Reductive ring-opening reaction of 2,3-epoxy-1,4-butanediones with SbCl3-Bu4NI in the presence of Na2S 2O3·5H2O

Article abstract of DOI:10.1080/00397910500180121

1,4-Disubstituted 2,3-epoxy-1,4-butanediones were converted to 1,4-disubstituted 2-hydroxy-1,4-butanediones with SbCl₃-Bu ₄NI in the presence of Na₂S₂O ₃-5H₂O. The ring opening of terminal epoxides can also be accomplished to afford the corresponding haloalcohol with SbCl₃ and tetrabutylammonium halides, Bu₄NX (X = Cl, Br, I) under the same reaction conditions. Copyright Taylor & Francis, Inc.

Full text of DOI:10.1080/00397910500180121

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Reductive Ring‐Opening
Reaction of
2,3‐Epoxy‐1,4‐butanediones
with SbCl3‐Bu4NI in the
Presence of Na2S2O3·5H2O
Shinsei Sayama a
a Department of Chemistry, Fukushima Medical
University, Hikariga‐oka, Fukushima, Japan
Published online: 18 Aug 2006.
To cite this article: Shinsei Sayama (2005) Reductive Ring‐Opening Reaction of
2,3‐Epoxy‐1,4‐butanediones with SbCl3‐Bu4NI in the Presence of Na2S2O3·5H2O,
Synthetic Communications: An International Journal for Rapid Communication of
Synthetic Organic Chemistry, 35:16, 2115-2124
To link to this article: http://dx.doi.org/10.1080/00397910500180121
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Synthetic Communicationsw, 35: 2115–2124, 2005
Copyright # Taylor & Francis, Inc.
ISSN 0039-7911 print/1532-2432 online
DOI: 10.1080/00397910500180121
Reductive Ring-Opening Reaction
of 2,3-Epoxy-1,4-butanediones with
SbCl3-Bu4NI in the Presence
.
of Na2S2O3 5H2O
Shinsei Sayama
Department of Chemistry, Fukushima Medical University, Hikariga-oka,
Fukushima, Japan
Abstract: 1,4-Disubstituted 2,3-epoxy-1,4-butanediones were converted to 1,4-
disubstituted 2-hydroxy-1,4-butanediones with SbCl3-Bu4NI in the presence of
.
Na2S2O3 5H2O. The ring opening of terminal epoxides can also be accomplished to
afford the corresponding haloalcohol with SbCl3 and tetrabutylammonium halides,
Bu4NX (X ¼ Cl, Br, I) under the same reaction conditions.
Keywords: Antimony(III) chloride, 2,3-epoxy-1,4-butanedione, haloalcohol, tetra-
butylammonium halide
Epoxides have been recognized as important intermediates in organic
synthesis. In particular, the ring-opening of epoxides is a key reaction for
the synthesis of marine natural products containing haloalcohol and poly-
alcohol moieties.[1] Therefore, regio- and stereoselective ring-opening
reactions of epoxides were accomplished with various reagents and are still
considered an intriguing study area.[1–4]
A variety of reductive reagents, such as LiAlH4, NaBH4, LiBH4, BH3,
H2/Raney Ni, and Li/NH3, have been known to be useful for the reductive
ring-opening of epoxides to alcohols.[2] Furthermore various metal halides,
such as SmI2, InCl3, InBr3, CeCl3, MgBr2, and SmCl3, were used in
the regio- and stereoselective ring-opening reaction of epoxides.[2,3]
Received in Japan February 13, 2005
Address correspondence to Shinsei Sayama, Department of Chemistry, Fukushima
Medical University, Hikariga-oka, Fukushima 960-1295, Japan. E-mail: ssayama@
fmu.ac.jp
2115

2116
S. Sayama
Selective azidolysis and conversion into haloalcohols of epoxides both were
accomplished in the presence of quaternary ammonium halides Bu4NX
(X ¼ F, Cl, Br, I).[4]
On the other hand, combinations of complex metal hydrides (LiAlH4,
NaBH4) and antimony halides (SbCl3, SbBr3) were reported to be more
effective for the conjugate reduction of 2-butene-1,4-diones and the
reductive debromination of aromatic a-bromo ketones in comparison with
those of complex metal hydrides and other metal halides (AlCl3, CuCl2,
FeCl3) in previous papers.[5] Antimony halides are more effective for
organic synthesis and are easier to handle than other metal halides, such as
AlCl3 and TiCl4. Moreover, the epoxidation of 2-butene-1,4-diones was
also reported in a previous paper to be in the presence of a catalytic amount
of BuN4I.[6] Therefore, there has been much interest in the effect of the use
of antimony(III) halide in the presence of quaternary ammonium halides for
the reductive ring-opening reaction of 2,3-epoxy-1,4-butanediones.[7] In this
article, we report the results of our studies concerning the ring-opening
reaction of various epoxides with SbCl3-Bu4NX (X ¼ Cl, Br, I).
