Reduction of organic halides with tri-2-furylgermane: Stoichiometric and catalytic reduction

Article abstract of DOI:10.1246/bcsj.74.747

Tri-2-furylgermane proved to be an effective reagent for the radical reduction of organic halides. Treatment of 1-bromododecane with tri-2-furylgermane in THF at 25 °C in the presence of a catalytic amount of triethylborane afforded dodecane almost quantitatively. Radical cyclization of 2-iodoethanal allyl acetal afforded five-membered products under the same reaction conditions. These reactions proceeded with NaBH₄ in the presence of a catalytic amount of germanium hydride. The reaction took place in water as well as in THF to give the corresponding reduced compounds in good yields.

Full text of DOI:10.1246/bcsj.74.747

c. Jpn.
e Chemical © 2001 The Chemical Society of Japan
Bull. Chem. Soc. Jpn., 74, 747—752 (2001)
747
ciety of Ja-
n
e Chemical
ciety of Ja-
n
Reduction of Organic Halides with Tri-2-furylgermane: Stoichiometric
and Catalytic Reduction
Reduction with Tri-2-furylgermane
T. Nakamura et al.
Tomoaki Nakamura, Hideki Yorimitsu, Hiroshi Shinokubo, and Koichiro Oshima*
0
7
2
1
Department of Material Chemistry, Graduate School of Engineering, Kyoto University,
Yoshida, Sakyo-ku, Kyoto 606-8501
SJA8
09-2673
(
Received November 6, 2000)
382
vember
Tri-2-furylgermane proved to be an effective reagent for the radical reduction of organic halides. Treatment of
00
1-bromododecane with tri-2-furylgermane in THF at 25 ˚C in the presence of a catalytic amount of triethylborane afford-
ed dodecane almost quantitatively. Radical cyclization of 2-iodoethanal allyl acetal afforded five-membered products
4
under the same reaction conditions. These reactions proceeded with NaBH in the presence of a catalytic amount of ger-
00
manium hydride. The reaction took place in water as well as in THF to give the corresponding reduced compounds in
good yields.
0.2
Reduction of organic halide into the corresponding hydro-
carbon is one of the most important reactions in organic syn-
Table 1.
with Tri-2-furylgermane
Stoichiometric Reduction of Organic Halides
1
thesis. Among many reagents employed for this purpose, tri-
2
alkyltin hydride is the most reliable one and has been widely
used, although its toxicity is a drawback. Very recentry, many
efforts to solve this problem have been made and new com-
3
pounds such as tris(trimethylsilyl)silane have been developed
Entry
RX
Time/h
Yield/%
to replace trialkyltin hydride. Here we wish to report an alter-
native solution. The reduction of organic halide with tri-2-fu-
rylgermane or triphenylgermane proceeds effectively in the
1
2
3
4
n-C12
n-C12
H
25
I
1
2
6
2.5
99
99
99
83
H
25Br
n-C H CH(Br)CH
3
1
0
21
4
presence of triethylborane as a radical initiator. The reduction
1-Bromoadamantane
of organic halides with tri-2-furylgermane in water is also de-
scribed.
5
5
6
2
2
99
99
(1) Stoichiometric and Catalytic Reduction of Organic
Halides in THF
The reduction of various organic halides using tri-2-fu-
rylgermane (1) was examined. The reduction of organic ha-
6
a)
7
8
1.5
1
93
lides with 1 completed smoothly in the presence of triethylbo-
rane at room temperature in THF. The representative results
are shown in Table 1. Iodides and bromides were reduced ef-
fectively to give the corresponding hydrocarbons in excellent
yields. In contrast, chloride such as 1-chlorododecane was re-
covered unchanged. Barton deoxygenation was also success-
ful (Entry 8).
80
a) Tri-2-furylgermane (1.5 mmol) was used.
