Pyridine and triphenylphosphine oxide activation of sulfonyl chlorides in the syntheses of (E) alk-1-enyl sulfones

Article abstract of DOI:10.1016/j.tet.2008.09.056

This paper describes efficient and new approaches to (E) alk-1-enyl sulfones, starting from sulfonyl chloride/pyridine or sulfonyl chloride/triphenylphosphine complexes in the presence of (E) di-iso-butyl alk-1-enyl alanes. The use of CuCl in the presence of sulfonyl chloride/pyridine complexes or pyridine in the presence of sulfonyl chloride/triphenylphosphine complexes, respectively, results in a remarkable increase in the yields and conversions.

Full text of DOI:10.1016/j.tet.2008.09.056

Tetrahedron 64 (2008) 11218–11223
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Pyridine and triphenylphosphine oxide activation of sulfonyl chlorides in the
syntheses of (E) alk-1-enyl sulfones
*
G. Signore, C. Malanga, R. Menicagli
Dipartimento di Chimica e Chimica Industriale, via Risorgimento 35, 56126 Pisa, Italy
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 6 June 2008
Received in revised form 4 September 2008
Accepted 18 September 2008
Available online 26 September 2008
This paper describes efficient and new approaches to (E) alk-1-enyl sulfones, starting from sulfonyl
chloride/pyridine or sulfonyl chloride/triphenylphosphine complexes in the presence of (E) di-iso-butyl
alk-1-enyl alanes.
The use of CuCl in the presence of sulfonyl chloride/pyridine complexes or pyridine in the presence of
sulfonyl chloride/triphenylphosphine complexes, respectively, results in a remarkable increase in the
yields and conversions.
Ó 2008 Elsevier Ltd. All rights reserved.
1. Introduction
2. Results and discussion
Alk-1-enyl sulfones are useful intermediates in organic syn-
thesis, but usually do not represent final target molecules.1–10
Oxidation of sulfides,11–14 metathesis,15 addition of C-nucleo-
philes on acetylenic sulfones,16–18 radical addition of sulfonyl ha-
lides on alkynes,19,20 reaction of sulfonyl derivatives with vinyl
organometallic reagents (Sn,21 Zr,22 Hg23), addition/elimination
reactions24,25 and Knoevenagel condensation26–28 represent valu-
able synthetic approaches to these targets.
In the organometallic chemistry field, our main area of interest,
it should be noted that the reactions of alk-1-enyl derivatives of Sn
need the employment of transition metal catalysts.21 On the other
hand the reactions involving alk-1-enyl mercurials require unusual
reaction conditions incompatible with various functional groups.23
The alkenylzirconocenes are not commonly available.22
In a preliminary experience, a CH2Cl2 solution of (E) di-iso-butyl
hex-1-enyl alane was slowly (30 min) added to the preformed tosyl
chloride/pyridine complex, in the same solvent to give, after hy-
drolysis, the desired sulfone in 47% yield along with the starting
sulfonyl chloride (50%) (Scheme 1).
An almost quantitative conversion (96%) and yield (90%) could
be obtained by performing a faster addition (10–20 s) of the orga-
noalane to the sulfonyl chloride/pyridine complex. The results
obtained by using different dialkyl alk-1-enyl alanes are shown in
Table 1. The sulfone was the only product obtained, as confirmed by
the amount of sulfonyl chloride recovered after hydrolysis.
The fluctuations in the reaction yields and conversions in
alkenyl sulfones could be caused by some side reactions deacti-
vating one or both the reagents.
Recently alkenyl sulfoxides were easily synthesised, starting
from sulfonyl chlorides and dialkyl alkenyl alanes.29,30 It was in-
teresting to verify if this reactivity could be exploited to the syn-
thesis of alkenyl sulfones too.
The slow addition of organometallic species to the sulfonyl
chloride/pyridine complex (cf. entry 1, Table 2) may release pyridine
that could complex the alkyl alkenyl alane, lowering its reactivity
and inhibiting the reaction. Further evidence of the inhibiting effect
of pyridine was obtained by NMR analyses of the reaction mixture in
which the presence of pyridine/alkenyl alane complex was detected.
This hypothesis was verified performing the reaction employing
pyridinated di-iso-butyl hex-1-enyl alane; in this case no traces of
sulfone were recovered.
The addition of a pyridine complexing agent stronger than the
organoalane would increase the yields. In a further experience di-
iso-butyl 3,3-dimethylbut-1-enyl alane was reacted with tosyl
chloride/pyridine complex; when a stationary conversion (z50%)
was achieved, CuCl (0.5 mol) was added.