The ring-opening reaction of cis-1,4-diphenyl-2,3-epoxy-1,4-butanedione
(1), chosen as a representative 2,3-epoxy-1,4-butanedione for this study, with
SbCl3-Bu4NI in various stoichiometric ratios was carried out in the presence
.
of Na2S2O3 5H2O. The results are summarized in Table 1. Epoxybutanedione
1 was mostly recovered unchanged at the molar ratio of 1, Bu4NI,
.
Na2S2O3 5H2O, and SbCl3 (1 : 1 : 1.8 : 0.2, run 1). A mixture of hydroxydike-
tone 2 and hydroxyenedione 3 was obtained even in the presence of 2.0 molar
equivalents of Bu4NI over 1 (run 2). Because the yields of hydroxydiketones 2
and 3 were not satisfactory in the presence of a catalytic amount of SbCl3, the
reaction of epoxydiketone 1 was carried out with 1.0–2.0 molar equivalents of
SbCl3 over 1. At less than 2.0 molar equivalents of SbCl3 and Bu4NI over 1,
hydroxydiketone 2 was not obtained in high yields (runs 3–5). At the 2.0
molar equivalents of SbCl3 and Bu4NI over 1, epoxydiketone 1 was
converted to hydroxydiketone 2 in good yield (run 6), whereas at less than
equimolar of Bu4NI over SbCl3, hydroxydiketone 2 was not afforded in good
yields (runs 7 and 8). Therefore, the reaction of epoxydiketone 1 with 3.0
molar equivalents of SbCl3 and Bu4NI over 1 was expected to give hydroxy-
diketone 2 in satisfactory yield. At 3.0 molar equivalents of SbCl3 and Bu4NI
over 1, hydroxydiketone 2 was obtained in the expected 90% yield (run 9).
Furthermore, the yield of 2 was also satisfactory at excess molar equivalents
of Bu4NI over SbCl3 (run 10). Subsequent experiments were carried out to
.
clarify the effect of SbCl3, Bu4NI, and Na2S2O3 5H2O. Epoxydiketone 1
was recovered unchanged only with 4.0 molar equivalents of SbCl3 over 1
.
in the presence of Na2S2O3 5H2O (run 11). Epoxydiketone 1 was also
recovered unchanged only with 4.0 molar equivalents of Bu4NI over 1 in
.
.
the presence of Na2S2O3 5H2O (run 12). In the absence of Na2S2O3 5H2O,
the yield of 2 with SbCl3 and Bu4NI was not fully satisfactory, accompanied
by cis-enedione 5 (2 : 43%, 5 : 49%). The reaction of epoxydiketone 1 even

Reductive Ring-Opening of Epoxides
2117
Table 1. Reductive ring-opening reaction of cis-1,4-diphenyl-2,3-epoxy-1,4-butane-
dione 1 with SbCl3-Bu4NI in THF at 0–238Ca
Molar ratio/1
Yield (%)b
Run
SbCl3
Bu4NI
2
3
4
5
1
1
2
0.2
0.2
1.0
1.5
1.5
2.0
3.0
3.0
3.0
3.0
4.0
—
1.0
2.0
2.0
0.5
1.0
2.0
1.0
2.0
3.0
4.0
—
8
8
—
—
2
—
—
8
83
—
33
18
22
—
45
7
28
46
52
59
83
37
63
90
90
—
—
54
—
3
3
4
5
3
5
5
10
3
—
—
—
4
6
12
6
7
2
8
7
5
9
—
—
—
—
3
3
—
—
99
98
10
11
12
—
—
—
—
—
—
4.0
a1: 0.4 mmol; THF: 15 mL; in the presence of Na2S2O3 5H2O (0.72 mmol); time:
.