GeH (4) or n-Bu GeH (5) has been reported. However,
7
Ph
3
3
Next, the radical cyclization reaction of 2-iodoethanal allyl
acetal was studied. Triethylborane (0.20 mmol) was added to a
solution of β-iodo acetal 2a (1.0 mmol) and tri-2-furylgermane
few examples of catalytic reduction with germanium hydride
are known. Thus, we examined the catalytic reaction. The
Et B-induced reduction of 1-iodododecane with NaBH (2.0
3 4
mmol) in the presence of a catalytic amount of 1 (0.10 mmol)
8
(
1, 1.2 mmol) in THF (10 mL) at 25 ˚C. The resulting mixture
was stirred for 15 min. Concentration followed by silica-gel
column purification afforded tetrahydrofuran derivative 3a in
in THF proceeded easily to give dodecane almost quantitative-
9
ly. The results of the reaction with three germanium hydrides :
97% yield. Table 2 summarizes the results. Not only iodo ac-
1, 4, and 5, are shown in Table 3. Several comments are worth
noting. (1) Catalytic reduction was examined in several sol-
vents such as ethanol, hexane, THF, and acetonitrile. Among
them, THF gave the best result. (2) Not only primary halides
(1-iodododecane and 1-bromododecane), but also secondary
and tertiary halides such as 2-bromododecane and 1-bromoad-
amantane were reduced to the corresponding alkanes in good
etals, generated by iodoetherization of alkenyl ethers with al-
lylic alcohol and N-iodosuccinimide, but also bromo acetal 2d
and the allylic ethers of o-iodophenol 2e and 2f reacted easily
with tri-2-furylgermane to give the corresponding cyclic prod-
ucts.
The stoichiometric reduction of organic halides with

7
48 Bull. Chem. Soc. Jpn., 74, No. 4 (2001)
Reduction with Tri-2-furylgermane
Table 2.
Entry
Radical Cyclization with Tri-2-furylgermane
Substrate
Time/h
Product
Yield/%
9
7
1
0.25
(
84/16)
6
3
2
3
1.5
0.5
(
(
56/44)
quant
64/36)
8
1
4
5
6
1.5
2
(
62/38)
89
1.5
88
Table 3.
Germanium Hydride-Catalyzed Reduction of Organic Halides
Entry
1
RX
R′
3
GeH
Time/h
4
Yield/%
98
n-C12
H
25
I
2
3
4
5
6
7
8
9
n-C12
n-C12
n-C12
H
H
H
25Br
25Br
25Cl
25
25
25
I
I
I
Ph
n-Bu
3
GeH
4
4
6
4
98
89
98
95
89
3
GeH 5
1
4
5
1
4
4
1
1
1
n-C12
n-C12
n-C12
H
H
H
4
12
24
5
10
4
a)
5
n-C10
H
21CH(Br)CH
1-Bromoadamantane
PhCOO(CH Br
I(CH OTHP
o-I-C CH OH
3
89
73
90
97
77
1
1
1
0
1
2
2 3
)
2
)
6
1
7
b)
6
H
4
2
a) Starting material (95%) was recovered. b) AIBN (0.20 mmol) was used instead of
Et B and NaBH (4.0 mmol) was employed. The reaction was performed at reflux in
THF.
3
4
yields. (3) Many functional groups such as ester and THP
ether could survive under the reaction conditions. (4) Al-
though alkyl iodide and bromide were easily reduced to the
corresponding alkanes, alkyl chloride was recovered almost
unchanged. (5) The amount of the catalyst could be reduced to
acetal 6a (1.0 mmol) with Ph
mL) in the presence of NaBH
mmol) gave 7a in 75% yield. Allyl β-iodoalkyl ether 6b, 6-
bromo-1-dodecene (8a), and 6-iodo-1-dodecene (8b) also gave
the corresponding cyclization products, 7b and 9, in 56%,
73%, and 71% yields, respectively (Scheme 1). In these reac-
tions, Ph GeH gave better yields than tri-2-furylgermane (1).
3
For instance, the use of 1 in the reaction of 6b provided 7b in
only 20% yield.
