Coupling reaction of magnesium alkylidene carbenoids with α-sulfonylallyllithiums: An efficient route to multi-substituted vinylallenes

Article abstract of DOI:10.1055/s-0032-1317507

A variety of vinylallenes were successfully synthesized from 1-chlorovinyl p-tolyl sulfoxides and allyl or vinyl sulfones. Allyl and vinyl sulfones served as α-sulfonylallyllithium sources were prepared from carbonyl compounds in three or four steps in good overall yields. The coupling reaction of α-sulfonylallyllithiums with magnesium alkylidene carbenoids, which were generated from 1-chlorovinyl p-tolyl sulfoxides and isopropylmagnesium chloride, afforded multi-substituted vinylallenes in up to 88% yield. Georg Thieme Verlag KG Stuttgart · New York.

Full text of DOI:10.1055/s-0032-1317507

PAPER
▌3623
paper
Coupling Reaction of Magnesium Alkylidene Carbenoids with α-Sulfonyl-
allyllithiums: An Efficient Route to Multi-Substituted Vinylallenes
Coupling of Mg Alkylidene Carbenoids with α-Sulfonylallyllithiums
Tsutomu Kimura,a Gen Kobayashi,b Masashi Ishigaki,b Mio Inumaru,b Jo Sakurada,b Tsuyoshi Satoh*a,b
a
Department of Chemistry, Faculty of Science, Tokyo University of Science, 12 Ichigaya-funagawara-machi, Shinjuku-ku, Tokyo 162-0826,
Japan
b
Graduate School of Chemical Sciences and Technology, Tokyo University of Science, 12 Ichigaya-funagawara-machi, Shinjuku-ku,
Tokyo 162-0826, Japan
Fax +81(3)52614631; E-mail: tsatoh@rs.kagu.tus.ac.jp
Received: 30.08.2012; Accepted after revision: 06.10.2012
dene carbenoids with α-sulfonylallyllithiums, that is, if
Abstract: A variety of vinylallenes were successfully synthesized
vinylidene components could be coupled with allylidene
from 1-chlorovinyl p-tolyl sulfoxides and allyl or vinyl sulfones.
components through a double bond,8 we reasoned that it
would be an efficient route to vinylallenes (Scheme 1,
Allyl and vinyl sulfones served as α-sulfonylallyllithium sources
were prepared from carbonyl compounds in three or four steps in
good overall yields. The coupling reaction of α-sulfonylallyllithi- equation 3). Herein, we report the synthesis of multi-
ums with magnesium alkylidene carbenoids, which were generated
from 1-chlorovinyl p-tolyl sulfoxides and isopropylmagnesium
chloride, afforded multi-substituted vinylallenes in up to 88% yield.
substituted vinylallenes from 1-chlorovinyl sulfoxides
and allyl sulfones as well as vinyl sulfones.
Key words: vinylallenes, magnesium alkylidene carbenoids, allyl
sulfones, vinyl sulfones, 1-chlorovinyl p-tolyl sulfoxides, coupling
O
O
Li
R4
S
R2
Ar
R2
R3
MgCl
R1
R4
(1)
R10 (2)
(3)
•
R1
Vinylallenes, also referred to as 1,2,4-trienes, are a class
of conjugated compounds consisting of allene and alkene
units. They have attracted much attention in recent years
because of their excellent synthetic utilities, especially as
dienes for cycloaddition reactions.1,2 A classical method
for their synthesis is based on the SN2′ reaction of organo-
metallic reagents with 1,4-enynes bearing a leaving group
at the 3-position.3,4 A drawback of this approach is associ-
ated with the regioselectivity of the reaction, which is
caused by the presence of multiple reactive sites in the
enyne substrates.3c,e Considering the above-mentioned
limitations, there is a need for an alternative route for the
preparation of vinylallenes.
Cl
R3
O
O
Li
R7
S
R6
Ar
R6
R10
R5
R8
R7
R5
R9
MgCl
R8
Cl
R9
O
O
Li
R7
S
Ar
R10
R2
R8
R2
R9
R1
R7
Previously, we found that nucleophilic substitution pro-
ceeded at the carbenoid carbon atom of magnesium alkyl-
idene carbenoids to give multi-substituted alkenes.5,6
When anionic carbon nucleophiles with a leaving group
on the carbanion center were used in the reaction, β-elim-
ination of intermediates took place to give allenic com-
pounds.6b,c,h For instance, the reaction of magnesium
alkylidene carbenoids with α-sulfonylalkyllithiums af-
forded tri- and tetrasubstituted allenes in moderate yields
(Scheme 1, equation 1).6c Meanwhile, we also found that
α-sulfonylallyllithiums reacted with cyclobutylmagne-
sium carbenoids to give allylidenecyclobutanes (Scheme
1, equation 2).7 If the general concept of these reactions
could be extended to the reaction of magnesium alkyli-
•
R8
MgCl
R1
R10
Cl
R9
Scheme 1 Synthesis of multi-substituted allenes (equation 1), allyl-
idenecyclobutanes (equation 2), and vinylallenes (equation 3) utiliz-
ing magnesium carbenoids and α-sulfonylorganolithiums
We planned to use both allyl p-tolyl sulfones 1 and p-tolyl
vinyl sulfones 2 as precursors for generating α-sulfonylal-
lyllithiums.9 These compounds were readily prepared
from aldehydes or ketones in four or less steps via the dif-
ferent routes presented in Scheme 2. Allyl p-tolyl sulfones
1 were prepared as follows (Scheme 2, equation 1). The
carbonyl compounds were subjected to a Horner–
Wadsworth–Emmons reaction with triethyl phosphono-
acetate to give α,β-unsaturated esters. The esters were re-
duced with DIBAL-H to afford allylic alcohols. The
SYNTHESIS 2012, 44, 3623–3632
Advanced online publication: 24.10.2012
0
0
3
9
-
7
8
8
1
1
4
3
7
-
2
1
0
X
DOI: 10.1055/s-0032-1317507; Art ID: SS-2012-F0694-OP
© Georg Thieme Verlag Stuttgart · New York

3624
T. Kimura et al.
PAPER
allylic alcohols were converted into the corresponding erated from allyl sulfone 1a gave vinylallene 4a in 51%
sulfides, and the sulfides were oxidized with MCPBA to yield (Table 1, entry 1).6c In this reaction, a solution of α-
furnish the requisite allyl p-tolyl sulfones 1.10 When 1,4- sulfonylallyllithium in THF was added to a solution of
dioxaspiro[4.5]decan-8-one was used as the starting mate- magnesium alkylidene carbenoid in THF through a can-
rial, allyl p-tolyl sulfone 1c was obtained in 78% overall nula. The experimental procedure was modified for the
yield. p-Tolyl vinyl sulfones 2 were prepared from car- coupling reaction to forgo these laborious cannula trans-
bonyl compounds and alkyl p-tolyl sulfones (Scheme 2, fers. After several experimentations, it was found that the
equation 2). Nucleophilic addition of the carbanion gener- reaction could proceed when the magnesium alkylidene
ated from alkyl p-tolyl sulfones to carbonyl compounds carbenoid was generated in the presence of α-sulfonylal-
afforded β-hydroxyalkyl sulfones. Subsequent acetylation lyllithium, indicating that the order of addition of the two
of the hydroxy group with acetic anhydride, followed by components was inconsequential. It was also found that
an elimination reaction of the resulting acetate with lithi- using tert-butylmagnesium chloride as an additive im-
um amide, afforded the desired p-tolyl vinyl sulfones 2. proved the yield of the reaction. tert-Butylmagnesium
For example, isocrotyl p-tolyl sulfone (2a) was prepared chloride was not capable of reacting with the sulfoxides 3
from acetone and methyl p-tolyl sulfone in 94% yield over and improved the reaction by minimizing protonation of
three steps.
the magnesium alkylidene carbenoid by trace water in the
reaction media. By our improved protocol, the desired
coupling product 4a was obtained in 57% yield (Table 1,
entry 2).