This idea was suggested by the formation of appreciable amount
of sulfones as byproducts in the synthesis of sulfoxides and by
preliminary observations on the reactivity of alkenyl alanes with
sulfonyl pyridinates, recently reported.30,31
On the basis of this data,30,31 it was reasonable to suppose that
a sulfonyl chloride/pyridine complex could represent the key in-
termediate in the preparation of an alkenyl sulfone.
In these reaction conditions, a remarkable increase in conver-
sion occurred, and the sulfone was recovered in satisfactory yield
(70%) (Scheme 2).
* Corresponding author. Tel.: þ39 050 2219281; fax: þ39 050 2219260.
E-mail address: rime@dcci.unipi.it (R. Menicagli).
0040-4020/$ – see front matter Ó 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2008.09.056

G. Signore et al. / Tetrahedron 64 (2008) 11218–11223
11219
O O
S
Bu-n
O O
S
O O
S
Cl
(i.Bu)2Al
(Slow add.)
CH2Cl2, r.t.
N
Cl
Bu-n
+
Me
Me
Me
50%
47% (1)
Scheme 1. Reaction of di-iso-butyl hex-1-enyl alane with tosyl chloride/pyridine complex.
The reaction was performed on different substrates, and the
results obtained are shown in Table 2.
Table 1
Reaction of dialkyl alkenyl alanes with sulfonyl chloride/pyridine complexes
Increase in conversion and yield depends on the amount of
copper chloride and the nature of the alkenyl chain transferred.
No traces of sulfone were obtained when the addition of CuCl
was performed immediately before or after the organo alanes.
Products arising form the S–S coupling of the sulfonyl functional
groups were isolated.32,33 In these reaction conditions, the forma-
tion of R3Al/CuCl complex promotes undesired side reactions. In
our opinion the role of CuCl appears to be connected to a free
pyridine-scavenging activity: during the course of the reaction, free
pyridine is obtained. In order to avoid the formation of the
unreactive alane/pyridinate complex, CuCl is added to subtract the
pyridine and regenerate the free alane.
This behaviour seems to be confirmed by the dark blue colour
solution attributable to the formation of a Cu/Py complex.
The use of a different sulfonated intermediate, such as the TsCl/
(Ph)3PO complex, scarcely investigated,34 was expected to be more
effective towards organo alanes than the previously examined TsCl/
Py system.
Entrya
(i-Bu)2AlR
Product
Conversionb % Yieldc
%
O
O
S
1
Bu-n
1 96
2 72
3 57
4 45
90
68
54
40
Bu-n
Me
Me
O
O
O
S
2
3
4
Hex-c
Bu-t
Hex-c
Bu-t
O
S
Me
O
O
S
Ph
Ph
Me
On this basis, the possibility to employ catalytic amounts of
(Ph)3PO in the presence of TsCl to obtain in situ TsCl/(Ph)3PO was
very intriguing.
In a first attempt (Scheme 3), TsCl was reacted with pyridinated
di-iso-butyl hex-1-enyl alane in the presence of a catalytic amount
(15%) of (Ph)3PO.
O O
S
5d
Bu-n
5 n.d.e
75
Me
Bu-n
a
All reactions were performed by rapid addition of the alane to a CH2Cl2 solution
of sulfonyl chloride/pyridine complex at rt.
b
Based on the recovered sulfonyl chloride.
Calculated on the isolated, chemically pure product.
Methanesulfonyl chloride was used.
Work-up procedure did not allow for the recovery of the starting material.
Sulfone (1) was recovered with a partial conversion (50%) and
yield (48%).
c
d
Better results were obtained when a large excess of pyridine was
employed; in this case (Scheme 4) quantitative conversion of the
starting TsCl and 75% yield in the desired sulfone (1) were obtained.
A minor amount (2 or 3 equiv) of pyridine caused a reduction in
the yields (10–20%). A rationale of the mechanism is shown in the
Scheme 5.
e
Table 2
Effect of copper chloride on the reaction yield
Entrya
(i-Bu)2AlR
Product
Yieldb (%) Yieldb,c (%)
Starting from the point of view that (B) (Scheme 5) is unreac-
tive30 and (A) shows a different reactivity29 towards alanes, it is
possible to suppose that (C) represents the effective intermediate.
Since the dialkyl alane chloride formed can inhibit the reaction,
interacting with the Ph3PO, the presence of pyridine in excess
(15 equiv) is necessary for the formation of (F) restoring the free
Ph3PO.
