Indium and zinc-mediated Barbier-type addition reaction of 2,3-allenals with allyl bromide: An efficient synthesis of 1,5,6-alkatrien-4-ols

Article abstract of DOI:10.1039/b812869c

A zinc or indium-mediated Barbier-type addition reaction of 2,3-allenals with allyl bromide in a mixed medium of aqueous NH₄Cl and THF (5: 2) was developed to provide an efficient route to 1,5,6-alkatrien-4-ols, which is synthetically very useful. No 1,4-addition reaction was observed. Depending on the substrates, both indium and activated zinc afforded the 1,2-addition products in moderate to excellent yields: for terminal allenals, activated zinc was better while in other cases the yields with indium were relatively higher.

Full text of DOI:10.1039/b812869c

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Indium and zinc-mediated Barbier-type addition reaction of 2,3-allenals with
allyl bromide: an efficient synthesis of 1,5,6-alkatrien-4-ols†
Wangqing Kong, Chunling Fu and Shengming Ma*
Received 1st August 2008, Accepted 26th August 2008
First published as an Advance Article on the web 27th October 2008
DOI: 10.1039/b812869c
A zinc or indium-mediated Barbier-type addition reaction of 2,3-allenals with allyl bromide in a mixed
medium of aqueous NH4Cl and THF (5 : 2) was developed to provide an efficient route to
1,5,6-alkatrien-4-ols, which is synthetically very useful. No 1,4-addition reaction was observed.
Depending on the substrates, both indium and activated zinc afforded the 1,2-addition products in
moderate to excellent yields: for terminal allenals, activated zinc was better while in other cases the
yields with indium were relatively higher.
Introduction
Results and discussion
Recently, much attention has been paid to the transition metal-
catalyzed or mediated reaction of functionalized allenes.1,2 In the
case of 2,3-allenols, we and others have developed some method-
ologies for the synthesis of 2,5-dihydrofurans,3 a-methylene
lactones,4 vinylic epoxides,5 and a- or b-amino alcohols6 starting
from 2,3-allenols. A number of methods have been reported
for the synthesis of 2,3-allenols: (1) the reactions of the mono-
O-tetrahydropyran-2-yl derivatives of butyn-1,4-diols,7 allenic
ketones,8 4-chlorobut-2-yn-1-ol,9 or 2,3-allenoates10 with LiAlH4
or DIBAL-H; (2) the Sn(II)-,11 Cr(II)-11 or In-12 mediated reaction
of propargylic bromides with aldehydes or ketones; (3) the reaction
of 1,2-allenyl lithium with aldehydes13 or ketones;13 (4) the Cu(I)-
mediated homologation of terminal propargylic alcohols.14 On
the other hand, the Barbier-type reaction between allyl halide
and carbonyl compounds to afford homoallylic alcohols in
aqueous media has become a very useful synthetic transforma-
tion. The metals that have been used in the aqueous Barbier-
type reactions include aluminium,15 magnesium,16 manganese,17
zinc,18 antimony,19 gallium,20 indium,21 bismuth,22 tin,23 lead,24 and
cadmium,25 etc. Of these metals, zinc offers the greatest potential
for industrial application because of its relative low cost and
ready availability. Indium26 has the lowest first ionization potential
relative to zinc, tin and magnesium. Therefore, it is facile to
effect SET (single electron transfer) processes. In addition, it is
not sensitive to boiling water or alkali and does not form oxides
readily in air, which makes indium a promising metal for aqueous
Barbier-type reactions. Herein, we wish to report our recent studies
on Barbier-type allylations of 2,3-allenals with allyl bromide using
indium and activated zinc in water.
Synthesis of Starting Materials
4-Mono-substituted or 4,4-disubstituted 2,3-allenals were pre-
pared from the reaction of 1,2-allenyl lithium with DMF by a
modified procedure developed by us (Table 1).13b
2-Substituted 2,3-allenals are easily available from 2,3-allenols
by Swern oxidation (Table 2).27
As a starting point, the Barbier-type addition reaction of 4,4-
pentamethylenebutadienal 1a was chosen to establish the protocol.
Some representative results are listed in Table 3. From Table 3,
it was observed that with 2 equiv. of indium the reaction of
2 equiv. of allyl bromide with 1a in a mixed solvent of THF and
water (2 : 5) at room temperature afforded 1,1-pentamethylene-
1,2,6-heptatrien-4-ol 2a in 59% yield (entry 1, Table 3). By using
saturated aqueous NH4Cl solution instead of water, the yield of the
product was improved greatly to 95% (compare entry 6 with entries
1–3, Table 3). With a lesser or greater amount of saturated aqueous
NH4Cl solution, the yield dropped (entries 7 and 8, Table 3). We
also observed that 2 equiv. of indium are necessary (compare entry
6 with entries 4 and 5, Table 3). Thus, conditions A (2 equiv. of
allyl bromide, 2 equiv. of metal, NH4Cl (sat. aq.) : THF = 5 : 2,
rt) were established as the optimized reaction conditions. When
indium was replaced with zinc powder, the reaction afforded 2a
in 37% (entry 9, Table 3). The isolated yield was improved to
Table 1 Preparation of 4,4-disubstituted or 4-mono-substituted 2,3-
allenals
Entry
R1
R2
Yield of 1 (%)
Laboratory of Molecular Recognition and Synthesis, Department of Chem-
istry, Zhejiang University, Hangzhou 310027, Zhejiang, People’s Republic
of China. E-mail: masm@mail.sioc.ac.cn; Fax: (+86) 21-62609305
† Electronic supplementary information (ESI) available: The spectro-
scopic data (1H and 13C NMR) for all the new compounds. See DOI:
10.1039/b812869c
1
2
3
4
5
-(CH2)5-
n-C4H9
c-C6H11
n-C7H15
n-C10H21
50 (1a)
23 (1b)
51 (1d)
36 (1e)
37 (1f)
n-C4H9
H
H
H
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Table 2 Preparation of 2-substituted 2,3-allenals
in a mixed solvent of saturated aqueous NH4Cl solution and
THF, providing an efficient route to 1,5,6-alkatrien-4-ols. Due
to the synthetic potential of the products, easy availability of the
starting materials, and mild reaction conditions, this method may
be useful in organic synthesis. Further studies on the scope and
synthetic applications of this reaction are being carried out in our
laboratory.
