665.
137.4, 128.2, 127.5, 127.3, 116.0, 87.8, 74.3, 36.1, 35.8, 26.4; IR
n: 3067,
3031, 2952, 2868,1946,1823,1639,1454,1389,1362,1218,1097, 986,
910, 733, 696 cmꢀ1; EI-MS m/z: 218 (Mþ, 0.1),177 (6),161 (5),105 (2),
92 (10), 91 (100), 77 (2), 65 (6); HRMS-EI (m/z): [M]þ calcd for
C15H22O, 218.1671; found, 218.1663.
4.4. Allylation of acetals, ketals, and acylals
To a solution of cyclohexanone dimethyl ketal 32 (100 mg,
0.693 mmol) in acetonitrile (2 mL) was added 50 wt % SMAeSiO2
(50 mg, 0.013 mmol); then, allyltrimethylsilane (165 mL, 0.104 mmol)
4.3.24. Compound 25a. 1-((2-Methylpent-4-en-2-yloxy)methyl)ben-
was added dropwise at ambient temperature. The reactants were
stirred for a further 10 min. After the reaction had run to completion
(TLC), brine (10 mL) was added and the reaction mixture was
extractedwithdiethylether(2ꢂ10mL). Thecombinedetherlayerwas
dried over MgSO4, filtered, and concentrated under reduced pressure.
Purificationofthecrudeproductbycolumnchromatographyafforded
pure homoallyl ether 32a as a colorless oil (106 mg, 99%).
zene. 1H NMR (400 MHz, CDCl3)
d
: 7.29e7.43 (m, 5H), 5.96e6.04
(m, 1H), 5.14e5.18 (m, 2H), 4.53 (s, 2H), 2.42 (d, 2H, J¼7.2 Hz), 1.33
(s, 3H); 13C NMR (100.6 MHz, CDCl3)
: 139.8, 134.8, 128.3, 127.4,
d
127.2, 117.4, 75.1, 63.8, 45.2, 25.5; IR n: 3066, 2975, 1947, 2418, 1639,
1454, 1382, 1228, 1148, 1092, 913, 732 cmꢀ1; HRMS-EI (m/z): [M]þ
calcd for C13H18O, 190.1358; found, 190.1350.
4.3.25. Compound 26a. 1-((3-Ethylhex-5-en-3-yloxy)methyl)ben-
4.4.1. Compound 32a. 1-Allyl-1-methoxycyclohexane. 1H NMR
(400 MHz, CDCl3) d: 5.77e5.84 (m, 1H), 5.01e5.06 (m, 2H), 3.16 (s,
zene. 1H NMR (400 MHz, CDCl3)
d
: 7.24e7.38 (m, 5H), 5.80e5.91 (m,
1H), 5.07e5.13 (m, 2H), 4.39 (s, 2H), 2.34 (d, 2H, J¼7.1 Hz),1.55e1.62
3H), 2.20 (d, 2H, J¼7.2 Hz), 1.68 (d, 2H, J¼13.3 Hz), 1.48e1.57 (m,
(m, 4H), 0.90 (t, 3H, J¼7.5 Hz); 13C NMR (100.6 MHz, CDCl3)
d
: 139.6,
: 3027,
3H), 1.38e1.43 (m, 2H), 1.20e1.30 (m, 4H), 0.83e0.89 (m, 1H); 13C
134.3, 128.2, 127.3, 127.1, 117.1, 79.0, 62.6, 38.7, 26.9, 7.5; IR
n
NMR (100.6 MHz, CDCl3)
d: 134.0, 117.0, 74.8, 48.0, 40.9, 33.8, 25.8,
2933, 1946, 1869, 1806, 1639, 1496, 1453, 1381, 1065, 913, 734 cmꢀ1
;
21.7; IR n: 2924, 2851, 1739, 1454, 1359, 1082, 990, 900, 808,
HRMS-EI (m/z): [M]þ calcd for C15H22O, 218.1671; found, 218.1675.