The data obtained in the described experimental conditions, by
using different substrates, are collected in Table 3.
No remarkable influence of transferred chains, reaction times
and yields has been observed.
O
O
S
1d
Bu-n
1
2
3
49
72
54
75
80
69
Bu-n
Hex-c
Bu-t
Me
Me
Me
O
O
S
2
3
Hex-c
Bu-t
O
O
S
The sole limitation of this procedure, compared with the pre-
vious one, is represented by the poor yield obtained when meth-
anesulfonyl chloride is used (Table 3, entry 6).
O
O
S
3. Conclusions
4
Ph
4
40
62
Ph
Me
Two new methodologies for the synthesis of alkenyl sulfones are
here reported; the use of sulfonyl chloride/pyridine complexes
gives access to many structurally different aryl- and alkenyl
sulfones.
The addition of opportune amounts of CuCl to the reaction
mixture improves the yields.
a
All reactions were performed by rapid addition of the organoalane to the pre-
formed TsCl/pyridine complex; the reaction was allowed to reach a stationary
conversion and 0.5 equiv of copper chloride was added.
b
GC with internal standard: n-nonadecane.
GC after addition of CuCl.
A slow addition of the organoalane was performed (cf. entry 1, Table 1).
c
d

11220
G. Signore et al. / Tetrahedron 64 (2008) 11218–11223
O O
S
O O
S
Bu-t
O O
S
Cl
(i-Bu)2Al
(Fast add.)
CH2Cl2, r.t.
Bu-t
Bu-t
N
CuCl (0.5 equiv.)
r.t. 30 min
Reagents
+
Me
Me
Me
54% (3)
70% (3)
Scheme 2. Increase in conversion upon addition of copper chloride.
Bu-n
Ph3PO (15%) or
CuCl (0.50 mol)
O O
S
O O
S
(i-Bu)2Al
N
+
Bu-n
Cl
CH2Cl2, rfx.,
Me
Me
48% (1)
Scheme 3. Reaction between pyridinates di-iso-butyl hex-1-enyl aluminium and TsCl in the presence of Ph3PO.
Sulfonyl chloride/Ph3PO complexes, obtained in situ from sul-
fonyl chlorides and catalytic amounts of Ph3PO, are useful in-
termediates to obtain alkenyl sulfones in good yields (70–76%). The
appreciable results obtained in this procedure represent a new
synthetic approach to alkenyl sulfones and offer a new appeal to-
wards alane chemistry.
carrier gas. Thin layer chromatography (TLC) analyses were per-
formed on silica gel 60 plates (Fluka) and flash chromatography pu-
rifications were carried out on silica gel 60 (Fluka, 230–400 mesh)
usingtheelutingmixtures(v/v)reportedforeachcase. Meltingpoints
were determined using a Kofler hot stage apparatus and are not
corrected. 1H and 13C NMR (200 and 50 MHz, respectively) spectra
were recorded on a Varian Gemini 200 spectrometer; all NMR data
Further studies are in progress to clarify the mechanism of the
reaction.
were obtained using CDCl3 solutions. Chemical shifts (d, ppm) are
referredtotetramethylsilane(1HNMR)orCDCl3 (13CNMR)asinternal
standard. Mass spectra (m/z, I%) were taken on a 5980 Hewlett-
Packard GC instrument, equipped with an HP-5MS column
4. Experimental
(30 mꢀ0.25 mm, film 0.25
mm) interfaced with a Hewlett-Packard
4.1. General procedures and materials
5995A instrument, with He as carrier gas. Indicated yields are
reported on the isolated, chemically pure products. IR Spectra were
recorded on a Perkin Elmer FT-IR, 1760X spectrophotometer.
CH2Cl2 was refluxed on, and distilled from, P2O5. Di-iso-butyl al-
uminium hydride (DIBAL-H) was synthesised starting from Al(i-Bu)3.
Pyridine was purified by distillation and stored under an inert at-
mosphere until its use. Alkynes were distilled immediately before
use. GC analyses were performed on a Perkin–Elmer8500 instrument
4.2. Hydroalumination of alkynes
[ZB1capillarycolumn(15 mꢀ0.25 mm), film 0.25
m
m]equippedwith
In a typical run, a hexane solution of DIBAL-H (1.0 mL, 1 mmol)
was slowly added to a cooled (0 ꢁC) hexane solution (25 mL) of the
a flame ionisation detector and a split–splitless injector, with N2 as
O O
O O
Pyridine (15 eq)
S
S
Bu-n
Ph3PO (15%)
Cl
Bu-n
(i-Bu)2Al
+
N
CH2Cl2, rfx.,
30 min
Me
Me
75% (1)
Scheme 4. Reaction between pyridinates di-iso-butyl hex-1-enyl aluminium and TsCl in the presence of Ph3PO and an excess of pyridine.