O
O
P
, NaH
OEt
O
EtO
R2
EtO
DIBAL-H
OEt
To demonstrate the extent of substrate tolerance in this re-
action, various allyl sulfones 1b–h were used for the cou-
pling reaction (Table 1, entries 3–10).11 The reaction of
both acyclic and cyclic 3,3-disubstituted allyl sulfones
1b–d with 1-chlorovinyl p-tolyl sulfoxide 3a proceeded
smoothly under the optimized conditions to give the cor-
responding vinylallenes 4b–d in 66–88% yields (entries
3–5). When geometric isomers of cinnamyl sulfone, (E)-
1e and (Z)-1e, were used in the reaction, styrylallenes (E)-
4e and (Z)-4e were formed without isomerization of the
C=C bond (entries 6 and 7).12 The sulfones 1f and 1g,
which bear a methyl group at the β-position, also reacted
with the sulfoxide 3a to furnish tri- and pentasubstituted
vinylallenes 4f and 4g (entries 8 and 9). However, at-
tempts to synthesize the fully substituted vinylallene 4h
were unsuccessful because of the difficulty in deprotonat-
ing the α-substituted allyl sulfone 1h (entry 10).
R1
R2
O
R1
O
O
1) TolS–STol, Bu3P
2) MCPBA
HO
R2
S
R2
(1)
Tol
R1
R1
1
O
O
O
S
Tol
O
O
78% yield (4 steps)
O
O
1c
O
O
Ac2O
pyridine
DMAP
S
Tol
OH
, LDA
O
O
O
R1
R1
R2
S
R1
R1
Tol
The coupling reaction was applicable to a variety of mag-
nesium alkylidene carbenoids (Table 2).13 1-Chlorovinyl
p-tolyl sulfoxides 3b–d having two alkyl groups including
methyl, ethyl, and 2-phenylethyl groups at the β-position
underwent the reaction with allyl sulfone 1c to give the
corresponding vinylallenes 4i–k in 68–80% yields (Table
2, entries 1–3). The coupling reaction also took place with
cyclic 1-chlorovinyl sulfoxides 3e–g bearing a 5-, 8-, and
15-membered ring to afford vinylallenes 4l–n in 53–85%
yields (entries 4–6). When sulfoxide (Z)-3h, which has
two different substituents at the β-position, was employed
in the reaction, vinylallene 4o was obtained in 63% yield,
whereas the reaction with the other geometric isomer (E)-
3h afforded the same product 4o in lower yield (entries 7
and 8). Presumably, this is due to the difference in reactiv-
ity of the magnesium alkylidene carbenoids toward the
α-sulfonylallyllithium.
R2
O
R1
NLi
OAc
O
O
O
O
R1
R1
S
R1
S
(2)
Tol
Tol
R2
R2
2
O
O
S
O
Tol
94% yield (3 steps)
2a
Scheme 2 Preparation of allyl sulfones 1 and vinyl sulfones 2 (Tol =
4-MeC6H4)
With two types of α-sulfonylallyl anion sources in hand,
our attention was turned to the coupling reaction of 1-
chlorovinyl p-tolyl sulfoxides 3 with the sulfones 1 or 2.
In a previous preliminary study, we reported that the reac-
tion of the magnesium alkylidene carbenoid generated
from the sulfoxide 3a with the α-sulfonylallyllithium gen-
The deprotonation of vinyl sulfones 2 was used as an al-
ternative method for the generation of α-sulfonylallyllith-
iums (Table 3). In this reaction, a proton at the γ-position
is abstracted by butyllithium. Considering the difficulty in
deprotonating α-substituted allylsulfones (Table 1, entry
Synthesis 2012, 44, 3623–3632
© Georg Thieme Verlag Stuttgart · New York

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Coupling of Magnesium Alkylidene Carbenoids with α-Sulfonylallyllithiums
3625
Table 1 Synthesis of Vinylallenes 4a–h from Allyl Sulfones 1 and Sulfoxide 3a
O
O
R2
O
S
O
O
BuLi
i-PrMgCl
O
R2
O
S
R4
+
Tol
Tol
•
R4
R1
R3
THF
–78 to 0 °C
Cl
R1
R3
3a
1
4a–h
Entry
1a
Allyl sulfone 1 R1
R2
H
H
H
R3
H
R4
H
Vinylallene 4
Yield of 4 (%)
1a
1a
1b
H
H
H
4a
4a
4b
51
57
73
2b
H
H
3b
Me
Me
O
O
S
Tol
4b
1c
4c
88
O
O
5b
6b
7b
8b
1d
H
H
H
H
H
Ph
H
Ph
Ph
H
4d
66
72
68
74
(E)-1e
(Z)-1e
1f
H
(E)-4e
(Z)-4e
4f
H
Ph
H
Me
H
O
O
S
Tol
9b
1g
4g
68
O
O
10b,c
1h
Me
Me
Me
Me
4h
0
a A solution of α-sulfonylallyllithium in THF was added to a solution of magnesium alkylidene carbenoid in THF through a cannula.
b Magnesium alkylidene carbenoid was generated from sulfoxide 3a in the presence of α-sulfonylallyllithium.
c t-BuLi was used as a base instead of BuLi.
10), this method is particularly suitable for generating α- age at 25 °C. When vinylallene 4a was kept at 40 °C, it
substituted α-sulfonylallyllithiums. As expected, the cou- decomposed completely within three hours. Diluted solu-
pling reaction of acyclic and cyclic vinyl sulfones 2a–d tions of vinylallenes decomposed over longer time peri-
with sulfoxide 3a gave a variety of vinylallenes 4f and ods than neat samples. A solution of vinylallene 4a in
4p–r in 64–79% yields (Table 3, entries 1–4). Vinylal- CHCl3 gradually degraded, and 41% of vinylallene 4a re-
lenes 4s and 4t bearing a substituent at the 3-position were mained after five days of storage at 25 °C. When a solu-
obtained from α-substituted vinyl sulfones 2e and 2f in tion of vinylallene 4a was stored at 0 °C for three weeks,
82% and 75% yield, respectively (entries 5 and 6). Vinyl 65% of vinylallene 4a could be recovered from the result-
sulfone 2g bearing a tert-butoxycarbonyl group at the ing messy sample.
α-position could also be used as the coupling partner, al-
A plausible mechanism for the coupling reaction is shown
though the yield of the product 4u was far from satisfac-
in Scheme 3. First, an α-sulfonylallyllithium is generated
tory due to the low nucleophilicity of the resulting
from allyl sulfone 1 or vinyl sulfone 2 and butyllithium.
Once the magnesium alkylidene carbenoid has been gen-
carbanion (entry 7).
In the 13C NMR spectra of vinylallenes 4, the signals cor- erated from 1-chlorovinyl p-tolyl sulfoxide 3 and isopro-
responding to allenic carbon atoms were observed in the pylmagnesium chloride by a sulfoxides–magnesium
range of 200 to 204 ppm, and characteristic IR absorptions exchange reaction,5 nucleophilic substitution of the result-
of allenes 4 were observed at 1939–1952 cm–1. Over short ing magnesium alkylidene carbenoid with the α-sulfonyl-
periods of time, vinylallenes 4 were sufficiently stable in allyllithium takes place at the carbenoid carbon atom to
air at room temperature and could be purified by column give intermediate 5.14,15 Magnesium 4-methylbenzenesul-
chromatography on silica gel. However, these compounds finate chloride is lost from intermediate 5 to form vinylal-
were not stable during long-term storage. For example, lene 4.