65 h.
bIsolated products were purified by column chromatography on silica gel. Yields
1
were also determined by H NMR analysis of crude products.
.
with SbBr3-Bu4NI instead of SbCl3-Bu4NI in the absence of Na2S2O3 5H2O
did not afford hydroxydiketone 2 for 65 h at room temperature (recovered 1 :
60%, 5 : 30%). Hydroxydiketone 2 was predominantly obtained in the
reductive ring opening of epoxydiketone 1 with SbCl3-Bu4NI in the
.
presence of Na2S2O3 5H2O for 19 h at room temperature, but with a less sat-
isfactory yield of 2 (64%) along with recovered 1 (31%). Accordingly, the
optimum conditions for the reductive ring-opening of 2,3-epoxy-1,4-butane-
dione are as follows. The combination of SbCl3 and Bu4NI was found to be
essential for reductive ring-opening of 2,3-epoxy-1,4-butanedione in the
[7]
presence of Na2S2O3 5H2O. It needs about three molar equivalents of
.
SbCl3 and Bu4NI over 2,3-epoxy-1,4-butanedione to give hydroxy-1,4-buta-
nedione in high yield. Prolonged reaction time of more than 48–60 h is
needed to obtain 2 in nearly quantitative yield at room temperature.

2118
S. Sayama
To clarify the effect of the combination of SbCl3 and Bu4NI in the
.
presence of Na2S2O3 5H2O for the reductive ring opening of 1 to 2, the
reaction of epoxydiketone 1 was carried out with other metal halides and
iodo compounds. Epoxydiketone 1 was recovered unchanged in greater than
over 50% yields with other metal halides (AlCl3, CuCl2, FeCl3)-Bu4NI in
.
the presence of Na2S2O3 5H2O. Moreover, hydroxydiketone 2 was not
afforded in good yields with the combination of SbCl3 and I2 or KI instead
of Bu4NI. Thus, the combination of SbCl3 and Bu4NI was found to be more
effective for the reductive ring-opening reaction of epoxydiketone 1 to hydro-
xydiketone 2 than those of other metal halides—Bu4NI or SbCl3—other iodo
reagents.
The reductive ring-opening reaction of various aromatic and aliphatic 2,3-
epoxy-1,4-diones was carried out to elucidate the application of the com-
bination SbCl3 and Bu4NI system. The results are shown in Table 2. The
reaction of trans-1,4-diphenyl-2,3-epoxy-1,4-butanedione (6) and ethyl
3-benzoyl-2,3-epoxypropionate (7) also took place to give the corresponding
2-hydroxy-1,4-diones (2, 8) in good yields under the same reaction conditions
(runs 1 and 2). trans-2,3-Epoxy-1-phenyl-1,4-pentanedione (9) was similarly
converted to a mixture of 3-hydroxy- and 2-hydroxy-1-phenyl-1,4-pentane-
diones (10, 11, run 3). trans-3,4-Epoxy-2,5-decanedione (12) was also
converted to a 1 : 1 mixture of 3-hydroxy- and 4-hydroxy-2,5-decanediones
(13, 14) in good yields (run 4). Thus, the combination of SbCl3 and Bu4NI
was ascertained to be useful for the reductive ring opening of 2,3-epoxy-
1,4-diones to hydroxy-1,4-diones.