O O
S
Cl
N
OPPh3
+
Cl
Py
(i-Bu)2Al
Me
(B)
(F)
+ Py - Py
+ Py - Py
O O
S
O O
S
R
OPPh3
Cl
R
(i-Bu)2Al
OPPh3
+
Cl
+
(i-Bu)2Al
Me
Me
(D)
(C)
O O
S
(i-Bu)2Al
O
PPh3 Cl
Cl
+ OPPh3
(E)
Me
(A)
Scheme 5. Proposed mechanism for the formation of (D).

G. Signore et al. / Tetrahedron 64 (2008) 11218–11223
11221
Table 3
Reaction of pyridinated dialkyl alkenyl alanes with sulfonyl chloride
Entrya
(i-Bu)2AlR
R0SO2Cl
Product
Yieldb (%)
75
O
O
O
O
S
S
1
6
2
Hex-n
Hex-n
Cl
O
O
O
O
S
S
S
2
3
4
Hex-c
Bu-t
70
76
71
Cl
Hex-c
Me
Me
Me
O
O
O
O
S
3
7
Cl
Bu-t
Me
O
O
O
O
S
S
Bu-n
Cl
Bu-n
O
O
O
O
S
S
5
6
Ph
4
5
70
20
Cl
Ph
Me
Me
O O
S
O O
S
Bu-n
Me
Me
Cl
Bu-n
O
O
Me
O
S
O
S
Me
7c
8
63d
Me
Cl
Me
Me
Me
a
All reactions were performed in CH2Cl2 at the reflux of the solvent, using a 20:1:0.15 pyridine/organoalane/Ph3PO ratio.
Calculated on the isolated chemically pure product.
The organometallic reagent was prepared in situ starting from AlCl3 and (R,S)-2-methylbutyl magnesium chloride.
Maximum yield was obtained after 92 h.
b
c
d
suitable alkyne (1.1 mmol). The mixture was refluxed for 5 h, then
three-necked flask, equipped with reflux condenser, dropping
funnel and magnetic stirrer. Pyridine (0.16 mL, 2 mmol) was added
to the reaction mixture and the solution stirred for 30 min. The
appropriate dialkyl alk-1-enyl alane (2 mmol), dissolved in CH2Cl2,
was quickly added to the reaction mixture. The solution was stirred
at room temperature until the conversion was stationary (usually
overnight), and variable amounts (1–2 mmol) of CuCl were added
to the reaction mixture. The blue solution was stirred at room
temperature until the maximum conversion was achieved, then
hydrolysed with an aqueous solution (1% v/v) of H2SO4. After ex-
traction with CH2Cl2 the organic layer was dried (Na2SO4). The
solvent was removed at reduced pressure (18 mmHg) and the crude
product purified by flash chromatography.
cooled to room temperature. The hexane was removed in vacuo
(18 mmHg), replaced with anhydrous CH2Cl2 (25 mL) and the so-
lution was used without further purification.
4.3. Synthesis of alk-1-enyl sulfones using sulfonyl chloride/
pyridine complexes and uncomplexed organo alanes
In a typical reaction, a three-necked flask equipped with reflux
condenser, dropping funnel and magnetic stirrer was thoroughly
dried and maintained under nitrogen atmosphere. The flask was
charged with TsCl (380 mg, 2 mmol), CH2Cl2 (20 mL) and pyridine
(0.16 mL, 2 mmol). The solution was stirred for 30 min and a CH2Cl2
solution (10 mL) of the appropriate dialkyl alk-1-enyl alane
(2 mmol) was rapidly added (10 s). After stirring (4 h), the reaction
mixture was hydrolysed with an aqueous solution of H2SO4 (1% v/
v), extracted with CH2Cl2 and dried on anhydrous Na2SO4. After
removal of the solvent at reduced pressure (18 mmHg), the product
was further purified by flash chromatography.