3
GeH (4, 0.10 mmol) in THF (10
(2.0 mmol) and Et B (0.20
4
3
2
mol% without decrease of the yield of the product. For in-
stance, treatment of 1-iodododecane (1.0 mmol) with NaBH
2.0 mmol) at 25 ˚C for 12 h in the presence of 1 (0.02 mmol)
provided dodecane in 96% yield.
4
(
The germanium hydride-induced radical cyclization reac-
tion also took place in a catalytic manner. Treatment of β-iodo
(2) Reduction of Organic Halides with Tri-2-furylger-
mane in Water

T. Nakamura et al.
Bull. Chem. Soc. Jpn., 74, No. 4 (2001) 749
8
1% yield (Table 4).
We, then studied the triethylborane-induced radical reduc-
tion of several organic halides with tri-2-furylgermane in wa-
ter. Four examples are shown in Table 5. The secondary and
tertiary alkyl halides as well as primary ones were easily re-
duced to the corresponding hydrocarbons in excellent yields.
Ph
water. For example, treatment of 1-bromododecane with
Ph GeH in water afforded dodecane in 80% yield along with
the starting material (8%). Thus, tri-2-furylgermane is more
effective than Ph GeH.
Next, the reduction using V-70 [2,2′-azobis(4-methoxy-2,4-
3
GeH is also effective for the reduction of organic halides in
3
3
Scheme 1.
1
3
dimethylvaleronitrile)] as a radical initiator instead of trieth-
ylborane was examined in order to eliminate the effect of alco-
hol such as methanol or ethanol which was used to obtain a so-
Recently, there has been increasing recognition that organic
reactions carried out in aqueous media or in water may offer
advantages over those occurring in organic solvents. For in-
stance, it was reported that the Diels–Alder reaction was accel-
1
4
lution of triethylborane. V-70 was added to a suspension of
organic halide and tri-2-furylgermane in water and the whole
mixture was stirred at 80 ˚C for 20 min ꢀ 4.5 h. The represen-
tative results are shown in Table 6. All organic halides exam-
ined were converted into the corresponding reduction products
in good to excellent yields, irrespective of the solubility to wa-
ter. The functional groups such as ester and THP ether sur-
vived under the reaction conditions.
1
0,11
erated by using water as a solvent.
facile atom-transfer cyclization of allyl iodoacetate mediated
We also reported the
1
2
by triethylborane in water. Here we describe the results of
the reduction of organic halides with tri-2-furylgermane in wa-
ter.
First, the reduction of 1-bromododecane with tri-2-furylger-
mane in various solvents was examined. Treatment of 1-bro-
mododecane (1.0 mmol) with tri-2-furylgermane (1.2 mmol)
in the presence of triethylborane (1.0 M hexane solution, 0.20
mL, 0.20 mmol) at 25 ˚C for 20 min gave dodecane in 90%
Finally, the one-pot conversion of allylic iodoacetates into γ-
lactones was examined. Triethylborane was added to a suspen-
sion of allyl iodoacetate 10a in water and the mixture was
stirred at 25 ˚C for 1.5 h to give β-iodomethyl-γ-butyrolactone.
Then, tri-2-furylgermane was subsequently added to the result-
ing solution of the β-iodomethyl-γ-butyrolactone and the
whole was stirred for another 5 h to give γ-lactone 11a in 56%
overall yield (Scheme 2). In a similar fashion, β-propyl-γ-bu-
tyrolactone was obtained in 67% yield starting from 10b.