88% of vinylallene 4a decomposed after five days of stor-
© Georg Thieme Verlag Stuttgart · New York
Synthesis 2012, 44, 3623–3632

3626
T. Kimura et al.
PAPER
Table 2 Synthesis of Vinylallenes 4i–o from Allyl Sulfone 1c and Sulfoxides 3b–h
R2
R2
O
S
O
O
R1
•
BuLi
S
i-PrMgCl
R1
Tol
Tol
+
O
O
Cl
THF
–78 to 0 °C
O
O
3b–h
1c
4i–o
Entry
Sulfoxide 3
R1
Me
Et
R2
Me
Et
Vinylallene 4
Yield of 4 (%)
1
2
3
3b
3c
3d
4i
78
68
80
4j
4k
PhCH2CH2
PhCH2CH2
O
S
4
5
3e
3f
4l
85
67
Tol
Cl
O
S
4m
Tol
Cl
O
6
3g
4n
53
S
Tol
Cl
7
8
(E)-3h
(Z)-3h
Me
n-C5H11
n-C5H11
4o
4o
49
63
Me
In summary, we have developed an efficient method for
the synthesis of multi-substituted vinylallenes. The pres-
ent strategy enabled us to combine two different coupling
partners, the vinylidene and allylidene synthons, via the
C=C bond without homocoupling products. We were able
to use both allyl and vinyl sulfones as α-sulfonylallyl
anion sources, which is a strength of our strategy as both
classes of compounds could be readily prepared from di-
verse aldehydes and ketones. Further studies on the appli-
cations of magnesium alkylidene carbenoids as
vinylidene building blocks are in progress and will be re-
ported in due course.
deprotonation
BuLi
1
2
deprotonation
BuLi
O
O
S
Tol
R3
R6
Li
sulfoxide–
magnesium
exchange
reaction
R2
R2
R4
Cl
Cl
R5
R1
i-PrMgCl
R1
S
MgCl
Melting points were measured using a Yanaco MP-S3 apparatus
and are uncorrected. NMR spectra were measured in a CDCl3 solu-
tion with Jeol JNM-LA 300, Jeol JNM-LA 500, Bruker DPX 300,
Bruker DPX 400, and Bruker AV 600 spectrometers. Mass spectra
(MS) were obtained at 70 eV by direct injection with a Hitachi M-
80B mass spectrometer. IR spectra were recorded on a PerkinElmer
Spectrum One FTIR instrument. Silica gel 60 N (Kanto Chemical)
containing 0.5% fluorescence reagent 254 and a quartz column
were used for column chromatography, and the products having UV
absorption were detected by UV irradiation. Anhyd THF was pur-
chased from Kanto Chemical Co., Inc. and used as supplied. Tolu-
ene was distilled from CaH2. All reactions involving air- or water-
sensitive compounds were routinely conducted in glassware that
had been flame-dried under a positive pressure of argon. 1-Chloro-
vinyl p-tolyl sulfoxides 3 were prepared according to the procedure
O
Tol
O
3
R2
ClMg
O
S
Tol
R3
R6
R2
R1
•
R3
R5
β-elimination
– TolS(O)OMgCl
R1
R4
R6
R4
R5
5
4
Scheme 3 A plausible mechanism for the reaction of magnesium
alkylidene carbenoids with α-sulfonylallyllithiums
Synthesis 2012, 44, 3623–3632
© Georg Thieme Verlag Stuttgart · New York

PAPER
Coupling of Magnesium Alkylidene Carbenoids with α-Sulfonylallyllithiums
3627
M soln of DIBAL-H in hexane (20.6 mL, 21.0 mmol) was added to
a soln of ethyl 2-(1,4-dioxaspiro[4.5]decan-8-ylidene)acetate (2.25
g, 9.94 mmol) in toluene (20 mL) at –78 °C, and the reaction mix-
ture was stirred at–78 °C for 5 min. The reaction was quenched with
sat. aq potassium sodium tartrate (20 mL), and the mixture was ex-
tracted with CHCl3 (3 × 20 mL). The combined organic layers were
dried (MgSO4) and concentrated under reduced pressure. The resi-
due was purified by column chromatography on silica gel [Rf = 0.45
(hexane–EtOAc, 1:1)] to give 2-(1,4-dioxaspiro[4.5]decan-8-yli-
dene)ethanol (1.77 g, 9.61 mmol, 97%) as a colorless oil. Bu3P
(2.75 g, 13.6 mmol) was added to a soln of 2-(1,4-dioxaspi-
ro[4.5]decan-8-ylidene)ethanol (1.77 g, 9.61 mmol) and (4-
MeC6H4S)2 (3.10 g, 12.6 mmol) in THF (35 mL) at 0 °C, and the re-
action mixture was stirred at 25 °C for 12 h. Aq NaOH (5%, 10 mL)
was added to the reaction mixture, and the mixture was extracted
with toluene (3 × 15 mL). The combined organic layers were dried
(MgSO4) and concentrated under reduced pressure. The residue was
purified by column chromatography on silica gel [Rf = 0.20 (hex-
ane–EtOAc, 10:1)] to give 8-[2-(p-tolylthio)ethylidene]-1,4-dioxa-
spiro[4.5]decane (2.64 g, 9.09 mmol, 95%) as a colorless oil.
MCPBA (with approximately 25% H2O, 2.07 g, 9.0 mmol) was
added to a soln of 8-[2-(p-tolylthio)ethylidene]-1,4-dioxaspi-
ro[4.5]decane (1.25 g, 4.30 mmol) in CHCl3 (20 mL) at 0 °C over a
period of 20 min, and the reaction mixture was stirred at 0 °C for 1
h. The reaction was quenched with sat. aq Na2SO3 (7.5 mL), and the
mixture was extracted with CHCl3 (3 × 10 mL). The combined or-
ganic layers were dried (MgSO4) and concentrated under reduced
pressure. The residue was purified by column chromatography on
silica gel [Rf = 0.21 (hexane–EtOAc, 2:1)] to give 1c (1.17 g, 3.63
mmol, 84%) as colorless crystals; mp 120.1–121.0 °C.
Table 3 Synthesis of Vinylallenes 4f,p–u from Vinyl Sulfones 2 and
Sulfoxide 3a
O
O
O
S
O
Tol
BuLi
i-PrMgCl
R2
Cl
O
3a
•
R2
THF
–78 to 0 °C
+
R2
R1
4f,p–u
O
O
S
R2
Tol
R1
2
Entry Vinyl sulfone 2
Vinylallene 4
Yield of
4 (%)
O
O
1
2
2a
2b
4f
74
64
•
S
Tol
O
O
O
O
•
4p
S
S
Tol
Tol
3
2c
4q
4r
68
79
•
IR (KBr): 2961, 2923, 1597, 1444, 1311, 1296, 1144, 1123, 1085,
1031, 904, 863, 812, 756, 746 cm–1.
O
O
O
O
4a
2d
•
•
S
S
Tol
Tol
1H NMR (300 MHz, CDCl3): δ = 1.29 (br t, J = 6.7 Hz, 2 H), 1.60
(br t, J = 6.7 Hz, 2 H), 1.96 (br t, J = 6.7 Hz, 2 H), 2.24 (br t, J = 6.7
Hz, 2 H), 2.45 (s, 3 H), 3.80 (d, J = 8.0 Hz, 2 H), 3.88–3.94 (m, 4
H), 5.21 (br t, J = 8.0 Hz, 1 H), 7.33 (d, J = 8.1 Hz, 2 H), 7.73 (d,
J = 8.1 Hz, 2 H).