4.5. Synthesis of alk-1-enyl sulfones from sulfonyl chlorides
and pyridinated organo alanes in the presence of Ph3PO
In a typical reaction, a three-necked flask equipped with a reflux
condenser, a dropping funnel and a magnetic stirrer was dried and
charged with 2 mmol of the appropriate organoalane in CH2Cl2. The
solvent was removed at reduced pressure and CH2Cl2 (20 mL) and
pyridine (0.16 mL, 2 mmol) were added to the organometallic re-
agent. A catalytic amount (84 mg, 0.3 mmol) of PPh3O and TsCl
(342 mg, 1.8 mmol) was added to the resulting bright yellow so-
lution. The reaction mixture was refluxed for 1 h, cooled and
hydrolysed with the addition of an aqueous solution (1% v/v) of
4.4. Synthesis of alk-1-enyl sulfones using sulfonyl chloride/
pyridine complexes and uncomplexed organo alanes in the
presence of CuCl
In a typical experiment, TsCl (380 mg, 2 mmol) and CH2Cl2
(20 mL) were introduced under nitrogen atmosphere in a dry

11222
G. Signore et al. / Tetrahedron 64 (2008) 11218–11223
H2SO4. After extraction with CH2Cl2, the organic layer was dried
(Na2SO4) and then the solvent removed at reduced pressure
(18 mmHg). The product was further purified by flash
chromatography.
CH]CH–), 6.44 (dt, J¼14.8 Hz, J0¼1.5 Hz, 1H, SO2–CH]CH), 2.99 (s,
3H, CH3–SO2), 2.34 (dtd, J¼6.6 Hz, J0¼6.6 Hz, J00¼1.5 Hz, 2H, SO2–
CH]CH–CH2–), 1.60–130 (m, 4H, –CH2–CH2–CH3), 0.99 (t, J¼6.9,
3H, CH2–CH3); 13C NMR: 149.0, 129.6, 43.1, 31.3, 29.9, 22.4, 14.0; IR
(cmꢃ1): 2956, 2922, 2856, 2344, 1633, 1461, 1305, 1283, 1128, 967,
817. Anal. Calcd for C7H14O2S: C, 51.82; H, 8.70; O, 19.72; S, 19.76%.
Found: C, 51.79; H, 8.68; S, 19.80%.
4.6. Characterisation of the recovered sulfones
For each synthesised compound flash chromatography condi-
tion, physical state, mass spectroscopy data, 1H and 13C NMR data,
IR data and elemental analysis are reported.
4.6.6. 1-((E)-Oct-1-enylsulfonyl)benzene (6)
Hexane/ethyl acetate 80:20; yellowish oil; GC–MS (m/z, I%): 236
(Mꢂþ,10), 219 (28), 207 (17),188 (47),149 (17),126 (22),124 (53),117
(96),110 (50),104 (100), 91 (26), 78 (30), 69 (16), 55 (30), 41 (27); 1H
NMR: 7.70–7.40 (m, 5H, Ar), 6.62 (dt, J¼15.4 Hz, J0¼6.6 Hz, 1H, SO2–
CH]CH–), 6.23 (dt, J¼15.4 Hz, J0¼1.5 Hz, 1H, SO2–CH]CH–), 2.22
(dtd, J¼7.3 Hz, J0¼7.4 Hz, J00¼1.6 Hz, 2H, –CH]CH–CH2), 1.50–1.20
(m, 8H, CH]CH–CH2–(CH2)4–CH3), 0.86 (t, J¼6.6 Hz, 3H, CH2–CH3);
13C NMR: 144.0, 141.3, 134.7, 130.6 (2C), 129.1 (2C), 124.2, 31.8, 31.3,
28.5, 27.8, 22.3, 13.8; IR (cmꢃ1): 3048, 2950, 2912, 2873, 2337, 1623,
1593, 1458, 1312, 1287, 1146, 978, 807. Anal. Calcd for C14H20O2S: C,
66.63; H, 7.99; O, 12.68; S, 12.71%. Found: C, 66.61; H, 8.01; S,
12.74%.