In conclusion, (1) Triethylborane-induced radical reduction
of organic halides with tri-2-furylgermane in THF proceeded
very easily to give the corresponding reduced compounds in
good to excellent yields. (2) Radical cyclization of 2-haloetha-
nal allyl acetal afforded five-membered products under the
same reaction conditions. (3) The reduction completed with
(
THF), 74% (benzene), 44% (hexane), and 87% (water) yields,
respectively. Without a solvent, dodecane was obtained in
Table 4. Reduction of 1-Bromododecane in Various
Solvents
n
Entry
Solvent
Yield/%
C
12
H25–Br/%
NaBH
4
in the presence of a catalytic amount of germanium hy-
GeH, or n-Bu GeH). (4) Water
1
2
3
THF
benzene
hexane
H O
2
neat
90
74
44
87
81
5
dride (tri-2-furylgermane, Ph
3
3
19
51
6
could be used as a solution in place of THF. The acceleration
of the reaction could not be observed by using water as a sol-
vent in this radical reduction of organic halides. Treatment of
a)
4
5
9
1
-bromododecane with tri-2-furylgermane without a solvent
3
a) A methanol solution of Et B (1.0 M, 0.10 mL, 0.10
provided dodecane in 81% yield, which is similar to the results
mmol) was used.
Table 5.
Reduction of Organic Halides with Tri-2-
furylgermane in Water Using Triethylborane as an Initiator
Entry
RX
Time/min
Yield/%
1
2
3
4
n-C12
n-C12
n-C10 21CH(Br)CH
1-Bromoadamantane
H
25
I
5
25
15
20
85
89
83
92
H
25Br
H
3
Scheme 2.

7
50 Bull. Chem. Soc. Jpn., 74, No. 4 (2001)
Reduction with Tri-2-furylgermane
Table 6. V-70 Mediated Reduction of Organic Halides with Tri-2-furylgermane in Water
Entry
RX
Time/h
Yield/%
1
2
3
4
5
6
n-C12
n-C12
n-C10 21CH(Br)CH
1-Bromoadamantane
PhCOO(CH Br
I(CH OTHP
H
25
I
0.5
0.5
0.33
1
1
0.25
80
83
82
92
99
88
H25Br
H
3
2
)
3
2
)
6
7
0.5
63
97
8
9
HO(CH
2
CH
2
O)
3
CH
2
CH
2
I
1
3.5
6
8
(cis/trans ꢂ 70/30)
1
0
4.5
7
5
1
3
in THF and in water. The reaction rates were almost the same
in water, in THF, and without a solvent. Thus, in a small scale
reaction, a solvent-free reaction is recommended. In contrast,
the use of water as a solvent would be favorable in order to
suppress the heat of an exothermic reaction. (5) Direct conver-
sion of allyl iodoacetate into γ-butyrolactone could be per-
formed by sequential treatment with triethylborane and tri-2-
furylgermane in water.
ꢂ 3.3 Hz, 3H), 7.73 (d, J ꢂ 1.5 Hz, 3H); C NMR (CDCl
110.01, 121.86, 147.74, 150.59. Found: C, 52.18; H, 3.78%. Cal-
cd for C12 : C, 52.45; H, 3.67%.
3
) δ
H10GeO
3
General Procedure for the Stoichiometric Reduction of Or-
ganic Halides in THF. Reduction of 1-bromododecane is repre-
sentative. A hexane solution of Et B (1.0 M, 0.10 mL, 0.10 mmol)
3
was added to a solution of 1-bromododecane (0.25 g, 1.0 mmol)
and tri-2-furylgermane (0.33 g, 1.2 mmol) in THF (10 mL) at
room temperature under an argon atmosphere. After stirring for 2
h at room temperature, the reaction mixture was concentrated in
vacuo. The residual oil was subjected to silica-gel column chro-
matography to give dodecane in 99% yield.
The Catalytic Reduction of Organic Halides in THF.
typical procedure is as follows. Et B (1.0 M hexane solution, 0.10
mL, 0.10 mmol) and NaBH (0.076 g, 2.0 mmol) were added to a
solution of 1-bromododecane (0.25 g, 1.0 mmol) and tri-2-fu-
rylgermane (0.027 g, 0.10 mmol) in THF (10 mL) at room temper-
ature under an argon atmosphere. After stirring for 4 h at room
temperature, the reaction mixture was poured into aqueous HCl (1
M) and extracted with hexane three times. Combined organic lay-
ers were washed with brine, dried over Na SO , and concentrated
2 4
in vacuo. The residual oil was subjected to silica-gel column
chromatography to give dodecane in 98% yield.