792 cmꢀ1; EI-MS m/z: 155 (Mþþ1, 2), 154 (Mþ, 1), 149 (8), 141 (3),
129 (3), 113 (100), 111 (11), 91 (13), 81 (51), 79 (14), 57 (22); HRMS-
EI (m/z): [M]þ calcd for C10H18O, 154.1358; found, 154.1360.
4.3.26. Compound 27a. 1-((4-Propylhept-1-en-4-yloxy)methyl)ben-
zene. 1H NMR (400 MHz, CDCl3)
: 7.23e7.36 (m, 5H), 5.80e5.90
d
(m, 1H), 5.06e5.08 (m, 2H), 4.38 (s, 2H), 2.33 (d, 2H, J¼7.2 Hz),
4.4.2. Compound 32a. 1-(2-Methoxypent-4-en-2-yl)benzene. 1H
1.49e1.55 (m, 4H), 1.32e1.40 (m, 4H), 0.95 (t, 3H, J¼7.1 Hz); 13C
NMR (400 MHz, CDCl3)
5.62e5.73 (m,1H), 5.01e5.05 (m, 2H), 3.10 (s, 3H), 2.49 (m, 2H),1.54
(s, 3H); 13C NMR (100.6 MHz, CDCl3)
: 144.7, 134.1, 128.1, 126.9,
126.2, 117.6, 78.7, 50.4, 47.2, 22.8; IR : 3075, 2979, 2934, 2824,1950,
d: 7.34e7.41 (m, 4H), 7.25e7.29 (m, 1H),
NMR (100.6 MHz, CDCl3) d: 139.6, 134.4, 128.2, 127.3, 127.1, 117.1,
78.7, 62.26, 39.8, 37.5, 16.3, 14.6; IR
n
: 3030, 2872, 1944, 1825, 1740,
d
1639, 1454, 1378, 1154, 1060, 912, 732 cmꢀ1; HRMS-EI (m/z): [M]þ
n
calcd for C16H24O, 246.1984; found, 246.1990.
1811, 1737, 1639, 1493, 1446, 1371, 1287, 1221, 1161, 1071, 997, 915,
838, 764 cmꢀ1; EI-MS m/z: 176 (Mþ, 0.3), 161 (1), 155 (1), 145 (5),
136 (8), 135 (100), 129 (8), 105 (9), 91 (12), 77 (11), 65 (2); HRMS-EI
(m/z): [M]þ calcd for C12H16O, 176.1201; found, 176.1204.
4.3.27. Compound 28a. 1-((4-Methyloct-1-en-4-yloxy)methyl)ben-
zene. 1H NMR (400 MHz, CDCl3)
d: 7.26e7.39 (m, 5H), 5.88e5.95 (m,
1H), 5.10e5.14 (m, 2H), 4.45 (s, 2H), 2.36e2.40 (m, 2H),1.56e1.61 (m,
2H), 1.32e1.42 (m, 4H), 1.24 (s, 3H), 0.95 (t, 3H, J¼7.1 Hz); 13C NMR
4.4.3. Compound34a.1-Methoxy-4-(1-methoxybut-3-enyl)benzene. 1H
(100.6 MHz, CDCl3)
d: 139.77, 134.67, 128.3, 127.3, 127.1, 117.2, 76.9,
NMR (400 MHz, CDCl3)
d
: 7.22 (d, 2H, J¼8.5 Hz), 6.89 (d, 2H, J¼8.5 Hz),
63.2, 42.9, 37.7, 25.6, 23.4, 23.3, 14.2; IR
n
: 3030, 2872, 1944, 1825,
5.71e5.81 (m,1H), 5.00e5.07 (m, 2H), 4.12 (t, 1H, J¼6.8 Hz), 3.8 (s, 3H),
1740, 1639, 1454, 1378, 1154, 1060, 912, 732 cmꢀ1; HRMS-EI (m/z):
3.2 (s, 3H), 2.54e2.61 (m,1H), 2.36e2.42 (m,1H); 13C NMR (100.6 MHz,
[M]þ calcd for C16H24O, 232.1827; found, 232.1817.