4.6.1. 1-((E)-Hex-1-enylsulfonyl)-4-methylbenzene (1)
Hexane/ethyl acetate 80:20; yellowish oil; GC–MS (m/z, I%): 238
(Mꢂþ,42), 223 (2), 209 (100), 157 (50), 139 (59), 91 (54), 82 (33), 67
(30); 1H NMR 7.75 (d, J¼7.7 Hz, 2H, o-Ar), 7.32 (d, J¼7.7 Hz, 2H, m-
Ar), 6.96 (dt, J¼15, 6.7 Hz, 1H, SO2–CH]CH–), 6.29 (dt, J¼15 Hz,
J0¼1.5 Hz, 1H, SO2–CH]CH), 2.43 (s, 3 Hz, Ar–CH3), 2.22 (dtd,
J¼6.7 Hz, J0¼6.7 Hz, J00¼1.5 Hz, CH]CH–CH2), 1.40–1.20 (m, 4H,
CH2–CH2–CH2–CH3), 0.89 (t, J¼7.3 Hz, 3H, CH2–CH3); 13C NMR:
146.8, 144.3, 138.1 (2C), 133.2 (2C), 130.9, 127.8, 31.4, 29.9, 22.3, 21.8,
13.9; IR (cmꢃ1): 3044, 2956, 2922, 2867, 2344, 1628, 1594, 1456,
1317, 1283, 1144, 1083, 972, 833, 811, 655. Anal. Calcd for C13H18O2S:
C, 65.51; H, 7.61; O, 13.43; S, 13.45%. Found: C, 65.54; H, 7.59; S,
13.42%.
4.6.7. 1-((E)-Hex-1-enylsulfonyl)biphenyl (7)
Hexane/ethyl acetate 80:20; yellowish oil; GC–MS (m/z, I%): 300
(Mꢂþ, 100), 271 (5), 245 (5), 217 (10), 201 (80), 169 (67), 152 (79), 141
(16); 1H NMR: 8.05–7.95 (m, 2H, o-SO2Ar), 7.85–7.80 (m, 2H, m-
SO2Ar), 7.75–7.65 (m, 2H, o-Ph), 7.60–7.50 (m, 3H, mþp-Ph), 7.11 (dt,
J¼15 Hz, J0¼6.6 Hz, 1H, SO2–CH]CH–), 6.44 (dt, J¼15 Hz, J0¼1.5 Hz,
1H, SO2–CH]CH–), 2.34 (dtd, J¼6.6 Hz, J0¼7.0 Hz, J00¼1.5 Hz,
CH]CH–CH2–), 1.60–1.30 (m, 4H, CH2–(CH2)2–CH3), 0.98 (t,
J¼7.0 Hz, 3H, CH2–CH3); 13C NMR: 147.5, 146.4, 139.6, 139.5, 130.7
(2C), 129.3 (2C), 128.8 (2C), 128.3 (2C), 128.1, 127.6, 31.5, 29.9, 22.4,
14.0; IR (cmꢃ1): 3033, 2922, 2355, 1622, 1594, 1500, 1450, 1405,
1322, 1283, 1144, 1073, 956, 811, 750, 700, 657, 570, 528. Anal. Calcd
for C18H20O2S: C, 71.96; H, 6.71; O, 10.65; S, 10.67%. Found: C, 71.93;
H, 6.73; S, 10.65%.
4.6.2. 1-((E)-2-Cyclohexylvinylsulfonyl)-4-methylbenzene (2)
Hexane/ethyl acetate 80:20; yellowish oil; GC–MS (m/z, I%): 264
(Mꢂþ, 11), 207 (5), 183 (24), 157 (16), 139 (26), 109 (100), 91 (33), 79
(29), 67 (53); 1H NMR: 7.74 (d, J¼8.1 Hz, 2H, o-Ar), 7.32 (d, J¼8.1 Hz,
2H, m-Ar), 6.92 (dd, J¼15.5 Hz, J0¼6.2 Hz, 1H, SO2–CH]CH–), 6.22
(dd, J¼15.5 Hz, J0¼1.5 Hz, 1H, SO2–CH]CH–), 2.43 (s, 3H, Ar-CH3),
2.10–2.20 (m,1H, CH]CH–CHo),1.85–1.65 (m, 5H, c-Hex),1.30–1.10
(m, 5H, c-Hex); 13C NMR: 146.1, 144.4, 138.1, 130.1(2C), 127.8(2C),
127.0, 39.1, 34.3, 28.6, 28.4, 21.8; IR (cmꢃ1): 2922, 2844, 1627, 1594,
1444, 1322, 1294, 1277, 1138, 1083, 972, 833, 811, 667, 544. Anal.
Calcd for C15H20O2S: C, 68.14; H, 7.62; O, 12.10; S, 12.13%. Found: C,
68.10; H, 7.65; S, 12.16%.