The Reduction of Organic Halides in the Presence of V-70 in
Water. V-70 (0.015 g, 0.050 mmol) was added to a suspension
of 1-bromododecane (0.12 g, 0.50 mmol) and tri-2-furylgermane
Experimental
1
13
The NMR spectra ( H and C) were recorded on a Varian
GEMINI 300 spectrometer in CDCl ; tetramethylsilane (TMS)
3
A
was used as an internal standard. The IR spectra were determined
on a JASCO IR-810 spectrometer. The analyses were carried out
at the Elemental Analysis Center of Kyoto University.
Synthesis of Tri-2-furylgermane. Butyllithium (250 mL, 1.6
M hexane solution, 400 mmol) was added to a solution of furan
3
4
(
30.0 g, 400 mmol) in THF (250 mL) at 0 ˚C. The solution imme-
diately turned yellow and the resulting mixture was stirred for 30
min at 0 ˚C. Then a solution of germanium tetrachloride (11 mL,
9
0 mmol) in benzene (80 mL) was added at 0 ˚C and the solution
was stirred for another 3 h at 25 ˚C. The mixture was poured into
water and extracted with ethyl acetate (50 mLꢀ3). The combined
organic layer was dried and concentrated in vacuo to give a solid.
Recrystallization from toluene provided tetra-2-furylgermane (26
g, 77 mmol) in 85% yield. Lithium metal (0.830 g, 120 mmol)
was added to a solution of tetra-2-furylgermane (10 g, 30 mmol)
in THF (30 mL) and the resulting mixture was stirred for 1.5 h at
(
0.16 g, 0.60 mmol) in water (5 mL) at room temperature under an
argon atmosphere. The mixture was heated at 80 ˚C for 30 min.
The reaction mixture was extracted with hexane three times.
Evaporation of the solvent and purification gave dodecane in 83%
yield.
Cyclization of Allyl Iodoacetate in Water.
methanol solution, 0.1 mL, 0.1 mmol) was added to a suspension
2
5 ˚C. Extractive workup (EtOAc, brine) followed by silica-gel
column purification gave tri-2-furylgermane (1, 5.8 g, 21 mmol) in
7
1
0% yield. 1: IR (neat) 2086, 1551, 1454, 1362, 1206, 1151,
ꢁ
1
1
3
Et B (1.0 M
103, 1062, 1004, 898, 884, 819, 741, 594 cm
; H NMR
(
CDCl
3
) δ 5.78 (s, 1H), 6.47 (dd, J ꢂ 3.3, 1.5 Hz, 3H), 6.81 (d, J

T. Nakamura et al.
Bull. Chem. Soc. Jpn., 74, No. 4 (2001) 751
of allyl iodoacetate (0.22 g, 1.0 mmol) in water (50 mL) at room
temperature under an argon atmosphere and the mixture was
stirred for 1.5 h. Tri-2-furylgermane (0.33 g, 1.2 mmol) was add-
ed and the whole was stirred for another 5 h. The reaction mixture
was extracted with ethyl acetate three times and the organic layer
was concentrated. Silica-gel column purification of the crude
product provided β-methyl-γ-butyrolactone 11a in 56% yield.
Characterization Data. Spectral data for the compounds
39.89, 40.08, 40.60, 114.96, 138.37. Found: C, 49.24; H, 8.01%.
Calcd for C12
H23I: C, 48.99; H, 7.88%.