Entry
R1
R2
R3
Yield of 1 (%)
1
2
3
4
5
n-C4H9
H
H
H
H
CH3
80 (1c)
85 (1g)
75 (1h)
54 (1i)
81 (1j)
Experimental section
H
n-C10H21
n-C7H15
Allyl
H
H
Synthesis of 2-substituted-2,3-allenals via the reaction of
1,2-allenyl lithium with DMF
-(CH2)5-
n-C3H7
(1) Synthesis of 4,4-pentamethylenebutadienal (1a).
Typical procedure
Table 3 Effect of metals and solvents on the allylation of 4,4-
pentamethylene butadienal (1a)
To a solution of vinylidenecyclohexane (3.21 g, 29.7 mmol) and
THF (30 mL) was slowly added dropwise n-butyl lithium (11.1 mL,
2.5 M in hexane, 27.75 mmol) at -60 ◦C with stirring under a
nitrogen atmosphere. After being stirred for 1.2 h at -55 ◦C,
the mixture was cooled to -70 ◦C and a solution of anhydrous
dimethylformamide (3.5 mL, d = 0.947, 3.31 g, 45.0 mmol) in
anhydrous THF (10 mL) was added dropwise at this temperature.
After being stirred at -70 ◦C for an additional 2.0 h, the mixture
was poured into 500 mL of HCl (0.1 M, 0 ◦C) with vigorous
stirring. The mixture was extracted with diethyl ether (50 mL ¥
3) after returning to room temperature. The combined organic
extract was washed with ice-water (40 mL ¥ 3) and dried over
anhydrous Na2SO4. Evaporation and column chromatography on
silica gel (petroleum ether–ethyl acetate = 200 : l) afforded 1a13b
(1.90 g, 50%): liquid, 1H NMR (400 MHz, CDCl3) d 9.38 (d, J =
7.2 Hz, 1H), 5.70–5.61 (m, 1H), 2.30–2.15 (m, 4H), 1.68–1.59 (m,
4H), 1.58–1.50 (m, 2H); 13C NMR (75 MHz, CDCl3) d 214.3,
192.9, 107.7, 96.8, 30.0, 26.9, 25.5.
Yield of
Entry
Metal
Solvent
Time/h
2a (%)a
1
2
3
4
5
6
7
8
9
In
In
H2O : THF = 5 : 2
45.5
16
14
72
48
4.3
17
59
64
84
45
64
95
54
40
37
80
NH4Cl (2 M) : THF = 5 : 2
NH4Cl (4 M) : THF = 5 : 2
NH4Cl (sat. aq.) : THF = 5 : 2
NH4Cl (sat. aq.) : THF = 5 : 2
NH4Cl (sat. aq.) : THF = 5 : 2
NH4Cl (sat. aq.) : THF = 1 : 2
In
Inb
Inc
In
In
In
NH4Cl (sat. aq.) : THF = 10 : 1 27
Zn
NH4Cl (sat. aq.) : THF = 5 : 2
17.5
16
10
Znd
NH4Cl (sat. aq.) : THF = 5 : 2
a Isolated yield. b 1.1 equiv. of indium were used. c 1.5 equiv. of indium were
used. d Activated Zn powder.
The following compounds were prepared according to this proce-
dure.
80% when activated zinc powder13b was applied (entry 10, Table 3,
conditions B).
Subsequently, the scope of the allylation of different 2,3-allenals
was studied with some typical results summarized in Table 4.
Various differently substituted 2,3-allenals were successfully used
to afford 1,5,6-alkatrien-4-ols in moderate to good yields. 4,4-
Disubstituted (entries 1–4, Table 4), 2,4-disubstituted (entries 5
and 6, Table 4), 4-mono-substituted (entries 7–12, Table 4), 2-
mono-substituted (entries 13–18, Table 4), and fully substituted
2,3-allenals (entries 19 and 20, Table 4) all afforded the expected
products smoothly, indicating the wide scope of this reaction. In
most cases, the yields of 2,3-allenols with indium were higher
than those with activated zinc (entries 1–12 and 19–20, Table 4),
however, the reaction of terminal allenals with allyl bromide and
activated zinc afforded the corresponding products in higher yields
(entries 13–18, Table 4). In addition, it should be noted that
(2) Synthesis of 4-butyl-2,3-octadienal (1b)
The reaction of n-butyl lithium (3.4 mL, 2.5 M in hexane,
8.5 mmol), 3-butyl-1,2-heptadiene (1.41 g, 9.3 mmol), dimethylfor-
mamide (1.06 mL, d = 0.947, 1.00 g, 13.8 mmol), and anhydrous
THF (29 mL) afforded 1b28 (0.35 g, 23%): liquid, 1H NMR
(300 MHz, CDCl3) d 9.42 (d, J = 7.5 Hz, 1H), 5.83–5.75 (m,
1H), 2.17–2.05 (m, 4H), 1.49–1.20 (m, 8H), 0.89 (t, J = 7.0 Hz,
6H).