MS (EI): m/z (%) = 322 (M+, 2), 167 (100), 123 (27), 105 (20), 91
(13), 86 (13).
5
6
2e
2f
4s
4t
82
75
O
O
O
O
•
S
S
Tol
HRMS (EI): m/z [M+] calcd for C17H22O4S: 322.1239; found:
322.1238.
PMB
PMB
•
(3-Tosylprop-1-ene-1,1-diyl)dibenzene (1d)
Yield: 2.51 g (71%); colorless crystals; mp 128.1–128.9 °C.
7a
2g
4u
30
Tol
t-BuO
O
t-BuO
O
IR (KBr): 2967, 2923, 1595, 1490, 1445, 1314, 1290, 1226, 1167,
1133, 1084, 888, 774, 749, 709, 700, 640 cm–1.
1H NMR (300 MHz, CDCl3): δ = 2.44 (s, 3 H), 3.90 (d, J = 7.9 Hz,
2 H), 6.13 (t, J = 7.9 Hz, 1 H), 6.67–6.73 (m, 2 H), 7.14–7.32 (m, 10
H), 7.66 (d, J = 8.2 Hz, 2 H).
a LDA was used as a base instead of BuLi.
MS (EI): m/z (%) = 348 (M+, 1), 193 (100), 178 (15), 115 (36), 91
(14).
HRMS (EI): m/z [M+] calcd for C22H20O2S: 348.1184; found:
described in the literature.6a,c,e,16 Allyl p-tolyl sulfones 1a,17a 1b,17b
(E)-1e,17c and 1f,17b p-tolyl vinyl sulfones 2a,18a 2b,9c and 2e,18b and
vinylallene 4a6c are known compounds.
348.1181.
8-(2-Tosylethylidene)-1,4-dioxaspiro[4.5]decane (1c); Typical
Procedure
(Z)-1-Methyl-4-[(3-phenylallyl)sulfonyl]benzene [(Z)-1e]
Yield: 393.3 mg (14%); colorless crystals; mp 71.6–72.2 °C.
Triethyl phosphonoacetate (3.84 g, 17.1 mmol) was added dropwise
to a suspension of NaH (dispersion in paraffin liquid, 55%, 660 mg,
15 mmol) in THF (15 mL) at 0 °C, and the mixture was stirred at
25 °C for 30 min. A soln of 1,4-dioxaspiro[4.5]decan-8-one (1.56 g,
10.0 mmol) in THF (5.0 mL) was added to the resulting soln at 0 °C,
and the reaction mixture was stirred at 25 °C for 10 min. The reac-
tion was quenched with H2O (15 mL), and the mixture was extract-
ed with CHCl3 (3 × 20 mL). The combined organic layers were
dried (MgSO4) and concentrated under reduced pressure. The resi-
due was purified by column chromatography on silica gel [Rf = 0.28
(hexane–EtOAc, 3:1)] to give ethyl 2-(1,4-dioxaspiro[4.5]decan-8-
ylidene)acetate (2.25 g, 9.94 mmol, 99%) as a colorless oil. A 1.02
IR (KBr): 3023, 2910, 1593, 1447, 1393, 1311, 1302, 1290, 1167,
1131, 1084, 901, 767, 698, 661 cm–1.
1H NMR (500 MHz, CDCl3): δ = 2.44 (s, 3 H), 4.03 (d, J = 7.8 Hz,
2 H), 5.71 (td, J = 7.8, 11.4 Hz, 1 H), 6.79 (d, J = 11.4 Hz, 1 H),
6.99–7.02 (m, 2 H), 7.21–7.28 (m, 3 H), 7.30 (d, J = 8.1 Hz, 2 H),
7.72 (d, J = 8.1 Hz, 2 H).
MS (EI): m/z (%) = 272 (M+, 3), 117 (100), 115 (23), 91 (12).
HRMS (EI): m/z [M+] calcd for C16H16O2S: 272.0871; found:
272.0869.
© Georg Thieme Verlag Stuttgart · New York
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PAPER
8-(1-Tosylpropan-2-ylidene)-1,4-dioxaspiro[4.5]decane (1g)
1H NMR (500 MHz, CDCl3): δ = 1.65 (quint, J = 7.0 Hz, 2 H), 1.75
(quint, J = 7.0 Hz, 2 H), 2.40–2.45 (m, 5 H), 2.79 (br t, J = 6.9 Hz,
2 H), 6.25 (br s, 1 H), 7.32 (d, J = 8.2 Hz, 2 H), 7.79 (d, J = 8.2 Hz,
2 H).
Yield: 2.18 g (43%); colorless crystals; mp 117.9–118.3 °C.
IR (KBr): 2957, 2890, 1595, 1448, 1311, 1303, 1287, 1147, 1116,
1085, 1030, 924, 891, 817, 742, 675 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.36 (br t, J = 6.3 Hz, 2 H), 1.56–
1.63 (m, 2 H), 1.78 (s, 3 H), 1.97 (br t, J = 6.3 Hz, 2 H), 2.28 (br t,
J = 6.3 Hz, 2 H), 2.45 (s, 3 H), 3.89 (s, 2 H), 3.90–3.94 (m, 4 H),
7.33 (d, J = 8.2 Hz, 2 H), 7.74 (d, J = 8.2 Hz, 2 H).
MS (EI): m/z (%) = 336 (M+, 1), 181 (100), 137 (23), 119 (22), 99
(18), 91 (16), 86 (13).
Anal. Calcd for C13H16O2S: C, 66.07; H, 6.82; S, 13.57. Found: C,
65.69; H, 6.80; S, 13.58.
1-[(Cyclohexylidenemethyl)sulfonyl]-4-methylbenzene (2d)
Yield: 510.4 mg (99%); colorless crystals; mp 37.0–37.6 °C.
IR (KBr): 2945, 2936, 2855, 1620, 1443, 1310, 1297, 1288, 1141,
1085, 813, 792 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.50–1.66 (m, 6 H), 2.14 (br t, J =
5.7 Hz, 2 H), 2.41 (s, 3 H), 2.71 (br t, J = 5.7 Hz, 2 H), 6.10–6.13
(m, 1 H), 7.30 (d, J = 8.1 Hz, 2 H), 7.76 (d, J = 8.1 Hz, 2 H).
HRMS (EI): m/z [M+] calcd for C18H24O4S: 336.1395; found:
336.1396.
1-[(3,4-Dimethylpent-3-en-2-yl)sulfonyl]-4-methylbenzene (1h)
Yield: 378.9 mg (15%); colorless crystals; mp 97.3–98.2 °C.
Anal. Calcd for C14H18O2S: C, 67.16; H, 7.25; S, 12.81. Found: C,
66.83; H, 7.21; S, 12.78.
IR (KBr): 2978, 2922, 1595, 1452, 1305, 1286, 1240, 1142, 1085,
818, 729, 659 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.23–1.27 (m, 3 H), 1.49 (d, J =
7.0 Hz, 3 H), 1.59 (s, 3 H), 1.72 (s, 3 H), 2.44 (s, 3 H), 4.20 (q, J =
7.0 Hz, 2 H), 7.29 (d, J = 8.2 Hz, 2 H), 7.69 (d, J = 8.2 Hz, 2 H).
MS (EI): m/z (%) = 252 (M+, 1), 97 (100), 55 (23).
HRMS (EI): m/z [M+] calcd for C14H20O2S: 252.1184; found:
1-Methoxy-4-(4-methyl-3-tosylpent-3-en-1-yl)benzene (2f)
Yield: 1.58 g (54%); colorless crystals; mp 90.5–91.1 °C.