1-Hexyl-2-methylcyclopentane (9, Mixture of Diastere-
ꢁ
1 1
omers, 76/24). IR (neat) 2920, 2854, 1458, 1377, 722 cm ; H
NMR (CDCl ) δ 0.77 (d, J ꢂ 6.9 Hz, 0.76ꢀ3H), 0.88 (t, J ꢂ
6.9Hz, 3H), 0.95 (d, J ꢂ 6.3 Hz, 0.24ꢀ3H), 1.00–1.88 (m, 0.76 ꢀ
3
13
3
17H ꢃ 0.24 ꢀ 18H), 1.90–2.05 (m, 0.76H); C NMR (CDCl ):
For major isomer, δ 14.01, 14.67, 22.41, 22.63, 28.73, 29.67,
29.71, 30.46, 31.90, 33.49, 35.90, 43.33. Found: C, 85.68; H,
14.58. Calcd for C12H24: C, 85.63; H, 14.37%.
1
2,15
2
b–f, 3b–f, 7, 10, and 11 are found in the literature.
-Iodo-2-(2-hexenyloxy)tetrahydropyran (2a).
912, 2846, 1672, 1463, 1436, 1354, 1303, 1202, 1122, 1068,
3
IR (neat)
2
8
ꢁ
1 1
66, 695 cm ; H NMR (CDCl
3
) δ 0.89 (t, J ꢂ 7.2 Hz, 3H), 1.42
This work was suported by Grants-in Aid for Scientific Re-
search (Nos. 12305058 and 10208208) from the Ministry of
Education, Science, Sports and Culture. T. N. and H. Y. ac-
knowledge the JSPS Research Fellowship for Young Scientists
for financial support. H. S. also thanks Banyu Pharmaceutical
Co., Ltd.
(
tq, J ꢂ 7.2, 7.2 Hz, 2H), 1.50–1.61 (m, 1H), 1.69–1.80 (m, 1H),
1
1
4
1
1
1
1
.94–2.04 (m, 1H), 2.02 (dt, J ꢂ 6.6, 7.2 Hz, 2H), 2.31–2.41 (m,
H), 3.56 (ddd, J ꢂ 11.7, 7.8, 3.9 Hz, 1H), 3.93–4.00 (m, 2H),
.09 (ddd, J ꢂ 8.1, 4.5, 4.5 Hz, 1H), 4.18 (dd, J ꢂ 11.7, 6.6 Hz,
H), 4.66 (d, J ꢂ 4.5 Hz, 1H), 5.56 (ddd, J ꢂ 15.3, 6.6, 6.6 Hz,
1
3
H), 5.71 (ddd, J ꢂ 15.3, 6.6, 6.6 Hz, 1H); C NMR (CDCl
3.55, 22.03, 25.40, 29.39, 32.61, 34.24, 63.35, 68.85, 101.27,
25.56, 135.38. Found: C, 42.45; H, 6.04%. Calcd for C11
3
) δ
H19IO :
2
References
C, 42.60; H, 6.17%.
-Butyl-2,9-dioxabicyclo[4.3.0]nonane (3a, Mixture of Dias-
tereomers, 84/16). IR (neat) 2924, 2856, 1724, 1467, 1403,
7
1
“Comprehensive Organic Synthesis,” ed by B. M. Trost, I.
Fleming, and C. H. Heathcock, Pergamon Press, Oxford (1991),
Vol. 8, Chap. 4.
ꢁ
1 1
1
0
2
3
253, 1146, 1090, 1023, 949, 902, 870 cm ; H NMR (CDCl ) δ
.90 (t, J ꢂ 6.9 Hz, 3H), 1.10–1.45 (m, 7H), 1.54–1.98 (m, 4H),
.25–2.37 (m, 1H), 3.42 (ddd, J ꢂ 11.4, 11.4, 1.8 Hz, 0.16H), 3.54
2
a) D. P. Curran, Synthesis, 1988, 417, 489. b) A. G. Davis,
“Organotin Chemistry,” WILEY-VCH, Weinheim (1997).
a) C. Chatgilialoglu, D. Griller, and M. Lesage, J. Org.