(3) Synthesis of 4-cyclohexylbutadienal (1d)
The reaction of n-butyl lithium (8.5 mL, 2.5 M in hexane,
21.25 mmol), cyclohexyl-1,2-propadiene (2.76 g, 22.6 mmol),
dimethylformamide (2.8 mL, d = 0.947, 2.65 g, 36.3 mmol), and
=
in all the cases, 1,4-addition reaction to the conjugated C C
1
anhydrous THF (60 mL) afforded 1d (1.62 g, 51%): liquid, H
bond in the allenals was not observed, indicating the excellent
chemoselectivity.
NMR (300 MHz, CDCl3) d 9.46 (d, J = 7.5 Hz, 1H), 5.89–5.81
(m, 1H), 5.75 (t, J = 6.0 Hz, 1H), 2.28–2.13 (m, 1H), 1.89–
1.59 (m, 5H), 1.40–1.08 (m, 5H); 13C NMR (75 MHz, CDCl3)
d 218.6, 192.4, 102.0, 99.5, 36.6, 32.84, 32.80, 25.7; IR (neat),
n (cm-1) 2926, 2852, 1941, 1692, 1449, 1112, 1091; MS (70 ev,
EI) m/z (%) 150 (M+, 5.33), 107 (M+ - C3H7, 100); elemental
Conclusions
In conclusion, we have developed a convenient aqueous allylation
reaction of 2,3-allenals with allyl bromide by using zinc or indium
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Table 4 Allylation of 2,3-allenals mediated by In or Zn
1
Entry
R1
R2
R3
Metal
Time/h
Yield of 2 (%)a
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
-(CH2)5-
-(CH2)5-
n-C4H9
n-C4H9
n-C4H9
n-C4H9
c-C6H11
c-C6H11
n-C7H15
n-C7H15
n-C10H21
n-C10H21
H
H (1a)
In
Zn
In
Zn
In
Zn
In
Zn
In
Zn
In
Zn
In
Zn
In
4.3
16
7.5
13
12
17
26.3
27
12
10.4
10
10
11
10
10.3
12
9.5
17
95 (2a)
80 (2a)
84 (2b)
77 (2b)
65 (2c)
57 (2c)
86 (2d)
74 (2d)
89 (2e)
81 (2e)
85 (2f)
80 (2f)
84 (2g)
84 (2g)
82 (2h)
88 (2h)
73 (2i)
75 (2i)
72 (2j)
69 (2j)
H (1a)
n-C4H9
H (1b)
H (1b)
n-C4H9
H
H
H
H
H
H
H
H
H
H
H
H
H
H
CH3 (1c)
CH3 (1c)
H (1d)
H (1d)
H (1e)
H (1e)
H (1f)
H (1f)
n-C10H21 (1g)
n-C10H21 (1g)
n-C7H15 (1h)
n-C7H15 (1h)
Allyl (1i)
Allyl (1i)
n-C3H7 (1j)
n-C3H7 (1j)
H
H
H
H
Zn
In
Zn
In
H
-(CH2)5-
-(CH2)5-
9.2
11
Zn
a Isolated yield.
analysis: calcd for C10H14O: C, 79.96; H, 9.39; found: C, 79.97; H,
9.39.
analysis: calcd for C14H24O: C, 80.71; H, 11.61; found: C, 80.74;
H, 11.55.
Synthesis of 2-substituted-2,3-allenals via the oxidation of
2,3-allenols
(4) Synthesis of 2,3-undecadienal (1e)
The reaction of n-butyl lithium (8.0 mL, 2.5 M in hexane,
20.0 mmol), 1,2-decadiene (3.04 g, 22.0 mmol), dimethylfor-
mamide (3.0 mL, d = 0.947, 2.85 g, 38.9 mmol), and anhydrous
THF (60 mL) afforded 1e (1.20 g, 36%): liquid, 1H NMR
(300 MHz, CDCl3) d 9.46 (d, J = 7.2 Hz, 1H), 5.82–5.69 (m,
2H), 2.16 (qd, J = 7.1, 3.0 Hz, 2H), 1.52–1.40 (m, 2H), 1.38–1.18
(m, 8H), 0.86 (t, J = 6.8 Hz, 3H); 13C NMR (75 MHz, CDCl3) d
219.1, 192.3, 98.5, 96.3, 31.7, 28.9, 28.8, 28.7, 27.4, 22.5, 14.0; IR
(neat), n (cm-1) 2956, 2927, 2856, 2798, 1944, 1693, 1466, 1378,
1107, 1080; MS (70 ev, EI) m/z (%) 166 (M+, 6.81), 81 (100);
elemental analysis: calcd for C11H18O: C, 79.46; H, 10.91; found:
C, 79.47; H, 10.94.