IR (KBr): 2937, 1633, 1610, 1512, 1457, 1444, 1299, 1245, 1172,
1137, 1085, 1029, 814, 692, 601 cm–1.
1H NMR (500 MHz, CDCl3): δ = 1.78 (s, 3 H), 2.13 (s, 3 H), 2.42
(s, 3 H), 2.64–2.70 (m, 2 H), 2.72–2.78 (m, 2 H), 3.79 (s, 3 H), 6.82
(d, J = 8.5 Hz, 2 H), 7.10 (d, J = 8.5 Hz, 2 H), 7.31 (d, J = 8.3 Hz, 2
H), 7.77 (d, J = 8.3 Hz, 2 H).
MS (EI): m/z (%) = 344 (M+, 16), 121 (100).
HRMS (EI): m/z [M+] calcd for C20H24O3S: 344.1446; found:
252.1183.
1-Methyl-4-[(2-methylprop-1-en-1-yl)sulfonyl]benzene (2a);
Typical Procedure
A 1.65 M soln of BuLi in hexane (4.30 mL, 7.10 mmol) was added
to a soln of i-Pr2NH (0.720 g, 7.12 mmol) in THF (15 mL) at 0 °C,
and the mixture was stirred at 0 °C for 10 min. A soln of 1-methyl-
4-(methylsulfonyl)benzene (1.02 g, 5.99 mmol) in THF (5 mL) was
added dropwise to the resulting soln at –78 °C, and the mixture was
stirred at –78 °C for 10 min. Acetone (0.400 g, 6.89 mmol) was add-
ed to the resulting soln at –78 °C, and the reaction mixture was
stirred at –78 °C for 10 min. The reaction was quenched with sat. aq
NH4Cl (6.0 mL), and the mixture was extracted with CHCl3 (3 × 10
mL). The combined organic layers were dried (MgSO4) and filtered.
Removal of the solvent under reduced pressure gave crude 2-meth-
yl-1-tosylpropan-2-ol (1.35 g) as a colorless oil. 2-Methyl-1-tosyl-
propan-2-ol (1.35 g) was added to a soln of Ac2O (11.9 mL, 126
mmol) in pyridine (24.3 mL, 300 mmol) at 25 °C. DMAP (0.125 g,
1.02 mmol) was added to the resulting soln at 25 °C, and the reac-
tion mixture was stirred at 25 °C for 12 h. After the volatile materi-
als were removed under reduced pressure, the residue was purified
by column chromatography on silica gel [Rf = 0.27 (hexane–EtOAc,
3:1)] to give 2-methyl-1-tosylpropan-2-yl acetate (1.58 g, 5.84
mmol, 97% yield for 2 steps) as colorless crystals. A 1.65 M soln of
BuLi in hexane (10.6 mL, 17.5 mmol) was added to a soln of 2-pi-
peridone (1.74 g, 17.6 mmol) in THF (40 mL) at 0 °C, and the mix-
ture was stirred at 0 °C for 10 min. The resulting soln was added to
a soln of 2-methyl-1-tosylpropan-2-yl acetate (1.58 g, 5.84 mmol)
in THF (20 mL) at 0 °C, and the reaction mixture was stirred at 0 °C
for 30 min. The reaction was quenched with sat. aq NH4Cl (12 mL),
and the mixture was extracted with CHCl3 (3 × 20 mL). The com-
bined organic layers were dried (MgSO4) and concentrated under
reduced pressure. The residue was purified by column chromatog-
raphy on silica gel [Rf = 0.28 (hexane–EtOAc, 3:1)] to give 2a (1.19
g, 5.66 mmol, 97%) as colorless crystals; mp 64.5–65.0 °C (Lit.18a
mp 62–63 °C).
344.1447.
tert-Butyl 3-Methyl-2-tosylbut-2-enoate (2g)
A 2.69 M soln of BuLi in hexane (3.12 mL, 8.39 mmol) was added
to a soln of i-Pr2NH (0.821 g, 8.11 mmol) in THF (10 mL) at 0 °C,
and the mixture was stirred at 0 °C for 10 min. A soln of tert-butyl
2-(p-tolylthio)acetate19 (1.67 g, 7.01 mmol) in THF (15 mL) was
added dropwise to the resulting soln at –78 °C, and the mixture was
stirred at –78 °C for 10 min. Acetone (0.450 g, 7.75 mmol) was add-
ed to the resulting soln at –78 °C, and the reaction mixture was
stirred at –78 °C for 10 min. The reaction was quenched with sat. aq
NH4Cl (6.0 mL) and the mixture was extracted with CHCl3 (3 × 10
mL). The combined organic layers were dried (MgSO4) and filtered.
Removal of the solvent under reduced pressure gave crude tert-bu-
tyl 3-hydroxy-3-methyl-2-(p-tolylthio)butanoate (1.78 g) as a col-
orless oil. tert-Butyl 3-hydroxy-3-methyl-2-(p-tolylthio)butanoate
(1.78 g) was added to a soln of Ac2O (15.0 mL, 159 mmol) in pyri-
dine (30.0 mL, 371 mmol) at 25 °C. DMAP (0.145 g, 1.19 mmol)
was then added to the resulting soln at 25 °C, and the reaction mix-
ture was stirred at 25 °C for 12 h. After the volatile materials were
removed under reduced pressure, the residue was purified by col-
umn chromatography on silica gel [Rf = 0.20 (hexane–EtOAc,
10:1)] to give tert-butyl 3-acetoxy-3-methyl-2-(p-tolylthio)butano-
ate (1.31 g, 3.87 mmol, 55% yield for 2 steps) as a colorless oil. A
2.69 M soln of BuLi in hexane (7.10 mL, 19.1 mmol) was added to
a soln of 2-piperidone (1.93 g, 19.5 mmol) in THF (50 mL) at 0 °C,
and the mixture was stirred at 0 °C for 10 min. The resulting soln
was added to a soln of tert-butyl 3-acetoxy-3-methyl-2-(p-tolyl-
thio)butanoate (1.31 g, 3.87 mmol) in THF (30 mL) at 0 °C, and the
reaction mixture was stirred at 0 °C for 30 min. The reaction was
quenched with sat. aq NH4Cl (14 mL) and the mixture was extracted
with CHCl3 (3 × 20 mL). The combined organic layers were dried
(MgSO4) and concentrated under reduced pressure. The residue was
purified by column chromatography on silica gel [Rf = 0.28 (hex-
ane–EtOAc, 20:1)] to give tert-butyl 3-methyl-2-(p-tolylthio)but-2-
enoate (0.993 g, 3.57 mmol, 92%) as a colorless oil. MCPBA (with
approximately 25% H2O, 1.72 g, 7.48 mmol) was added to a soln of
tert-butyl 3-methyl-2-(p-tolylthio)but-2-enoate (0.993 g, 3.57
mmol) in CHCl3 (15 mL) at 0 °C over a period of 20 min, and the
reaction mixture was stirred at 0 °C for 1 h. The reaction was
The spectroscopic properties of 2a matched those reported in the lit-
erature.18a
1-[(Cyclopentylidenemethyl)sulfonyl]-4-methylbenzene (2c)
Yield: 1.15 g (98%); colorless crystals; mp 39.0–39.5 °C.
IR (KBr): 2960, 2876, 1633, 1597, 1417, 1329, 1312, 1287, 1147,
1086, 1031, 862, 815 cm–1.
Synthesis 2012, 44, 3623–3632
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Coupling of Magnesium Alkylidene Carbenoids with α-Sulfonylallyllithiums
3629
quenched with sat. aq Na2SO3 (7.5 mL), and the mixture was ex-
tracted with CHCl3 (3 × 10 mL). The combined organic layers were
dried (MgSO4) and concentrated under reduced pressure. The resi-
due was purified by column chromatography on silica gel [Rf = 0.23
(hexane–EtOAc, 2:1)] to give 2g (0.986 g, 3.18 mmol, 89%) as col-
orless crystals; mp 102.5–103.0 °C.