(
(
dd, J ꢂ 8.4, 8.4 Hz, 0.16H), 3.60–3.69 (m, 0.84ꢀ2H), 3.70–3.80
m, 0.84H), 3.80–3.94 (m, 0.16H), 3.95 (dd, J ꢂ 8.1, 8.1 Hz,
3
Chem., 53, 3641 (1988). b) C. Chatgilialoglu, Acc. Chem. Res.,
25, 188 (1992). c) B. Giese, B. Kopping, and C. Chatgilialoglu,
Tetrahedron Lett., 30, 681 (1989).
0
0
.84H), 4.28 (dd, J ꢂ 8.4, 8.4 Hz, 0.16H), 5.00 (d, J ꢂ 3.6 Hz,
.16H), 5.28 (d, J ꢂ 3.6 Hz, 0.84H); C NMR (CDCl ): For ma-
3
1
3
jor isomer, δ 13.83, 19.05, 22.74, 23.12, 26.55, 30.35, 36.41,
4
a) K. Nozaki, K. Oshima, and K. Utimoto, J. Am. Chem.
4
0.91, 60.89, 70.12, 102.06. For minor isomer: δ 13.83, 20.61,
Soc., 109, 2547 (1987). b) Y. Ichinose, K. Nozaki, K. Wakamatsu,
K. Oshima, and K. Utimoto, Tetrahedron Lett., 28, 3709 (1987).
2
2.30, 22.78, 30.62, 32.32, 37.74, 44.06, 64.42, 74.26, 102.06.
Found: C, 71.57; H, 11.21%. Calcd for C11
0.94%.
-Iodo-1-methoxy-1-(2-propenyloxy)decane (6a, Mixture of
Diastereomers, 80/20). IR (neat) 2922, 2850, 1459, 1102, 1048,
H
20
O
2
: C, 71.70; H,
5
A part of this work was communicated: T. Nakamura, H.
Yorimitsu, H. Shinokubo, and K. Oshima, Synlett, 1999, 1415.
Synthesis of tri-2-furylgermane from germanium bromide
in the solid LiAlH /hydrocarbon system has been reported. V. N.
1
2
6
4
ꢁ
1 1
9
25 cm ; H NMR (CDCl
3
): For major isomer, δ 0.86 (t, J ꢂ 6.6
Gevorgyan, L. M. Ignatovich, and E. Lukevics, J. Organomet.
Chem., 284, C31 (1985). However, no reaction with tri-2-fu-
rylgermane has been reported.
Hz, 3H), 1.12–1.42 (m, 11H), 1.42–1.66 (m, 1H), 1.76 (dt, J ꢂ
7
6
.2, 6.9 Hz, 2H), 3.39 (s, 3H), 4.03–4.13 (m, 1H), 4.06 (dt, J ꢂ
.9, 7.2 Hz, 1H), 4.18 (dd, J ꢂ 5.4, 12.9 Hz, 1H), 4.36 (d, J ꢂ 5.4
7
a) K. U. Ingold, J. Lusztyk, and J. C. Scaiano, J. Am. Chem.
Hz, 1H), 5.19 (d, J ꢂ 10.5 Hz, 1H), 5.27 (d, J ꢂ 17.1 Hz, 1H),
Soc., 106, 343 (1984). b) A. L. J. Beckwith and C. H. Schiesser,
Tetrahedron, 41, 3925 (1985). c) P. Pike, S. Hershberger, and J.
Hershberger, Tetrahedron, 44, 6295 (1988).
1
3
5
.92 (ddt, J ꢂ 10.5, 17.1, 5.4 Hz, 1H); C NMR (CDCl
3
): For ma-
jor isomer, δ 13.95, 22.51, 28.69, 29.10, 29.25, 29.31, 31.71,
3
4
3.82, 36.54, 54.69, 68.76, 105.18, 117.45, 134.09. Found: C,
7.37; H, 7.76%. Calcd for C14 : C, 47.46; H, 7.68%.
-Iodo-1-(2-propenyloxy)decane (6b). IR (neat) 2922,
8
Only one example can be found in the literature. V. Gupta
and D. Kahne, Tetrahedron Lett., 34, 591 (1993).