(1) Synthesis of 2-methyl-2,3-octadienal (1c).27 Typical procedure
To a solution of oxalyl chloride (1.7 mL, d = 1.49, 2.53 g,
20.0 mmol) in anhydrous CH2C12 (35 mL) was slowly added
dropwise anhydrous DMSO (2.7 mL, d = 1.10, 2.97 g, 38.1 mmol)
at -78 ◦C with stirring under a nitrogen atmosphere. After being
stirred for 20 min at this temperature, a solution of 2-methyl-2,3-
octadienol (2.1 g, 15.0 mmol) in anhydrous CH2Cl2 (15 mL) was
added dropwise at -78 ◦C. After being stirred at -78 ◦C for an
additional 1.3 h, Et3N (10 mL, d = 0.73, 7.3 g, 72.3 mmol) was
added at this temperature. After removing the cooling bath, the
mixture was diluted with ether (40 mL) and washed with water
(30 mL ¥ 3). The ether layer was dried over anhydrous Na2SO4.
Evaporation and column chromatography on silica gel (petroleum
ether–ethyl acetate = 80 : l to 40 : 1) afforded 1c (1.66 g, 80%):
liquid, 1H NMR (300 MHz, CDCl3) d 9.50 (s, 1H), 5.71–5.61 (m,
1H), 2.15 (q, J = 7.2 Hz, 2H), 1.75 (d, J = 2.7 Hz, 3H), 1.50–1.29
(m, 4H), 0.90 (t, J = 7.0 Hz, 3H); 13C NMR (75 MHz, CDCl3) d
218.4, 192.9, 106.3, 95.5, 30.9, 27.5, 21.9, 13.7, 10.8; IR (neat), n
(cm-1) 2958, 2931, 2860, 1949, 1720, 1671, 1627, 1465, 1378, 1260,
1224; MS (70 ev, EI) m/z (%) 138 (M+, 1.05), 123 (M+ - CH3,
5.71), 95 (100); elemental analysis: calcd for C9H14O: C, 78.21; H,
10.21; found: C, 78.22; H, 10.20.
(5) Synthesis of 2,3-tetradecadienal (1f)
The reaction of n-butyl lithium (7.0 mL, 2.5 M in hexane,
17.5 mmol), 1,2-tridecadiene (3.40 g, 18.9 mmol), dimethylfor-
mamide (2.3 mL, d = 0.95, 2.19 g, 29.8 mmol), and anhydrous
THF (60 mL) afforded 1f (1.35 g, 37%): liquid, 1H NMR
(300 MHz, CDCl3) d 9.48 (d, J = 7.2 Hz, 1H), 5.85–5.70 (m,
2H), 2.18 (qd, J = 7.2, 3.0 Hz, 2H), 1.53–1.40 (m, 2H), 1.39–1.19
(m, 14H), 0.87 (t, J = 6.6 Hz, 3H); 13C NMR (75 MHz, CDCl3) d
219.1, 192.4, 98.6, 96.3, 31.9, 29.55, 29.53, 29.3, 28.9, 28.8, 27.5,
22.7, 14.1; IR (neat), n (cm-1) 2925, 2855, 1943, 1695, 1465, 1107,
1086; MS (70 ev, EI) m/z (%) 208 (M+, 3.40), 81 (100); elemental
The following compounds were prepared according to this proce-
dure.
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(2) Synthesis of 2-decyl-2,3-butadienal (1g)
Typical procedure for the zinc or indium mediated aqueous
allylation of 2,3-allenals.
The reaction of oxalyl chloride (1.05 mL, d = 1.49, 1.64 g,
12.4 mmol), anhydrous DMSO (1.8 mL, d = 1.10, 1.98 g,
25.4 mmol), 2-decyl-2,3-butadienol (1.60 g, 7.6 mmol), and Et3N
(7.0 mL, d = 0.73, 5.11 g, 50.6 mmol) in anhydrous CH2Cl2 (45 mL)
afforded 1g (1.35 g, 85%): liquid, 1H NMR (300 MHz, CDCl3) d
9.55 (s, 1H), 5.29 (t, J = 2.7 Hz, 2H), 2.20–2.10 (m, 2H), 1.48–1.35
(m, 2H), 1.34–1.17 (m, 14H), 0.86 (t, J = 6.8 Hz, 3H); 13C NMR
(75 MHz, CDCl3) d 222.3, 192.3, 110.9, 80.1, 31.9, 29.5, 29.32,
29.28, 29.2, 27.5, 24.1, 22.6, 14.1; IR (neat), n (cm-1) 2926, 2855,
2721, 1960, 1931, 1688, 1466, 1374, 1227, 1158; MS (70 ev, EI)
m/z (%) 208 (M+, 3.23), 109 (100); elemental analysis: calcd for
C14H24O: C, 80.71; H, 11.61; found: C, 80.68; H; 11.62.
(1) Synthesis of 1,1-pentamethylene-1,2,6-heptatrien-4-ol (2a)
Typical procedure for the reaction with indium
To a reaction vessel were added sequentially 1a (40 mg, 0.29 mmol),
an indium particle (with a size of ~0.5 mm (radius), 75 mg,
0.65 mmol), THF (0.8 mL), and saturated aqueous NH4Cl
(2.0 mL). To this mixture was then added allyl bromide (75 mg,
0.63 mmol) with vigorous stirring at rt. After 4.3 h with stirring
the reaction was complete as monitored by TLC. The mixture was
quenched with 10 mL of H2O, extracted with diethyl ether (30 mL ¥
2), washed with brine (20 mL), and dried over anhydrous Na2SO4.