CDCl3) d: 159.1,134.9,133.6,127.9,116.7,113.7, 83.1, 56.3, 55.2, 42.4; IR n:
3075, 2979, 2934, 2820, 2060, 1611, 1512, 1463, 1354, 1302, 1247, 1173,
1096,1036, 915, 831 cmꢀ1;EI-MSm/z:192(Mþ, 0.1), 161 (9), 152 (8), 151
(100), 135 (13), 121 (3), 108 (4), 91 (5), 77 (4), 65 (2); HRMS-EI (m/z):
[M]þ calcd for C12H16O2, 192.1150; found, 192.1144.
4.3.28. Compound 29a. 1-((3-Methyl-1-phenylhex-5-en-3-yloxy)
methyl)benzene. 1H NMR (400 MHz, CDCl3)
d: 7.35e7.49 (m, 8H),
7.26e7.29 (m, 2H), 5.97e6.04 (m,1H), 5.20e5.25 (m, 2H), 4.57 (s, 2H),
2.79e2.83 (m, 2H), 2.52 (t, 2H, J¼6.8 Hz), 1.93e2.00 (m, 2H), 1.39 (s,
3H); 13C NMR (100.6 MHz, CDCl3)
d: 142.9, 139.6, 134.4, 128.5, 128.4,
4.4.4. Compound 35a. 1-(3-Methoxyhex-5-en-2-yl)benzene. 1H NMR
127.4, 127.3, 125.8, 117.7, 76.7, 63.4, 43.1, 40.1, 30.0, 23.4; IR
n
: 3067,
(400 MHz, CDCl3) d: diastereomeric ratio is 1:2.5; major di-
2969, 1945, 1806, 1742, 1639, 1453, 1384, 1257, 1088, 911, 732 cmꢀ1
;
astereomers: 7.20e7.33 (m, 5H), 5.80e5.87 (m, 1H), 4.99e5.09 (m,
2H), 3.38 (s, 3H), 3.31e3.35 (m, 1H), 2.89e2.92 (m, 1H), 2.21e2.22 (m,
2H), 1.34 (d, 3H, J¼7.0 Hz); minor diastereomers: 7.20e7.33 (m, 5H),
5.80e5.87 (m, 1H), 4.99e5.09 (m, 2H), 3.33 (s, 3H), 3.31e3.35 (m, 1H),
2.96e3.03 (m, 1H), 2.02e2.10 (m, 2H), 1.30 (d, 3H, J¼7.2 Hz); 13C NMR
HRMS-EI (m/z): [M]þ calcd for C20H24O, 280.1827; found, 280.1820.
4.3.29. Compound 30a. 1-((2,3-Dimethylhex-5-en-3-yloxy)methyl)
benzene. 1H NMR (400 MHz, CDCl3)
: 7.25e7.38 (m, 5H), 5.92e5.98
d
(m, 1H), 5.08e5.13 (m, 2H), 4.44 (s, 2H), 2.36e2.40 (m, 2H),
2.00e2.04 (m, 1H), 1.14 (s, 3H), 0.98 (d, 3H, J¼6.8 Hz), 0.93 (d, 3H,
(100.6 MHz, CDCl3) d: 144.8, 143.9, 135.4, 134.9, 128.3, 128.2, 128.1,
127.9, 126.2, 126.1, 116.8, 85.6, 85.4, 58.1, 57.9, 43.3, 42.5, 35.8, 35.3, 17.1,

K. Murugan et al. / Tetrahedron 67 (2011) 5621e5629
5629
16.6; IR
n
: 3077, 2976, 2931, 2823, 1944, 1810, 1640, 1602, 1494, 1453,
Supplementary data
1376, 1224, 1096, 997, 912, 760, 700 cmꢀ1; EI-MS m/z: 190 (Mþ, 0.1),
150 (4), 149 (37), 117 (14), 105 (14), 91 (10), 85 (100), 77 (7), 54 (17);
HRMS-EI (m/z): [M]þ calcd for C13H18O, 190.1358; found, 190.1350.