The corresponding germanium halides could be employed
H27IO
2
2
9
ꢁ
1 1
2
852, 1460, 1381, 1349, 1073, 993, 925 cm ; H NMR (CDCl
3
)
in the catalytic reaction in place of germanium hydrides. Howev-
er, we preferred to use germanium hydrides because of their sta-
bility and easy handling.
10 a) D. C. Rideout and R. Breslow, J. Am. Chem. Soc., 102,
7816 (1980). b) P. A. Grieco, K. Yoshida, and P. Garner, J. Org.
Chem., 48, 3137 (1983).
11 a) A. Lubineau, J. Auge, and Y. Queneau, Synthesis, 1994,
741. b) “Organic Reactions in Aqueous Media,” ed by C.-J. Li,
and T.-H. Chan, WILEY, NewYork (1997). c) “Organic Reactions
in Water,” ed by P. Grieco, Blackie Academic & Professional,
London (1998).
δ 0.86 (t, J ꢂ 6.6 Hz, 3H), 1.18–1.42 (m, 11H), 1.44–1.59 (m,
H), 1.67–1.87 (m, 2H), 3.60 (dd, J ꢂ 10.2, 7.4 Hz, 1H), 3.70 (dd,
J ꢂ 10.2, 6.0 Hz, 1H), 4.01 (d, J ꢂ 5.4 Hz, 2H), 4.10–4.19 (m,
1
1
H), 5.18 (dd, J ꢂ 10.5, 1.7 Hz, 1H), 5.27 (dd, J ꢂ 17.1, 1.7 Hz,
13
1
H), 5.89 (dddd, J ꢂ 17.1, 10.5, 7.4, 6.0 Hz, 1H); C NMR
) δ 13.98, 22.54, 28.74, 29.13, 29.22, 29.29, 31.74, 34.28,
6.43, 71.85, 75.79, 117.44, 134.52. Found: C, 48.36; H, 7.49%.
25IO: C, 48.16; H, 7.77%.
-Iodo-1-dodecene (8b). IR (neat) 2924, 2854, 1642, 1378,
(
CDCl
3
3
Calcd for C13
H
6
ꢁ
1 1
1
213, 992, 912, 723 cm ; H NMR (CDCl
Hz, 3H), 1.20–1.78 (m, 12H), 1.78–1.94 (m, 2H), 1.98–2.16 (m,
H), 4.12 (tt, J ꢂ 4.5, 8.4 Hz, 1H), 4.97 (d, J ꢂ 10.5 Hz, 1H), 5.01
3
) δ 0.88 (t, J ꢂ 6.9
12 H. Yorimitsu, T. Nakamura, H. Shinokubo, and K. Oshima,
J. Org. Chem., 63, 8604 (1998).
13 Y. Kita, A. Sano, T. Yamaguchi, M. Oka, K. Gotanda, and
M. Matsugi, J. Org. Chem., 64, 675 (1999).
2
13
(
d, J ꢂ 17.1 Hz, 1H), 5.80 (ddt, J ꢂ 10.5, 17.1, 6.6 Hz, 1H);
C
NMR (CDCl ) δ 13.93, 22.48, 28.40, 28.63, 29.37, 31.57, 32.80,
3

7
52 Bull. Chem. Soc. Jpn., 74, No. 4 (2001)
An attempt to prepare an aqueous solution of Et
Reduction with Tri-2-furylgermane
1
4
3
B resulted
Chem. Soc. Jpn., 70, 2039 (1997). b) A. Inoue, H. Shinokubo, and
K. Oshima, Org. Lett., 2, 651 (2000). c) D. P. Curran and M. J.
Totleben, J. Am. Chem. Soc., 114, 6050 (1992).
in failure. Triethylborane did not dissolve in water and floated on
the water.
1
5
a) R. Inoue, J. Nakao, H. Shinokubo, and K. Oshima, Bull.