Evaporation and column chromatography on silica gel (petroleum
ether–ethyl acetate = 5 : l) afforded 2a (49.6 mg, 95%): liquid,1H
NMR (400 MHz, CDCl3) d 5.89–5.76 (m, 1H), 5.20–5.03 (m, 3H),
4.14 (q, J = 6.0 Hz, 1H), 2.39–2.24 (m, 2H), 2.20–2.05 (m, 4H),
1.93 (s, 1H), 1.66–1.45 (m, 6H); 13C NMR (100 MHz, CDCl3) d
196.4, 134.4, 117.7, 106.2, 92.9, 69.2, 41.8, 31.5, 27.3, 25.9; IR
(neat), n (cm-1) 3354, 3076, 2927, 2854, 1966, 1641, 1447, 1436,
1345, 1264, 1058, 1024; MS (70 ev, EI) m/z (%) 178 (M+, 12.30),
67 (100); elemental analysis: calcd for C12H18O: C, 80.85; H, 10.18;
found: C, 80.86, H; 10.22.
(3) Synthesis of 2-heptyl-2,3-butadienal (1h)
The reaction of oxalyl chloride (0.48 g, 3.8 mmol), anhydrous
DMSO (0.55 mL, d = 1.10, 0.61 g, 7.5 mmol), 2-heptyl-2,3-
butadienol (0.51 g, 3.0 mmol), and Et3N (2.1 mL, d = 0.73, 1.53 g,
15.2 mmol) in anhydrous CH2Cl2 (18 mL) afforded 1h (0.37 g,
75%): liquid, 1H NMR (300 MHz, CDCl3) d 9.54 (s, 1H), 5.29 (t,
J = 2.6 Hz, 2H), 2.20–2.08 (m, 2H), 1.50–1.35 (m, 2H), 1.34–1.15
(m, 8H), 0.85 (t, J = 6.1 Hz, 3H); 13C NMR (75 MHz, CDCl3)
d 222.2, 192.2, 110.9, 80.1, 31.7, 29.1, 29.0, 27.5, 24.1, 22.6, 14.0;
IR (neat), n (cm-1) 2956, 2927, 2857, 2727, 1952, 1931, 1688, 1466,
1377, 1263, 1161, 1089, 1008; MS (70 ev, EI) m/z (%) 166 (M+,
0.65), 137 (M+ - CHO, 18.06), 95.1 (100); elemental analysis: calcd
for C11H18O: C, 79.46; H, 10.91; found: C, 79.50; H, 10.93.
The reaction of activated zinc powder (45 mg, 0.69 mmol), 1a
(41 mg, 0.30 mmol), allyl bromide (91 mg, 0.76 mmol), THF
(0.8 mL), and saturated aqueous NH4Cl (2.0 mL) at rt for 16 h
afforded 2a (43 mg, 80%).
The following compounds were prepared according to this proce-
dure.
(4) Synthesis of 2-allyl-butadienal (1i)
(2) Synthesis of 7-butyl-1,5,6-undecatrien-4-ol (2b)
The reaction of oxalyl chloride (1.4 mL, d = 1.49, 2.09 g,
16.6 mmol), anhydrous DMSO (2.4 mL, d = 1.10, 2.64 g,
33.8 mmol), 2-allylbutadienol (1.15 g, 10.5 mmol), and Et3N
(9.0 mL, d = 0.73, 6.57 g, 65.0 mmol) in anhydrous CH2Cl2 (20 mL)
afforded 1i (0.61 g, 54%): liquid, 1H NMR (300 MHz, CDCl3) d
9.57 (s, 1H), 5.87–5.71 (m, 1H), 5.34 (t, J = 2.9 Hz, 2H), 5.14–5.01
(m, 2H), 2.97–2.89 (m, 2H); 13C NMR (75 MHz, CDCl3) d 222.1,
191.5, 134.0, 116.7, 109.1, 80.8, 28.8; IR (neat), n (cm-1) 3065,
2985, 2917, 2828, 2729, 1959, 1931, 1683, 1642, 1428, 1229, 1165,
993, 920; MS (70 ev, EI) m/z (%) 108 (M+, 2.72), 107 (M+ - H,
25.17), 79 (M+ - CHO, 100); elemental analysis: calcd for C7H8O:
C, 77.75; H, 7.46; found: C, 77.60; H, 7.79.
The reaction of an indium particle (60 mg, 0.52 mmol), 1b (32 mg,
0.18 mmol), allyl bromide (49 mg, 0.41 mmol), THF (0.8 mL),
and saturated aqueous NH4Cl solution (2.0 mL) at rt for 7.5 h
afforded 2b (33.1 mg, 84%): liquid,1H NMR (300 MHz, CDCl3)
d 5.94–5.78 (m, 1H), 5.28–5.20 (m, 1H), 5.19–5.09 (m, 2H), 4.16
(q, J = 6.0 Hz, 1H), 2.42–2.24 (m, 2H), 2.02–1.90 (m, 4H), 1.70
(bs, 1H), 1.46–1.23 (m, 8H), 0.90 (t, J = 6.9 Hz, 6H); 13C NMR
(75 MHz, CDCl3) d 198.6, 134.5, 117.8, 108.6, 96.0, 69.3, 42.1,
32.2, 29.8, 22.4, 14.0; IR (neat), n (cm-1) 3384, 3077, 2958, 2930,
2860, 1962, 1641, 1466, 1378, 1026, 913; MS (70 ev, EI) m/z (%)
222 (M+, 14.60), 193 (M+ - C2H5, 10.97),179 (M+ - C3H7, 64.17),
95 (100); elemental analysis: calcd for C15H26O: C, 81.02; H, 11.79;
found: C, 81.01; H, 11.80.