4.6.8. 1-(2-Methylbutylsulfonyl)-4-methylbenzene (8)
4.6.3. 1-((E)-3,3-Dimethylbut-1-enylsulfonyl)-4-methylbenzene (3)
Hexane/ethyl acetate 80:20; yellowish oil; GC–MS (m/z, I%): 238
(Mꢂþ, 3), 223 (1), 157 (8), 139 (31), 91 (20), 83 (100), 67 (16), 55 (26);
1H NMR: 7.75 (d, J¼8.1 Hz, 2H, o-Ar), 7.33 (d, J¼8.1 Hz, 2H, m-Ar),
6.92 (d, J¼15 Hz, 1H, SO2–CH]CH–), 6.18 (d, J¼15 Hz, 1H, SO2–
CH]CH), 2.44 (s, 3H, Ar–CH3), 1.08 (s, 9H, C(–CH3)3); 13C NMR:
146.1, 144.3, 140.1, 133.5, 130.1 (2C), 127.8 (2C), 34.3, 28.6, 21.8 (3C);
IR (cmꢃ1): 2967, 2856, 2356, 1617, 1594, 1461, 1361, 1311, 1289, 1178,
1139, 1093, 978, 917, 833, 806, 756. Anal. Calcd for C13H18O2S: C,
65.51; H, 7.61; O,13.43; S,13.45%. Found: C, 65.48; H, 7.64; S,13.40%.
Hexane/ethyl acetate 80:20; yellowish oil; GC–MS (m/z, I%): 207
(2), 173 (22), 155 (72), 91 (79), 70 (100); 1H NMR: 7.87 (d, J¼8.0 Hz,
2H, o-Ar), 7.42 (d, J¼8.0 Hz, 2H, m-Ar), 3.97 (dd, J¼9.2 Hz, J0¼6.2 Hz,
1H, SO2–CH2–CH), 3.88 (dd, J¼9.2 Hz, J0¼6.2 Hz, 1H, SO2–CH2–CH),
2.42 (s, 3H, Ar–CH3), 1.40–1.30 (m,1H, SO2–CH2–CHo),1.30–1.20 (m,
2H, –CH–CH2–CH3), 0.96 (d, J¼6.5 Hz, 3H, CH–CH3), 0.90 (t,
J¼7.3 Hz, 3H, CH2–CH3); 13C NMR: 130.5, 130.0 (2C), 128.1 (2C),
127.3, 75.1, 34.6, 25.7, 21.9, 16.2, 11.2; IR (cmꢃ1): 2956, 2922, 2867,
2356, 1594, 1461, 2478, 1189, 1172, 1094, 961, 844, 811, 783, 661.
Anal. Calcd for: C12H18O2S: C, 63.68; H, 8.02; O, 14.14; S, 14.17%.
Found: C, 63.71; H, 8.00; S, 14.15%.
4.6.4. 1-((E)-4Tosylbut-3-enyl)benzene (4)
Hexane/ethyl acetate 80:20; white solid mp 42–45 ꢁC; GC–MS
(m/z, I%): 285 (Mꢃ1ꢂþ, 1), 157 (2), 130 (40), 115 (3), 91 (100), 77 (3),
Acknowledgements
1
65 (10); H NMR: 7.95 (dt, J¼8.4 Hz, J0¼1.8 Hz, 2H, o-ArSO2), 7.45–
The authors thank Mr. M. Martinelli for technical assistance.
References and notes
7.15 (m, 7H, Ar), 7.06 (dt, J¼15.0 Hz, J0¼6.9 Hz, 1H, SO2–CH]CH–),
6.37 (dt, J¼15.0 Hz, J0¼1.5 Hz, 1H, SO2–CH]CH–), 2.86 (t, J¼7.0 Hz,
2H, CH2–CH2–Ph), 2.63 (dtd, J¼7.0 Hz, J0¼6.9 Hz, J00¼1.5 Hz, 2H,
CH2–CH2–Ph), 2.46 (s, 3H, Ar–CH3); 13C NMR: 145.4, 144.2, 140.1,
137.7, 131.4, 129.9 (2C), 128.6 (2C), 128.4 (2C), 127.6 (2C), 126.4, 33.9,
33.1, 21.6; IR (cmꢃ1): 2934, 2827, 1632, 1600, 1450, 1318, 1290, 1270,
1130, 1067, 982, 843, 801, 672, 538. Anal. Calcd for C17H18O2S: C,
71.30; H, 6.34; O, 11.17; S, 11.20%. Found: C, 71.35; H, 6.32; S, 11.18%.