To examine the limitations and chemoselectivity for the reductive ring
opening of epoxides with the combination of SbCl3 and quaternary
ammonium halides (Bu4NX: X ¼ I, Br, Cl) system, the reaction of various
epoxides was carried out under the same reaction conditions. The results are
shown in Table 3. At first, the reaction of epoxydiketone 6 was carried out
with SbCl3-Bu4NX (X ¼ Br, Cl). Epoxydiketone
6 was recovered
unchanged, respectively. Bu4NI also turned out to be the most useful for
reductive ring opening of 6 in quaternary ammonium halides Bu4NX (X ¼ I,
Br, Cl, runs 1 and 2). On the other hand, unexpectedly, carvone oxide (15)
was converted to the respective haloalcohols 16–18 with SbCl3-Bu4NX
(X ¼ I, Br, Cl, runs 3–5). These results suggested that the reductive ring-
opening reaction did not occur in terminal epoxides such as carvone oxide
even with SbCl3-Bu4NI. To show the transformation of terminal epoxides to
haloalcohols with this method, the reaction of 10, 11-epoxy-1-undecanol
(19) was examined under the same reaction conditions. Terminal epoxide 19
was converted to the corresponding haloalcohols 20–22 as expected (runs
6–8). Consequently, the SbCl3-Bu4NX (X ¼ I, Br, Cl) systems were found
to be useful and regioselective methods for converting terminal epoxides
into respective haloalcohols. The reaction of aliphatic cyclic epoxides (23,
25) was also carried out to examine the limitations and chemoselectivity of
this system. a-Ionone oxide 23 was not converted to iodoalcohol 24 in high

Reductive Ring-Opening of Epoxides
2119
Table 2. Reductive ring-opening reaction of trans-2,3-epoxy-1,4-butanedione with
SbCl3-Bu4NI in THF at 0–238Ca
Substrates
R1 R2
Ph Ph
Products
Run
(S)
R1
Ph
R2
(a)
Yield/%b
1
2
3
6
7
9
Ph
2
8
90
96
55
27
41
39
Ph
Ph
OEt
Me
Ph
Ph
OEt
Me
10
11ꢀ
13
14ꢀ
Me
C5H12
Me
Ph
Me
4
C5H12
Me
12
C5H12
aS: 0.4 mmol; molar ratio: 1 : 3 : 3 (S/SbCl3/Bu4NI); THF: 15 mL; in the presence of
.
Na2S2O3 5H2O (0.72 mmol); time: 65 h.
bIsolated products were purified by column chromatography on silica gel. Yields
1
were also determined by H NMR analysis of crude products.
ꢀ2-Hydroxy-1-phenyl-1,4-pentanedione (11): Rf ¼ 0.41 (CH3CO2Et/CHCl3, 1 : 3).
IR (neat, cm21) 3420, 1717, 1686, 1599, 1580, 1450, 1404, 1361, 1261, 1216, 1181,
1100, 1038, 1004, 988, 936, 758. 1H NMR (CDCl3) d 2.25 (3H, s), 2.76 (1H, dd,
J ¼ 17.5, 7.4 Hz), 2.88 (1H, dd, J ¼ 17.5, 3.5 Hz), 5.45 (1H, dd, J ¼ 7.4, 3.5 Hz),
7.45–7.64 (3H, m), 7.91–7.97 (2H, m). 13C NMR (CDCl3) d 30.99, 48.12, 69.99,
128.69, 128.87, 133.35, 133.94, 200.35, 205.80.
4-Hydroxy-2,5-decanedione (14): Rf ¼ 0.48 (CH3CO2Et/CHCl3, 1 : 3). IR (neat,
cm21) 3414, 2960, 2934, 2874, 1717, 1460, 1406, 1365, 1247, 1172, 1112, 1073,
1
1038, 959. H NMR (CDCl3) d 0.88 (3H, t, J ¼ 7.2 Hz), 2.22 (3H, s), 2.85 (1H, dd,
J ¼ 13.5, 5.9 Hz), 2.95 (1H, dd, J ¼ 13.5, 4.1 Hz), 4.35 (1H, dd, J ¼ 5.9, 4.1 Hz).
yield (run 9), whereas the reaction of isophorone oxide 25 with SbCl3-Bu4NI
took place to give isophorone 26 unexpectedly (run 10). These results suffi-
ciently accounted for the regioselective ring opening of terminal epoxides to
haloalcohols with SbCl3-Bu4NX (X ¼ I, Br, Cl).
In conclusion, the SbCl3-Bu4NI system in the presence of
.
Na2S2O3 5H2O provided an alternative procedure for reductive ring
opening of 2,3-epoxy-1,4-butanediones to hydroxy-1,4-butanediones chemo-
selectively. The SbCl3-Bu4NX (X ¼ I, Br, Cl) systems were also useful and
[regioselective for the ring opening of terminal epoxides to the respective
haloalcohols under the same reaction conditions].