(5) Synthesis of 2-propyl-4,4-pentamethylenebutadienal (1j)
The reaction of zinc powder (59 mg, 0.91 mmol), 1b (72 mg,
0.40 mmol), allyl bromide (144 mg, 1.20 mmol), THF (1.0 mL),
and saturated aqueous NH4Cl solution (2.6 mL) at rt for 13 h
afforded 2b (68.1 mg, 77%).
The reaction of oxalyl chloride (0.445 g, 3.5 mmol), anhydrous
DMSO (0.5 mL, d = 1.10, 0.550 g, 7.1 mmol), 2-propyl-4,4-
pentamethylenebutadienol (0.502 g, 2.8 mmol), and Et3N (1.9 mL,
d = 0.73, 1.39 g, 13.7 mmol) in anhydrous CH2Cl2 (18 mL) afforded
1
1j (0.404 g, 81%): liquid, H NMR (300 MHz, CDCl3) d 9.46 (s,
(3) Synthesis of 5-methyl-1,5,6-undecatrien-4-ol (2c)
1H), 2.24 (t, J = 6.0 Hz, 4H), 2.13 (t, J = 7.4 Hz, 2H), 1.75–1.55
(m, 6H), 1.49–1.37 (m, 2H), 0.91 (t, J = 7.4 Hz, 3H); 13C NMR
(75 MHz, CDCl3) d 213.4, 193.1, 109.7, 108.1, 30.6, 27.4, 26.8,
25.8, 20.9, 13.6; IR (neat), n (cm-1) 2932, 2856, 1946, 1682, 1446,
1261, 1216, 1181, 1105, 1019; MS (70 ev, EI) m/z (%) 178 (M+,
7.71), 149 (M+ - CHO, 73.17), 79 (100); elemental analysis: calcd
for C12H18O: C, 80.85; H, 10.18; found: C, 80.71; H, 10.33.
The reaction of an indium particle (119 mg, 1.03 mmol), 1c (55 mg,
0.40 mmol), allyl bromide (100 mg, 0.83 mmol), THF (0.8 mL),
and saturated aqueous NH4Cl solution (2.0 mL) at rt for 12 h
afforded 2c (46.8 mg, 65%): liquid, 1H NMR (300 MHz, CDCl3)
d 5.90–5.73 (m, 1H), 5.28–5.17 (m, 1H), 5.16–5.05 (m, 2H), 4.09–
3.98 (m, 1H), 2.46–2.35 (m, 1H), 2.32–2.19 (m, 1H), 1.98 (q,
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J = 6.9 Hz, 2H), 1.83 (bs, 1H), 1.70 (d, J = 2.7 Hz, 3H), 1.43–1.26
(m, 4H), 0.93–0.84 (m, 3H); IR (neat), n (cm-1) 3364, 3077, 2958,
2928, 2859, 1964, 1641, 1459, 1438, 1378, 1290, 1261, 1221, 1101,
1013, 992, 913; MS (70 ev, EI) m/z (%) 180 (M+, 0.23), 165 (M+ -
CH3, 8.19), 137 (M+ - C3H7, 24.99), 43 (100); elemental analysis:
calcd for C12H20O: C, 79.94; H, 11.18; found: C, 79.94; H, 11.17.
The reaction of zinc powder (55 mg, 0.84 mmol), 1c (55 mg,
0.40 mmol), allyl bromide (100 mg, 0.83 mmol), THF (0.8 mL),
and saturated aqueous NH4Cl solution (2.0 mL) at rt for 17 h
afforded 2c (41 mg, 57%).
30.7), 209 (M+ - C3H5, 24.8), 95 (100); elemental analysis: calcd
for C17H30O: C, 81.54; H, 12.08; found: C, 81.52; H, 12.13.
The reaction of zinc powder (60 mg, 0.92 mmol), 1f (61 mg,
0.29 mmol), allyl bromide (97 mg, 0.81 mmol), THF (0.8 mL),
and saturated aqueous NH4Cl solution (2.0 mL) at rt for 10 h
afforded 2f (58.6 mg, 80%).
(7) Synthesis of 3-decyl-1,2,6-heptatrien-4-ol (2g)
The reaction of an indium particle (80 mg, 0.69 mmol), 1g (62 mg,
0.30 mmol), allyl bromide (80 mg, 0.67 mmol), THF (0.8 mL),
and saturated aqueous NH4Cl solution (2.0 mL) at rt for 11 h
afforded 2g (62.9 mg, 84%): liquid, 1H NMR (300 MHz, CDCl3)
d 5.92–5.75 (m, 1H), 5.20–5.08 (m, 2H), 4.92–4.81 (m, 2H), 4.12–
4.02 (m, 1H), 2.49–2.37 (m, 1H), 2.36–2.24 (m, 1H), 2.08–1.89 (m,
2H), 1.75 (d, J = 5.7 Hz, 1H), 1.51–1.38 (m, 2H), 1.37–1.19 (m,
14H), 0.88 (t, J = 6.3 Hz, 3H); 13C NMR (75 MHz, CDCl3) d
204.4, 134.4, 117.9, 107.1, 78.8, 70.7, 40.1, 31.9, 29.6, 29.5, 29.4,
29.3, 28.2, 27.6, 22.7, 14.1; IR (neat), n (cm-1) 3374, 3077, 2925,
2854, 1955, 1641, 1466, 1378, 1035, 992, 913; MS (70 ev, EI) m/z
(%) 250 (M+, 1.2), 235 (M+ - CH3, 10.81), 221 (M+ - CHO, 6.04),
209 (M+ - C3H5, 17.96), 109 (100); elemental analysis: calcd for
C17H30O: C, 81.54; H, 12.08; found: C, 81.56; H, 12.09.