1H NMR (300 MHz, CDCl3): δ = 1.66–1.78 (m, 8 H), 2.26–2.34 (m,
6 H), 2.38 (br t, J = 6.5 Hz, 2 H), 3.96 (s, 4 H), 3.97 (s, 4 H), 5.62
(d, J = 10.8 Hz, 1 H), 5.92 (d of quint, J = 2.1, 10.8 Hz, 1 H).
13C NMR (126 MHz, CDCl3): δ = 25.3 (CH2), 28.6 (CH2), 33.6
(CH2), 35.2 (CH2), 35.3 (CH2), 35.9 (CH2), 64.3 (CH2), 88.3 (CH),
100.8 (C), 108.3 (C), 108.8 (C), 119.0 (CH), 138.3 (C), 201.9 (C).
IR (KBr): 2973, 1720, 1617, 1369, 1317, 1271, 1147, 1086, 1008,
843, 806, 756, 660 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.52 (s, 9 H), 1.92 (s, 3 H), 2.12
(s, 3 H), 2.43 (s, 3 H), 7.32 (d, J = 8.2 Hz, 2 H), 7.89 (d, J = 8.2 Hz,
2 H).
MS (EI): m/z (%) = 318 (M+, 97), 232 (86), 204 (33), 170 (56), 118
(100), 117 (28), 99 (71), 91 (28), 86 (27).
HRMS (EI): m/z [M+] calcd for C19H26O4: 318.1831; found:
318.1829.
8-(4-Methylpenta-1,3-dien-1-ylidene)-1,4-dioxaspiro[4.5]dec-
ane (4b)
Yield: 16.1 mg (73%); colorless oil.
Anal. Calcd for C16H22O4S: C, 61.91; H, 7.14; S, 10.33. Found: C,
61.73; H, 7.06; S, 10.36.
1-Chlorovinyl p-Tolyl Sulfoxides 3
IR (neat): 2954, 2885, 1950 (=•=), 1718, 1441, 1377, 1240, 1217,
1111, 1067, 1032, 905, 757, 668 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.71–1.79 (m, 10 H), 2.26–2.33
(m, 4 H), 3.97 (s, 4 H), 5.60 (d of sept, J = 1.4, 10.7 Hz, 1 H), 5.89
(d of quint, J = 2.1, 10.7 Hz, 1 H).
1-Chlorovinyl p-tolyl sulfoxides 3 were prepared according to the
procedure described in the literature.6a,c,e,16 The physical and analyt-
ical data of new sulfoxides 3c,d are given below.
1-[(1-Chloro-2-ethylbut-1-en-1-yl)sulfinyl]-4-methylbenzene
(3c)
MS (EI): m/z (%) = 220 (M+, 2), 99 (100), 91 (11), 86 (14), 55 (16).
Yield: 438.3 mg (24%); yellow oil.
HRMS of compound 4b could not be measured because of low in-
IR (neat): 2974, 2937, 2875, 1597, 1493, 1462, 1087, 1061, 877,
808 cm–1.
tensity of M+ peak.
1H NMR (500 MHz, CDCl3): δ = 1.08 (t, J = 7.4 Hz, 3 H), 1.22 (t,
J = 7.4 Hz, 3 H), 2.30–2.46 (m, 2 H), 2.41 (s, 3 H), 2.71 (qd, J = 7.4,
14.8 Hz, 1 H), 2.81 (qd, J = 7.4, 14.8 Hz, 1 H), 7.31 (d, J = 8.4 Hz,
2 H), 7.48 (d, J = 8.4 Hz, 2 H).
MS (FAB): m/z (%) = 257 ([M + H]+, 100), 239 (12).
HRMS (FAB): m/z [M + H]+ calcd for C13H18ClOS: 257.0767;
8-(4,4-Diphenylbuta-1,3-dien-1-ylidene)-1,4-dioxaspi-
ro[4.5]decane (4d)
Yield: 22.7 mg (66%); colorless crystals; mp 109.6–110.3 °C.
IR (KBr): 3020, 2951, 2882, 1946 (=•=), 1494, 1445, 1248, 1119,
1066, 1032, 906, 760, 702 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.68–1.83 (m, 4 H), 2.25–2.41 (m,
4 H), 3.97 (s, 4 H), 5.84 (d of quint, J = 2.0, 11.1 Hz, 1 H), 6.53 (d,
J = 11.1 Hz, 1 H), 7.17–7.42 (m, 10 H).
found: 257.0765.
13C NMR (101 MHz, CDCl3): δ = 28.5 (CH2), 35.3 (CH2), 64.36
(CH2), 64.37 (CH2), 91.1 (CH), 100.9 (C), 108.3 (C), 124.7 (CH),
127.1 (CH), 127.2 (CH), 127.3 (CH), 128.1 (CH), 128.3 (CH),
130.4 (CH), 139.6 (C), 140.7 (C), 142.3 (C), 203.9 (C).
MS (EI): m/z (%) = 344 (M+, 60), 242 (84), 230 (54), 209 (95), 207
(100), 178 (55), 165 (51), 153 (99), 105 (95), 99 (91).
{3-[Chloro(p-tolylsulfinyl)methylene]pentane-1,5-diyl}diben-
zene (3d)
Yield: 2.06 g (84%); colorless crystals; mp 66.1–67.1 °C.
IR (KBr): 3024, 2927, 1601, 1495, 1453, 1087, 1054, 889, 804, 747,
710, 695 cm–1.
1H NMR (500 MHz, CDCl3): δ = 2.41 (s, 3 H), 2.62–3.00 (m, 8 H),
7.17 (d, J = 7.4 Hz, 2 H), 7.19–7.30 (m, 10 H), 7.33 (t, J = 7.4 Hz,
2 H).
MS (FAB): m/z (%) = 409 [(M + 1)+, 100], 91 (19).
HRMS (FAB): m/z [(M + 1)+] calcd for C25H26ClOS: 409.1393;
HRMS (EI): m/z [M+] calcd for C24H24O2: 344.1776; found:
344.1779.
(E)-8-(4-Phenylbuta-1,3-dien-1-ylidene)-1,4-dioxaspi-
ro[4.5]decane [(E)-4e]
Yield: 19.3 mg (72%); colorless oil.
found: 409.1388.
IR (neat): 2951, 2882, 1947 (=•=), 1253, 1121, 1063, 1032, 961,
905, 748, 734, 692 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.79 (t, J = 6.5 Hz, 4 H), 2.32–2.39
(m, 4 H), 3.98 (s, 4 H), 5.90 (d of quint, J = 2.0, 10.0 Hz, 1 H), 6.46
(d, J = 15.8 Hz, 1 H), 6.59 (dd, J = 10.0, 15.8 Hz, 1 H), 7.16–7.22
(m, 1 H), 7.26–7.32 (m, 2 H), 7.35–7.40 (m, 2 H).
MS (EI): m/z (%) = 268 (M+, 100), 223 (20), 181 (18), 167 (56), 153
(45), 128 (17), 99 (47), 91 (20).
HRMS (EI): m/z [M+] calcd for C18H20O2: 268.1463; found:
268.1463.