1. Nayera, C.; Yus, M. Tetrahedron 1999, 55, 10547.
2. Fabre, J.-L.; Julia, M.; Verpeaux, J.-N. Bull. Soc. Chim. Fr. 1985, 762.
3. Trost, B. M.; Ghadiri, M. R. J. Am. Chem. Soc. 1986, 108, 1098.
4. Otera, J.; Misawa, H.; Sugimoto, K. J. Org. Chem. 1986, 51, 3830.
5. Keck, G. E.; Savin, K. A.; Weglarz, M. A. J. Org. Chem. 1995, 60, 3194.
6. Alonso, I.; Carretero, J. C.; Garrido, J. L.; Magro, V.; Pedregal, C. J. Org. Chem. 1997,
62, 5682.
7. Block, E.; Jeon, H. R.; Zhang, S.-Z.; Dikarev, E. V. Org. Lett. 2004, 6, 437.
8. Yoshimatsu, M.; Kawahigashi, M.; Hondab, E.; Kataoka, T. J. Chem. Soc., Perkin
Trans. 1 1997, 695.
9. Kim, S. H.; Jin, Z.; Ma, S.; Fuchs, P. L. Tetrahedron Lett. 1995, 36, 4013.
10. Yoshimatsu, M.; Hayashi, M.; Tanabe, G.; Muraoka, O. Tetrahedron Lett. 1996, 37,
4161.
4.6.5. (E)-1-(Methylsulfonyl)hex-1-ene (5)
Hexane/ethyl acetate 50:50; yellowish oil; GC–MS (m/z, I%): 162
(Mꢂþ, 100), 143 (21), 125 (8), 111 (43), 97 (76), 83 (51), 69 (93), 55
1
(97), 41 (40); H NMR: 7.02 (dt, J¼14.8 Hz, J0¼6.6 Hz, 1H, SO2–

G. Signore et al. / Tetrahedron 64 (2008) 11218–11223
11223
11. Hopkins, P. B.; Fuchs, P. L. J. Org. Chem. 1978, 43, 1208.
12. Backer, H. J.; Strating, J. Recl. Trav. Chim. Pays-Bas 1954, 73, 565.
13. Back, T. G. Tetrahedron 2001, 57, 5263.
14. Corlay, H.; Lewis, R. T.; Motherwell, W. B.; Shipman, M. Tetrahedron 1995, 51,
3303.
15. Michrowska, A.; Bieniek, M.; Kim, M.; Klajn, R.; Grela, K. Tetrahedron 2003, 59,
4525.
16. Kleijn, H.; Vermeer, P. J. Org. Chem. 1985, 50, 5143.
17. Ryu, I.; Matsumoto, K.; Kameyama, Y.; Ando, M.; Kusumoto, N.; Ogawa, A.;
Kambe, N.; Murai, S.; Sonoda, N. J. Am. Chem. Soc. 1993, 115, 12330.
18. Eisch, J. J.; Behrooz, M.; Dua, S. K. J. Organomet. Chem. 1985, 285, 121.
19. Truce, W.; Wolf, G. C. J. Org. Chem. 1971, 36, 1727.
20. Amiel, Y. J. Org. Chem. 1971, 36, 3691.
23. Hershberger, J.; Russell, G. A. Synthesis 1980, 475.
24. Truce, W. E.; Goralsky, C. T. J. Org. Chem. 1971, 36, 3697.
25. Asscher, M.; Vofsi, D. J. Chem. Soc. 1964, 4962.
26. Sas, W. J. Chem. Soc., Chem. Commun. 1984, 862.
27. Tanikaga, R.; Tamura, T.; Nozaki, Y.; Kaji, A. J. Chem. Soc., Chem. Commun. 1984,
87.
28. Mohamed Zahouily, M.; Salah, M.; Bennazha, J.; Rayadha, A.; Sebti, S. Tetrahe-
dron Lett. 2003, 44, 3255.
29. Signore, G.; Samaritani, S.; Malanga, C.; Menicagli, R. Synthesis 2006, 762.
30. Signore, G.; Calderisi, M.; Malanga, C.; Menicagli, R. Tetrahedron 2007, 63, 177.
31. Signore, G.; Malanga, C.; Menicagli, R. Tetrahedron 2008, 64, 197.
32. Truce, W. E.; Goralski, C. T.; Christensen, L. W.; Bavry, R. H. J. Org. Chem. 1970, 35,
4217.
21. Labadie, S. S. J. Org. Chem. 1989, 54, 2496.
33. Amiel, Y. Tetrahedron Lett. 1971, 12, 661.
22. Duan, D.-H.; Huang, X. Synlett 1999, 317.
34. Higashi, F.; Ikeda, E. Macromol. Rapid Commun. 2000, 21, 1306.