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.tet.2011.05.093.
4.4.5. Compound 36a. 2-(1-Phenylbut-3-enyloxy)ethanol. 1H NMR
References and notes
(400 MHz, CDCl3)
d: 7.25e7.36 (m, 5H), 5.75e5.82 (m, 1H),
5.02e5.09 (m, 2H), 4.30 (q, 1H, J¼5.6, 7.7 Hz), 3.68 (br s, 2H),
1. Hosomi, A.; Sakurai, H. Tetrahedron Lett. 1976, 17, 1295e1298.
2. Sakurai, H. Pure Appl. Chem. 1982, 54, 1e22.
3.37e3.47 (m, 2H), 2.42e2.60 (m, 2H), 2.13 (br s, 1H); 13C NMR
3. Sakurai, H.; Sasaki, K.; Hayashi, J.; Hosomi, A. J. Org. Chem. 1984, 49, 2808e2809.
4. Sakurai, H. Pure Appl. Chem. 1985, 57, 1759e1770.
5. Hosomi, A. Acc. Chem. Res. 1988, 21, 200e206.
(100.6 MHz, CDCl3) d: 141.7, 134.7, 128.4, 127.7, 126.6, 117.2, 82.3,
69.9, 61.9, 42.5; IR n: 3412, 3076, 2929, 1952, 1641, 1453, 1353, 1107,
915, 758, 701 cmꢀ1; HRMS-EI (m/z): [M]þ calcd for C12H16O2,
6. Hosomi, A.; Miura, K. Bull. Chem. Soc. Jpn. 2004, 77, 835e851.
7. Hosomi, A.; Endo, M.; Sakurai, H. Chem. Lett. 1976, 941e942.
8. Hosomi, A.; Endo, M.; Sakurai, H. Chem. Lett. 1978, 499e500.
9. Tsunoda, T.; Suzuki, M.; Noyori, R. Tetrahedron Lett. 1980, 21, 71e74.
10. Sakurai, H.; Sasaki, K.; Hosomi, A. Tetrahedron Lett. 1981, 22, 745e748.
11. Noyori, R.; Murata, S.; Suzuki, M. Tetrahedron 1981, 37, 3899e3910.
12. Hathaway, S. J.; Paquette, L. A. J. Org. Chem. 1983, 48, 3351e3353.
13. Trehan, A.; Vij, A.; Walia, M.; Kaur, G.; Verma, R. D.; Trehan, S. Tetrahedron Lett.
1993, 34, 7335e7338.
14. Hollis, T. K.; Robinson, N. P.; Whelan, J.; Bosnich, B. Tetrahedron Lett. 1993, 34,
4309e4312.
15. Mayr, H.; Gorath, G.; Bauer, B. Angew. Chem., Int. Ed. Engl. 1994, 33, 788e789.
16. Komatsu, N.; Uda, M.; Suzuki, H.; Takahashi, T.; Domae, T.; Wada, M. Tetrahe-
dron Lett. 1997, 38, 7215e7218.
192.1150; found, 192.1152.