8,8′-(Prop-1-ene-1,3-diylidene)bis(1,4-dioxaspiro[4.5]decane)
(4c); Typical Procedure
A 1.62 M soln of BuLi in hexane (0.185 mL, 0.299 mmol) was add-
ed dropwise to a soln of 1c (96.7 mg, 0.300 mmol) in THF (1.0 mL)
at –78 °C, and the mixture was allowed to warm to –70 °C over a
period of 10 min. A soln of 3a (32.7 mg, 0.100 mmol) in THF (0.5
mL) and a 1.02 M soln of t-BuMgCl in THF (0.098 mL, 0.100
mmol) were added to the resulting soln at –78 °C. A 2.0 M soln of
i-PrMgCl in THF (0.14 mL, 0.28 mmol) was added to the resulting
soln at –78 °C, and the reaction mixture was allowed to warm to
0 °C over a period of 1.5 h. The reaction was quenched with sat. aq
NH4Cl (1.5 mL) and the mixture was extracted with CHCl3 (3 × 5
mL). The combined organic layers were dried (MgSO4) and con-
centrated under reduced pressure. The residue was purified by col-
umn chromatography on silica gel [Rf = 0.18 (hexane–EtOAc,
10:1)] to give 4c as colorless crystals; yield: 28.0 mg (0.0879 mmol,
88%); mp 103.3–104.4 °C.
(Z)-8-(4-Phenylbuta-1,3-dien-1-ylidene)-1,4-dioxaspi-
ro[4.5]decane [(Z)-4e]
Yield: 18.2 mg (68%); colorless oil.
IR (neat): 2951, 2881, 1948 (=•=), 1449, 1430, 1242, 1117, 1077,
1032, 904, 774, 733, 699 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.76 (t, J = 6.4 Hz, 4 H), 2.30–2.38
(m, 4 H), 3.97 (s, 4 H), 6.08 (t, J = 11.4 Hz, 1 H), 6.24–6.32 (m, 1
H), 6.36 (dd, J = 0.8, 11.4 Hz, 1 H), 7.18–7.27 (m, 1 H), 7.28–7.37
(m, 4 H).
IR (KBr): 2952, 2877, 1947 (=•=), 1435, 1271, 1239, 1119, 1078,
1031, 951, 942, 902, 817 cm–1.
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T. Kimura et al.
PAPER
MS (EI): m/z (%) = 268 (M+, 23), 206 (21), 181 (17), 167 (56), 154
(51), 141 (19), 128 (23), 115 (18), 99 (100), 91 (19), 86 (18).
IR (neat): 3026, 2947, 2884, 1943 (=•=), 1603, 1496, 1453, 1271,
1224, 1121, 1099, 1074, 1034, 907, 735, 699 cm–1.
HRMS (EI): m/z [M+] calcd for C18H20O2: 268.1463; found:
268.1466.
1H NMR (300 MHz, CDCl3): δ = 1.66–1.74 (m, 4 H), 2.23–2.40 (m,
8 H), 2.72 (t, J = 7.9 Hz, 4 H), 3.97 (s, 4 H), 5.41 (d, J = 10.9 Hz, 1
H), 6.01 (d of quint, J = 2.8, 10.9 Hz, 1 H), 7.13–7.20 (m, 6 H),
7.22–7.30 (m, 4 H).
MS (EI): m/z (%) = 400 (M+, 56), 309 (46), 247 (62), 209 (37), 169
(30), 105 (29), 99 (28), 91 (100).
8-(3-Methylbuta-1,3-dien-1-ylidene)-1,4-dioxaspiro[4.5]decane
(4f)
Yield: 15.3 mg (74%); colorless oil.
IR (neat): 2950, 2881, 1952 (=•=), 1619, 1441, 1271, 1235, 1117,
1072, 1033, 951, 943, 903, 881 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.68–1.85 (m, 7 H), 2.29–2.36 (m,
4 H), 3.97 (s, 4 H), 4.79–4.82 (m, 1 H), 4.87–4.90 (m, 1 H), 5.79–
5.83 (m, 1 H).
HRMS (EI): m/z [M+] calcd for C28H32O2: 400.2402; found:
400.2405.
8-(3-Cyclopentylideneallylidene)-1,4-dioxaspiro[4.5]decane (4l)
Yield: 21.3 mg (85%); colorless oil.
13C NMR (126 MHz, CDCl3): δ = 19.6 (CH3), 28.6 (CH2), 35.4
(CH2), 64.32 (CH2), 64.35 (CH2), 96.0 (CH), 102.8 (C), 108.2 (C),
112.7 (CH2), 140.1 (C), 200.5 (C).
MS (EI): m/z (%) = 206 (M+, 100), 191 (14), 187 (14), 161 (17), 119
(24), 105 (57), 99 (77), 92 (19), 91 (53), 86 (43), 79 (14), 77 (18).
IR (neat): 2952, 2876, 1946 (=•=), 1436, 1272, 1121, 1096, 1035,
945, 906, 734 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.65–1.73 (m, 8 H), 2.25–2.33 (m,
2 H), 2.33–2.43 (m, 6 H), 3.97 (s, 4 H), 5.64 (d, J = 10.9 Hz, 1 H),
5.98 (d of quint, J = 3.9, 10.9 Hz, 1 H).
HRMS (EI): m/z [M+] calcd for C13H18O2: 206.1307; found:
206.1309.
MS (EI): m/z (%) = 246 (M+, 53), 160 (100), 145 (39), 131 (42), 118
(66), 117 (69), 99 (49), 92 (50), 91 (48).
HRMS (EI): m/z [M+] calcd for C16H22O2: 246.1620; found:
246.1618.
8,8′-(But-1-ene-1,3-diylidene)bis(1,4-dioxaspiro[4.5]decane)
(4g)
Yield: 22.7 mg (68%); colorless oil.
8-(3-Cyclooctylideneallylidene)-1,4-dioxaspiro[4.5]decane (4m)
Yield: 19.3 mg (67%); colorless oil.
IR (neat): 2950, 2882, 1948 (=•=), 1442, 1271, 1246, 1228, 1119,
1069, 1033, 943, 909, 732 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.65–1.81 (m, 11 H), 2.29–2.36
(m, 4 H), 2.37–2.46 (m, 4 H), 3.96–3.98 (m, 8 H), 6.20 (quint, J =
1.9 Hz, 1 H).
MS (EI): m/z (%) = 332 (M+, 38), 246 (14), 218 (21), 184 (19), 132
(45), 101 (24), 99 (100), 86 (26).
IR (neat): 2928, 2854, 1939 (=•=), 1698, 1445, 1271, 1227, 1122,
1105, 1081, 1035, 946, 908, 734 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.49–1.74 (m, 14 H), 2.14–2.22
(m, 4 H), 2.29 (br t, J = 6.6 Hz, 2 H), 2.39 (br t, J = 6.4 Hz, 2 H),
3.97 (s, 4 H), 5.64 (br d, J = 10.9 Hz, 1 H), 5.91 (d of quint, J = 2.0,
10.9 Hz, 1 H).
HRMS (EI): m/z [M+] calcd for C20H28O4: 332.1988; found:
332.1981.
MS (EI): m/z (%) = 288 (M+, 50), 202 (100), 131 (36), 118 (52), 117
(54), 99 (63), 92 (68), 91 (45).
HRMS (EI): m/z [M+] calcd for C19H28O2: 288.2089; found:
288.2086.
8-(4-Methylpenta-2,3-dien-1-ylidene)-1,4-dioxaspiro[4.5]dec-
ane (4i)
Yield: 17.2 mg (78%); colorless oil.
8-(3-Cyclopentadecylideneallylidene)-1,4-dioxaspiro[4.5]dec-
ane (4n)
Yield: 20.6 mg (53%); colorless oil.
IR (neat): 2949, 2881, 1949 (=•=), 1444, 1363, 1272, 1226, 1123,
1105, 1076, 1035, 945, 906, 681 cm–1.