2120
S. Sayama
Table 3. Ring-opening reaction of epoxides with SbCl3-Bu4NX in THF at 0–238Ca
Run
1
Substrates
(S)
Bu4NXb
B
Products
Yields/%c
6/85
6
Recovered
2
3
6
15
C
A
Recovered
6/88
16/66
4
5
15
15
B
C
17/78
18/90
6
7
19
19
A
B
20/65
21/82
8
9
19
23
C
A
22/84
24ꢀ/40d
10
25
A
26/77e
aS: 0.4 mmol; molar ratio: 1 : 3 : 3 (S/SbCl3/Bu4NX); THF: 15 mL; in the presence
.
of Na2S2O3 5H2O (0.72 mmol); time: 65 h.
bA ¼ Bu4NI, B ¼ Bu4NBr, C ¼ Bu4NCl.
cIsolated products were purified by column chromatography on silica gel. Yields
1
were also determined by H NMR analysis of crude products.
dRecovered 23: 39%.
eRecovered 25: 20%.
ꢀIodoalcohol (24): Rf ¼ 0.33 (CHCl3/EtOAc, 5 : 1). IR (neat, cm21) 3474, 2950,
2334, 1659, 1458, 1365, 1309, 1265, 1220, 1176, 1106, 1058, 990, 938, 853. 1H
NMR (CDCl3) d 0.89 (3H, s), 1.07 (3H, s), 1.38 (3H, s), 2.29 (3H, s), 1.41–1.43
(1H, m), 1.75–1.90 (2H, m), 2.24–2.38 (1H, m), 2.40 (1H, d, J ¼ 10.5 Hz), 4.43
(1H, t, J ¼ 2.0 Hz), 6.12 (1H, d, J ¼ 16.0), 6.94 (1H, dd, J ¼ 16.0, 10.5 Hz). 13C
NMR (CDCl3) d 23.14, 27.15, 28.77, 32.11, 33.64, 34.35, 36.94, 44.27, 52.95,
73.40, 134.75, 145.96, 198.36.

Reductive Ring-Opening of Epoxides
EXPERIMENTAL
2121
IR spectra were recorded on a Perkin Elmer Spectrum One FT-IR spectropho-
1
tometer. H and 13C NMR spectra were recorded on a JEOL JNM-EX270
spectrometer, and the chemical shifts are given relative to the internal
SiMe4 standard. MS spectra were run on a Bruker Daltonics–APEX III and
a JEOL-HX110.
General Procedure for the Synthesis of 2,3-Epoxy-1,4-butanedione[6]
To a solution of 2-butene-1,4-dione (1 mmol) and Bu4NI (0.1 mmol) in THF
(10 mL) at 08C was added dropwise 30% aq. H2O2 (5–10 mmol) dissolved
in THF (3 mL). After stirring for 20–36 h at 0–238C, the reaction mixture
was poured into 0.5 M of aq. KI. The resulting mixture was treated with
0.5 M of aq. Na2S2O3 and extracted with ethyl acetate. The organic layer
was washed with 0.5 M of aq. Na2S2O3 and successively saturated aq. NaCl
and dried by MgSO4. After removal of solvent in vacuo, the residue was
purified by recrystallization or column chromatography on silica gel
(Wakogel C-200) with CCl4 and CHCl3 (1 : 1, v/v). Epoxydiketones were
obtained in 56–91% yields.
Typical Procedure for the Ring Opening of Epoxide
To a solution of SbCl3 (273 mg, 1.2 mmol), Bu4NI (442 mg, 1.2 mmol) and
.
Na2S2O3 5H2O (178 mg, 0.72 mmol) in THF (12 mL) at 08C, 1,4-diphenyl-
2,3-epoxy-1,4-butanedione 1 (100 mg, 0.4 mmol) in THF (3 mL) was added.
The reaction mixture was treated with 1.0 M of aq. NaHCO3 after stirring
for 64 h at temperatures between 08C and rt and extracted with ethyl
acetate. The organic layer was washed with 0.5 M of aq. Na2S2O3 and succes-
sively saturated aq. NaCl and dried over MgSO4. After removal of the solvent
in vacuo, the residue was purified by column chromatography on silica gel
(Wakogel C-200) with CCl4 and CHCl3 (1 : 1, v/v). Hydroxydiketone 2
(91 mg, 0.36 mmol) was obtained in 90% yield.