(4) Synthesis of 1-cyclohexyl-1,2,6-heptatrien-4-ol (2d)
The reaction of an indium particle (113 mg, 0.98 mmol), 1d
(74.5 mg, 0.50 mmol), allyl bromide (150 mg, 1.25 mmol), THF
(0.8 mL), and saturated aqueous NH4Cl solution (2.0 mL) at rt
for 26.3 h afforded 2d (82 mg, 86%): liquid, 1H NMR (400 MHz,
CDCl3) d 5.89–5.77 (m, 1H), 5.32–5.23 (m, 2H), 5.17–5.07 (m,
2H), 4.21–4.13 (m, 1H), 2.39–2.26 (m, 2H), 2.04–1.89 (m, 2H),
1.78–1.58 (m, 5H), 1.33–1.00 (m, 5H); IR (neat), n (cm-1) 3358,
3076, 2925, 2851, 1961, 1641, 1449, 1030, 994, 913; MS (70 ev,
EI) m/z (%) 192 (M+, 1.07), 151 (M+ - C3H5, 50.63), 91 (100);
elemental analysis: calcd for C13H20O: C, 81.20; H, 10.48; found:
C, 81.24; H, 10.44.
The reaction of zinc powder (40 mg, 0.61 mmol), 1g (62.1 mg,
0.30 mmol), allyl bromide (72.5 mg, 0.60 mmol), THF (0.8 mL),
and saturated aqueous NH4Cl solution (2.0 mL) at rt for 10 h
afforded 2g (39 mg, 84%).
The reaction of zinc powder (50 mg, 0.77 mmol), 1d (45.5 mg,
0.30 mmol), allyl bromide (80 mg, 0.67 mmol), THF (0.8 mL), and
saturated aqueous NH4Cl solution (2.0 mL) at rt for 27 h afforded
2d (43 mg, 74%).
(8) Synthesis of 3-heptyl-1,2,6-heptatrien-4-ol (2h)
The reaction of an indium particle (76 mg, 0.66 mmol), 1h (44 mg,
0.27 mmol), allyl bromide (80 mg, 0.67 mmol), THF (0.8 mL),
and saturated aqueous NH4Cl solution (2.0 mL) at rt for 10.3 h
afforded 2h (45 mg, 82%): liquid,1H NMR (300 MHz, CDCl3) d
5.91–5.74 (m, 1H), 5.19–5.07 (m, 2H), 4.93–4.81 (m, 2H), 4.13–
4.02 (m, 1H), 2.49–2.37, (m, 1H), 2.36–2.24 (m, 1H), 2.09–1.88
(m, 2H), 1.80 (bs, 1H), 1.53–1.38 (m, 2H), 1.37–1.17 (m, 8H), 0.87
(t, J = 6.3 Hz, 3H); 13C NMR (75 MHz, CDCl3) d 204.4, 134.4,
117.9, 107.1, 78.8, 70.7, 40.1, 31.8, 29.3, 29.1, 28.2, 27.6, 22.6, 14.1;
IR (neat), n (cm-1) 3355, 3077, 2927, 2856, 1956, 1641, 1466, 1435,
1374, 1206, 1028; MS (70 ev, EI) m/z (%) 208 (M+, 0.38), 207
(M+ - H, 0.40), 193 (M+ - CH3, 5.83), 167 (M+ - C3H5, 17.38), 83
(100); elemental analysis: calcd for C14H24O: C, 80.71; H, 11.61;
found: C, 80.78; H, 11.61.
(5) Synthesis of 1,5,6-tetradecatrien-4-ol (2e)
The reaction of an indium particle (100 mg, 0.87 mmol), 1e (67 mg,
0.40 mmol), allyl bromide (98 mg, 0.82 mmol), THF (0.8 mL), and
saturated aqueous NH4Cl solution (2.0 mL) at rt for 12 h afforded
1
2e (74.3 mg, 89%): liquid, H NMR (400 MHz, CDCl3) d 5.89–
5.78 (m, 1H), 5.33–5.26 (m, 1H), 5.25–5.19 (m, 1H), 5.17–5.08 (m,
2H), 4.22–4.14 (m, 1H), 2.40–2.26 (m, 2H), 2.05–1.96 (m, 2H),
1.96–1.86 (m, 1H), 1.45–1.35 (m, 2H), 1.34–1.19 (m, 8H), 0.87 (t,
J = 6.6 Hz, 3H); IR (neat), n (cm-1) 3353, 3077, 2957, 2926, 2855,
1963, 1641, 1467, 1437, 1378, 1029, 995, 913; MS (70 ev, EI) m/z
(%) 208 (M+, 0.49), 167 (M+ - C3H5, 11.57), 83 (100); elemental
analysis: calcd for C14H24O: C, 80.71; H, 11.61; found: C, 80.72;
H, 11.61.
The reaction of zinc powder (50 mg, 0.77 mmol), 1e (49 mg,
0.30 mmol), allyl bromide (80 mg, 0.67 mmol), THF (0.8 mL),
and saturated aqueous NH4Cl solution (2.0 mL) at rt for 10.4 h
afforded 2e (50 mg, 81%).