4.4.6. Compound 37a. 2-(1-(2-Bromophenyl)but-3-enyloxy)ethanol. 1H
NMR (400 MHz, CDCl3) d: 7.45e7.53 (m, 2H), 7.32e7.35 (m, 1H),
7.11e7.15 (m, 1H), 5.85e5.90 (m, 1H), 5.06e5.13 (m, 2H), 4.78 (q, 1H,
J¼4.4, 8.1 Hz), 3.71 (br s, 2H), 3.39e3.52 (m, 2H), 2.38e2.54 (m, 2H),
2.15 (br s,1H); 13C NMR (100.6 MHz, CDCl3)
d: 140.8,134.5,132.7,128.9,
127.7, 127.6, 122.8, 117.4, 80.4, 70.3, 61.8, 41.1; IR
n
: 3400, 3073, 2926,
1927, 1838, 1640, 1437, 1346, 1110, 915 cmꢀ1; EI-MS m/z: 271(Mþþ1,
0.4), 270 (Mþ, 0.2), 231 (38), 229 (40), 209 (43), 199 (22), 185 (19), 130
(100), 129 (55), 91 (11), 77 (12), 65 (2); HRMS-EI (m/z): [M]þ calcd for
C12H15BrO2, 270.0255; found, 270.0250.
17. Ishii, A.; Kotera, O.; Saeki, T.; Mikami, K. Synlett 1997, 1145e1146.
18. Yadav, J. S.; Subba Reddy, B. V.; Srihari, P. Synlett 2001, 673e675.
19. Wieland, L. C.; Zerth, H. M.; Mohan, R. S. Tetrahedron Lett. 2002, 43, 4597e4600.
20. Watahiki, T.; Akabane, Y.; Mori, S.; Oriyama, T. Org. Lett. 2003, 5, 3045e3048.
21. Zerth, H. M.; Leonard, N. M.; Mohan, R. S. Org. Lett. 2003, 5, 55e57.
22. Jung, M. E.; Maderna, A. J. Org. Chem. 2004, 69, 7755e7757.
23. Jung, M. E.; Maderna, A. Tetrahedron Lett. 2004, 45, 5301e5304.
24. Wadamoto, M.; Yamamoto, Y. J. Am. Chem. Soc. 2005, 127, 14556e14557.
25. Anazalone, P. W.; Baru, A. R.; Danielson, E. M.; Hayes, P. D.; Nguten, M. P.;
Panico, A. F.; Smith, R. C.; Mohan, R. S. J. Org. Chem. 2005, 70, 2091e2096.