2-Hydroxy-1,4-diphenyl-1,4-butanedione (2). Mp 92–938C. Rf ¼ 0.25
(CHCl3). IR (KBr, cm21) 3406, 1682, 1599, 1448, 1325, 1305, 1203, 1108,
1
1048, 1009, 754. H NMR (CDCl3) d 3.36 (1H, dd, J ¼ 16.2, 5.4 Hz), 3.44
(1H, dd, J ¼ 16.2, 6.0 Hz), 5.67 (1H, dd, J ¼ 6.0, 5.4 Hz), 7.26–7.63 (6H,
m), 7.91–8.01 (4H, m). 13C NMR (CDCl3) d 43.50, 70.06, 128.26, 128.62,
128.67, 128.87, 133.51, 133.60, 133.87, 136.62, 197.14, 200.68. Anal.
calcd. for C16H14O3 C, 75.57; H, 5.55. Found: C, 75.48; H, 5.60.
Ethyl 2-hydoxy-4-oxo-4-phenylbutanoate (8). Rf ¼ 0.17 (CHCl3). IR
(neat, cm21) 3446, 3066, 2984, 2914, 1742, 1686, 1599, 1580, 1450, 1369,
1
1274, 1214, 1102, 1042, 1002, 936, 864, 758. H NMR (CDCl3) d 1.29
(3H, t, J ¼ 7.2 Hz), 3.45 (1H, dd, J ¼ 17.0, 5.9 Hz), 3.54 (1H, dd, J ¼ 17.0,

2122
S. Sayama
4.0 Hz), 4.26 (2H, q, J ¼ 7.2 Hz), 4.66 (1H, dd, J ¼ 5.9, 4.0 Hz), 7.43–7.62
(3H, m), 7.93–7.97 (2H, m). 13C NMR (CDCl3) d 14.03, 42.12, 61.76,
67.15, 128.10, 128.62, 133.51, 136.38, 173.71, 197.44. HR-ESI-MS
[M þ Na]þ m/z 245.0789 (calcd. for C12H14O4Na: 245.0784).
3-Hydroxy-1-phenyl-1,4-pentanedione (10). Rf ¼ 0.41 (CH3CO2Et/
CHCl3, 1 : 3). IR (neat, cm21) 3420, 1717, 1686, 1599, 1580, 1450, 1404,
1361, 1261, 1216, 1181, 1100, 1038, 1004, 988, 936, 758. 1H NMR
(CDCl3) d 2.33 (3H, s), 3.39 (1H, dd, J ¼ 17.5, 5.9 Hz), 3.56 (1H, dd,
J ¼ 17.5, 3.5 Hz), 4.52 (1H, dd, J ¼ 5.9, 3.5 Hz), 7.45–7.64 (3H, m), 7.91–
7.97 (2H, m). 13C NMR (CDCl3) d 25.55, 41.58, 73.85, 128.23, 128.60,
133.74, 136.28, 198.29, 209.57. Anal. calcd. for C11H12O3; C, 68.73; H,
6.29. Found: C, 68.65; H, 6.40.
3-Hydroxy-2,5-decanedione (13). Rf ¼ 0.48 (CH3CO2Et/CHCl3, 1 : 3).
IR (neat, cm21) 3414, 2960, 2934, 2874, 1717, 1460, 1406, 1365, 1247,
1
1172, 1112, 1073, 1038, 959. H NMR (CDCl3) d 0.88 (3H, t, J ¼ 7.2 Hz),
2.26 (3H,s), 2.45 (1H, dd, J ¼ 13.5, 5.9 Hz), 2.55 (1H, dd, J ¼ 13.5,
4.1 Hz), 4.00 (1H, dd, J ¼ 5.9, 4.1 Hz). Anal. calcd. for C10H18O3: 64.49;
H, 9.74. Found: C, 64.33; H, 9.95.
Iodoalcohol (16). Rf ¼ 0.11 (CHCl3). IR (neat, cm21) 3438, 2976, 2924,
2898, 1663, 1452, 1435, 1417, 1373, 1305, 1259, 1189, 1104, 1058, 1009,
1
957, 907, 845, 803, 754, 714. H NMR (CDCl3) d 1.34 (3H, s), 1.78 (3H,
s), 2.24–2.75 (5H, m), 3.36 (1H, dd, J ¼ 10.8, 2.7 Hz), 3.42 (1H, dd,
J ¼ 10.8, 3.5 Hz), 6.80 (1H, m). 13C NMR (CDCl3) d 15.52, 20.52, 23.70,
26.50, 39.57, 42.91, 71.21, 135.41, 144.07, 199.15. HR-ESI-MS m/z
317.0012 [M þ Na]þ (calcd. for C10H15O2I Na: 317.0009).