The reaction of zinc powder (40 mg, 0.61 mmol), 1h (45 mg,
0.27 mmol), allyl bromide (80 mg, 0.67 mmol), THF (0.8 mL),
and saturated aqueous NH4Cl solution (2.0 mL) at rt for 12 h
afforded 2h (49.6 mg, 88%).
(6) Synthesis of 1,5,6-heptadecatrien-4-ol (2f)
(9) Synthesis of 3-allyl-1,2,6-heptatrien-4-ol (2i)
The reaction of an indium particle (72 mg, 0.63 mmol), 1f (60.9 mg,
0.29 mmol), allyl bromide (90 mg, 0.75 mmol), THF (0.8 mL), and
saturated aqueous NH4Cl solution (2.0 mL) at rt for 10 h afforded
2f (62.4 mg, 85%): liquid, 1H NMR (400 MHz, CDCl3) d 5.91–5.78
(m, 1H), 5.35–5.27 (m, 1H), 5.26–5.20 (m, 1H), 5.19–5.10 (m, 2H),
4.22–4.15 (m, 1H), 2.43–2.27 (m, 2H), 2.06–1.97 (m, 2H), 1.82 (bs,
1H), 1.45–1.36 (m, 2H), 1.35–1.19 (m, 14H), 0.87 (t, J = 7.0 Hz,
3H); IR (neat), n (cm-1) 3361, 3077, 2925, 2854, 1963, 1647, 1467,
1027, 913; MS (70 ev, EI) m/z (%) 250 (M+, 14.6), 235 (M+ - CH3,
The reaction of an indium particle (92 mg, 0.80 mmol), 1i (43 mg,
0.40 mmol), allyl bromide (100 mg, 0.83 mmol), THF (1.0 mL),
and saturated aqueous NH4Cl solution (2.6 mL) at rt for 9.5 h
afforded 2i (43.6 mg, 73%): liquid,1H NMR (300 MHz, CDCl3)
d 5.87–5.68 (m, 2H), 5.14–4.95 (m, 4H), 4.85–4.75 (m, 2H), 4.11–
4.96 (m, 1H), 2.85–2.67 (m, 2H), 2.49 (s, 1H), 2.43–2.19 (m, 2H);
13C NMR (75 MHz, CDCl3) d 205.0, 135.5, 134.3, 118.0, 116.1,
105.1, 78.6, 70.4, 40.0, 33.3; IR (neat), n (cm-1) 3395, 3078, 2980,
2912, 1956, 1641, 1432, 1296, 1042; MS (70 ev, EI) m/z (%) 150
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(M+, 0.29), 149 (M+ - H, 2.38), 135 (M+ - CH3, 8.44), 109 (M+ -
C3H5, 77.94), 79 (100); elemental analysis: calcd for C10H14O: C,
79.96; H, 9.39; found: C, 79.94; H, 9.39.
The reaction of zinc powder (79.1 mg, 1.22 mmol), 1i (64.7 mg,
0.6 mmol), allyl bromide (144.1 mg, 1.19 mmol), THF (1.6 mL),
and saturated aqueous NH4Cl solution (4.0 mL) at rt for 17 h
afforded 2i (67.5 mg, 75%).
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(10) Synthesis of 1,1-pentamethylene-3-propyl-1,2,6-
heptatrien-4-ol (2j)
The reaction of an indium particle (125 mg, 1.09 mmol), 1j (61 mg,
0.34 mmol), allyl bromide (100 mg, 0.83 mmol), THF (1.0 mL),
and saturated aqueous NH4Cl solution (2.6 mL) at rt for 9.2 h
1
afforded 2j (54.3 mg, 72%): liquid, H NMR (300 MHz, CDCl3)
d 5.90–5.72 (m, 1H), 5.16–5.04 (m, 2H), 4.04–3.96 (m, 1H), 2.47–
2.33 (m, 1H), 2.32–2.18 (m, 1H), 2.17–2.04 (m, 4H), 1.93 (t, J =
7.0 Hz, 2H), 1.81 (s, 1H), 1.66–1.36 (m, 8H), 0.91 (t, J = 7.2 Hz,
3H); 13C NMR (75 MHz, CDCl3) d 193.0, 134.7, 117.2, 107.8,
105.5, 71.1, 40.2, 32.0, 31.9, 31.1, 27.84, 27.77, 26.1, 20.8, 13.8; IR
(neat), n (cm-1) 3387, 3076, 2928, 2854, 1961, 1641, 1445, 1377,
1335, 1262, 1028; MS (70 ev, EI) m/z (%) 220 (M+, 3.84), 191 (M+ -
C2H5, 6.57), 177 (M+ - C3H7, 100); elemental analysis: calcd for
C15H24O: C, 81.76; H, 10.98; found: C, 81.75; H, 10.97.
The reaction of zinc powder (40 mg, 0.61 mmol), 1j (52.9 mg,
0.30 mmol), allyl bromide (72.8 mg, 0.60 mmol), THF (0.8 mL),
and saturated aqueous NH4Cl solution (2.0 mL) at rt for 11 h
afforded 2j (45.2 mg, 69%).
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Acknowledgements
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65, 1736–1738.
Financial support from the National Natural Science Foundation
of China (20732005), the Major State Basic Research and De-
velopment Program (2006CB806105), and Cheung Kong Scholar
Program is greatly appreciated. Shengming Ma is a Qiu Shi
Adjunct Professor at Zhejiang University. We thank Mr. Guobi
Chai in this group for reproducing the results presented in entries
3–7 of Table 4.
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