26. Arai, S.; Sudo, Y.; Nishida, A. Tetrahedron 2005, 61, 4639e4642.
27. Lucero, C. G.; Woerpel, K. A. J. Org. Chem. 2006, 71, 2641e2647.
28. Reddy, U. C.; Bondalapati, S.; Saikia, A. K. Eur. J. Org. Chem. 2009, 1625e1629.
29. Kumar, R. S. C.; Reddy, G. V.; Babu, K. S.; Rao, J. M. Chem. Lett. 2009, 38, 564e565.
30. Denmark, S. E.; Wilson, T. M. J. Am. Chem. Soc. 1989, 111, 3475e3476.
31. Kaur, G.; Manju, K.; Trehan, S. Chem. Commun. 1996, 581e582.
32. Kaur, G.; Kaushik, M.; Trehan, S. Tetrahedron Lett. 1997, 38, 2521e2524.
33. Kuhnert, N.; Peverley, J.; Robertson, J. Tetrahedron Lett. 1998, 39, 3215e3216.
34. Ishihara, K.; Hasegawa, A. Angew. Chem., Int. Ed. 2001, 40, 4077e4079.
35. Ishihara, K.; Hiraiwa, Y.; Yamamoto, H. Synlett 2001, 1851e1854.
36. Ishihara, K.; Hasegawa, A.; Yamamoto, H. Synlett 2002, 1299e1301.
37. Cossy, J.; Lutz, F.; Alauze, V.; Meyer, C. Synlett 2002, 45e48.
38. Kampen, D.; List, B. Synlett 2006, 2589e2592.
4.4.7. Compound 38a. 1-Phenylbut-3-enyl acetate. 1H NMR (400 MHz,
CDCl3)
5.04e5.11 (m, 2H), 2.07e2.68 (m, 2H), 2.07 (s, 3H); 13C NMR
(100.6 MHz, CDCl3) : 170.1, 140.1, 133.3, 128.4, 127.9, 126.5, 118.0, 75.1,
40.7, 21.2; IR
d: 7.25e7.35 (m, 5H), 5.82 (q, 1H, J¼6.1 Hz), 5.67e5.74 (m, 1H),
d
n
: 3078, 2939, 1740, 1643, 1495, 1433, 1372, 1233, 1022,
920, 760, 699 cmꢀ1; EI-MS m/z: 190 (Mþ, 0.2), 150 (6), 149 (64), 145,
129 (10), 115 (7), 107 (100), 105 (8), 91 (7), 79 (15), 77 (14); HRMS-EI
(m/z): [M]þ calcd for C12H14O2, 190.0994; found, 190.0992.
4.4.8. Compound 39a. 1-(4-Chlorophenyl)but-3-enyl acetate. 1H NMR
(400 MHz, CDCl3)
(m, 1H), 2.59e2.66 (m, 1H), 2.49e2.55 (m, 1H), 2.06 (s, 3H); 13C NMR
(100.6 MHz, CDCl3) : 170.1, 138.5, 133.7, 132.8, 128.6, 127.9, 118.3, 74.4,
40.5, 21.1; IR
d: 7.25e7.32 (m, 4H), 5.74e5.77 (m, 1H), 5.04e5.08
d
n
: 3079, 2928, 1738, 1643, 1494, 1372, 1234, 1091, 1014,
920, 824 cmꢀ1; EI-MS m/z: 224 (Mþ, 0.5), 185 (14), 183 (41), 156 (26),
143 (24),141 (100),139 (83), 129 (15),111 (31), 77 (22); HRMS-EI (m/z):
[M]þ calcd for C12H13ClO2, 224.0604; found, 224.0595.
ꢀ
ꢀ
39. Kampen, D.; Ladepeche, A.; Claben, G.; List, B. Adv. Synth. Catal. 2008, 350, 962e966.
40. Barbero, M.; Bazzi, S.; Cadamuro, S.; Dughera, S.; Piccinini, C. Synthesis 2010, 315e319.
41. Kataki, D.; Phukan, P. Tetrahedron Lett. 2009, 50, 1958e1960.
42. Huang, X. R.; Chen, C.; Lee, G. H.; Peng, S. M. Adv. Synth. Catal.2009, 351, 3089e3095.
43. Murugan, K.; Srimurugan, S.; Chen, C. Chem. Commun. 2010, 1127e1129.
44. Nagaraju, P.; Pasha, N.; Saiprasad, P. S.; Lingaiah, N. Green Chem. 2007, 9,
1126e1129.
Acknowledgements
45. Rafiee, E.; Joshaghani, M.; Eavani, S.; Rashidzadeh, S. Green Chem. 2008,10, 982e989.
46. Xu, L.;Wang, Y.; Yang, X.;Yu, X.; Guo, Y.;Clark, J. H. Green Chem. 2008,10, 746e755.
47. Geboers, J.; Vyver, S. V. D.; Carpentier, K.; Blochouse, K. D. Chem. Commun. 2010,
3577e3579.
48. Firouzabadi, H.; Jafari, A. A. J. Iran. Chem. Soc. 2005, 2, 85e114 and references
cited therein.
49. Yadav, J. S.; Subba Reddy, B. V.; Pandurangam, T.; Jayasudan Reddy, Y.; Gupta,
M. K. Catal. Commun. 2008, 9, 1297e1301.
50. Motokura, K.; Yoneda, H.; Miyaji, A.; Baba, T. Green Chem. 2010, 12, 1373e1375.
The authors thank Ms. L.M. Hsu at the Instruments Center, Na-
tional Chung Hsing University, for her help in obtaining HRMS, and
the National Science Council of the Republic of China, Taiwan, for
financially supporting this research under Contract NSC 97-2113-
M-259-002-MY3. Ted Knoy is appreciated for his editorial
assistance.