Bromoalcohol (17). Rf ¼ 0.50 (CH3CO2Et/CHCl3, 1 : 2). IR (neat, cm21
1
1056, 1013, 961, 926, 907, 824, 801, 754. H NMR (CDCl3) d 1.31 (3H, s),
)
3422, 2978, 2926, 1663, 1452, 1435, 1373, 1305, 1259, 1183, 1108, 1079,
1.78 (3H, s), 2.21–2.70 (5H, m), 3.45–3.57 (2H, m), 6.77 (1H, m).
13C NMR (CDCl3) d 15.51, 21.37, 27.24, 38.43, 41.99, 43.02, 71.96,
135.36, 145.03, 199.24. HR-ESI-MS m/z 269.0148 [M þ Na]þ, 271.0129
[(M þ 2) þ Na]þ (calcd. for C10H15O2Br Na: 269.0148).
Chloroalcohol (18). Rf ¼ 0.50 (CH3CO2Et/CHCl3, 1 : 2). IR (neat, cm21
)
3442, 2978, 2928, 1663, 1452, 1435, 1373, 1307, 1259, 1183, 1154, 1108,
1
1058, 1013, 961, 930, 907, 828, 748, 714. H NMR (CDCl3) d 1.27 (3H, s),
1.77 (3H,s), 2.18–2.67 (5H, m), 3.52–3.67 (2H, m), 6.77 (1H, m). 13C
NMR (CDCl3) d 15.47, 21.87, 27.11, 39.19, 41.51, 52.29, 72.66, 135.14,
145.04, 199.63. HR-ESI-MS m/z 225.0654 [M þ Na]þ, 227.0626
[(M þ 2) þ Na]þ (calcd. for C10H15O2Cl Na: 225.0653).
Iodoalcohol (20). Rf ¼ 0.33 (CH3CO2Et/CHCl3, 1 : 3). IR (neat, cm21
)
3332, 2928, 2858, 1460, 1417, 1185, 1056, 721.1H NMR (CDCl3) d 1.13–
1.55 (16H, m), 3.22 (1H, dd, J ¼ 10.8, 6.4 Hz), 3.38 (1H, dd, J ¼ 10.8,
5.4 Hz), 3.51 (1H, m), 3.62 (2H, t, J ¼ 6.7 Hz). 13C NMR (CDCl3) d 16.49,
25.55, 25.62, 29.20, 29.27, 29.32, 32.65, 36.49, 62.89, 70.87. HR-ESI-MS
m/z 337.0638 [M þ Na]þ (calcd. for C11H23O2I Na: 337.0636).

Reductive Ring-Opening of Epoxides
2123
Bromoalcohol (21). Rf ¼ 0.32 (CH3CO2Et/CHCl3, 1 : 3). IR (neat, cm21
)
3256, 2926, 2858, 1460, 1425, 1375, 1340, 1224, 1054, 721. 1H NMR (CDCl3)
d 1.30–1.57 (16H, m), 3.34–3.77 (5H, m). 13C NMR (CDCl3) d 25.53,
25.68, 29.32, 29.40, 32.74, 35.07, 40.54, 62.98, 71.03. HR-ESI-MS m/z
289.0776 [M þ Na]þ, 291.0756 [(M þ 2) þ Na]þ (calcd. for C11H23O2Br Na:
289.0774).
Chloroalcohol (22). Rf ¼ 0.25 (CH3CO2Et/CHCl3, 1 : 3). IR (neat, cm21
)
3302, 2930, 2858, 1464, 1056, 721. 1H NMR (CDCl3) d 1.25–1.56 (16H, m),
3.44–3.79 (5H, m). 13C NMR (CDCl3) d 25.46, 25.68, 29.27, 29.34,
29.38, 29.43, 32.74, 34.19, 50.53, 63.02, 71.43. HR-ESI-MS m/z
245.1281 [M þ Na]þ, 247.1251 [(M þ 2) þ Na]þ (calcd. for C11H23O2Cl
Na 245.1279).
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