1H NMR (500 MHz, CDCl3): δ = 1.68–1.73 (m, 10 H), 2.29 (br t,
J = 6.5 Hz, 2 H), 2.38 (br t, J = 6.6 Hz, 2 H), 3.97 (s, 4 H), 5.61 (d,
J = 10.9 Hz, 1 H), 5.84–5.90 (d of sept, J = 2.7 Hz, 1 H).
MS (EI): m/z (%) = 220 (M+, 20), 134 (46), 119 (100), 99 (26), 91
(31).
HRMS (EI): m/z [M+] calcd for C14H20O2: 220.1463; found:
220.1462.
IR (neat): 2929, 2856, 1942 (=•=), 1459, 1444, 1271, 1224, 1122,
1100, 1075, 1035, 945, 907, 734 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.25–1.52 (m, 24 H), 1.67–1.74
(m, 4 H), 2.00 (dt, J = 2.4, 6.7 Hz, 4 H), 2.29 (br t, J = 6.3 Hz, 2 H),
2.38 (br t, J = 6.3 Hz, 2 H), 3.97 (s, 4 H), 5.61 (br d, J = 10.9 Hz, 1
H), 5.94 (d of quint, J = 2.4, 10.9 Hz, 1 H).
MS (EI): m/z (%) = 386 (M+, 100), 300 (92), 99 (95).
HRMS (EI): m/z [M+] calcd for C26H42O2: 386.3185; found:
386.3182.
8-(4-Ethylhexa-2,3-dien-1-ylidene)-1,4-dioxaspiro[4.5]decane
(4j)
Yield: 16.8 mg (68%); colorless oil.
8-(4-Methylnona-2,3-dien-1-ylidene)-1,4-dioxaspiro[4.5]dec-
ane (4o)
Yield: 13.6 mg (49%, Table 2, entry 7), 17.6 mg (63%, Table 2, en-
try 8); colorless oil.
IR (neat): 2963, 2878, 1942 (=•=), 1454, 1272, 1225, 1123, 1106,
1078, 1035, 945, 906, 824, 733, 680 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.00 (t, J = 7.4 Hz, 6 H), 1.67–1.74
(m, 4 H), 1.99 (dq, J = 2.9, 7.4 Hz, 4 H), 2.29 (br t, J = 6.4 Hz, 2 H),
2.39 (br t, J = 6.4 Hz, 2 H), 3.97 (s, 4 H), 5.61 (d, J = 10.8 Hz, 1 H),
6.05 (d of quint, J = 2.9, 10.8 Hz, 1 H).
MS (EI): m/z (%) = 248 (M+, 20), 162 (27), 133 (100), 105 (22), 99
(19), 91 (19).
HRMS (EI): m/z [M+] calcd for C16H24O2: 248.1776; found:
248.1773.
IR (neat): 2954, 2930, 2875, 1946 (=•=), 1443, 1272, 1218, 1123,
1108, 1074, 1035, 945, 906, 758, 682 cm–1.
1H NMR (300 MHz, CDCl3): δ = 0.88 (br t, J = 7.0 Hz, 3 H), 1.24–
1.36 (m, 4 H), 1.36–1.48 (m, 2 H), 1.67–1.73 (m, 7 H), 1.96 (dt, J =
2.7, 6.7 Hz, 2 H), 2.29 (br t, J = 6.7 Hz, 2 H), 2.38 (br t, J = 6.7 Hz,
2 H), 3.97 (s, 4 H), 5.60 (br d, J = 10.8 Hz, 1 H), 5.91 (d of sext, J =
2.7, 10.8 Hz, 1 H).
MS (EI): m/z (%) = 276 (M+, 13), 220 (33), 190 (18), 158 (16), 133
(15), 119 (100), 105 (23), 99 (24), 91 (27).
8-(4-Phenethyl-6-phenylhexa-2,3-dien-1-ylidene)-1,4-dioxaspi-
ro[4.5]decane (4k)
Yield: 32.1 mg (80%); colorless oil.
Synthesis 2012, 44, 3623–3632
© Georg Thieme Verlag Stuttgart · New York

PAPER
Coupling of Magnesium Alkylidene Carbenoids with α-Sulfonylallyllithiums
3631
HRMS (EI): m/z [M+] calcd for C18H28O2: 276.2089; found:
276.2091.
HRMS (EI): m/z [M+] calcd for C16H22O2: 246.1620; found:
246.1620.
8-(3-Methylbuta-1,3-dien-1-ylidene)-1,4-dioxaspiro[4.5]decane
(4f); Typical Procedure
8-(2,3-Dimethylbuta-1,3-dien-1-ylidene)-1,4-dioxaspi-
ro[4.5]decane (4s)
Ethyl p-tolyl sulfone was used as the starting material instead of
methyl p-tolyl sulfone for the synthesis of vinyl sulfone 2e required
for the preparation of 4s.
A 1.59 M soln of BuLi in hexane (0.190 mL, 0.302 mmol) was add-
ed dropwise to a soln of 2a (63.1 mg, 0.300 mmol) in THF (1.0 mL)
at –78 °C, and the mixture was allowed to warm to –55 °C over a
period of 20 min. A soln of 3a (32.7 mg, 0.100 mmol) in THF (0.5
mL) and a 1.02 M soln of t-BuMgCl in THF (0.098 mL, 0.100
mmol) were added to the resulting soln at –78 °C. A 2.0 M soln of
i-PrMgCl in THF (0.14 mL, 0.28 mmol) was added to the resulting
soln at –78 °C, and the reaction mixture was allowed to warm to
0 °C over a period of 1.5 h. The reaction was quenched with sat. aq
NH4Cl (1.5 mL) and the mixture was extracted with CHCl3 (3 × 5
mL). The combined organic layers were dried (MgSO4) and con-
centrated under reduced pressure. The residue was purified by col-
umn chromatography on silica gel [Rf = 0.35 (hexane–EtOAc,
10:1)] to give 4f as a colorless oil; yield: 15.3 mg (0.0742 mmol,
74%).
Yield: 18.1 mg (82%); colorless oil.
IR (neat): 2949, 2881, 1951 (=•=), 1619, 1442, 1266, 1200, 1120,
1086, 1034, 943, 926, 896, 878 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.68–1.80 (m, 4 H), 1.82 (s, 3 H),
1.84 (s, 3 H), 2.29 (t, J = 6.4 Hz, 4 H), 3.97 (s, 4 H), 4.866 (s, 1 H),
4.869 (s, 1 H).
MS (EI): m/z (%) = 220 (M+, 96), 159 (27), 133 (28), 119 (49), 105
(32), 99 (100), 91 (44), 86 (58).
HRMS (EI): m/z [M+] calcd for C14H20O2: 220.1463; found:
220.1466.
For spectral properties, see above.
8-[2-(4-Methoxyphenethyl)-3-methylbuta-1,3-dien-1-ylidene]-
1,4-dioxaspiro[4.5]decane (4t)
3-(p-Methoxyphenyl)propyl p-tolyl sulfone was used as the starting
material instead of methyl p-tolyl sulfone for the synthesis of vinyl
sulfone 2f required for the preparation of 4t.
(Z)-8-(3-Ethylpenta-1,3-dien-1-ylidene)-1,4-dioxaspiro[4.5]dec-
ane (4p)
The geometry of the double bond of vinylallene 4p was determined
by NOESY spectrum.
Yield: 25.4 mg (75%); colorless oil.
Yield: 14.3 mg (64%); colorless oil.
IR (neat): 2948, 2883, 1949 (=•=), 1614, 1513, 1442, 1247, 1178,
1120, 1079, 1035, 902, 824, 756, 734 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.71 (t, J = 6.4 Hz, 4 H), 1.81 (s,
3 H), 2.18–2.25 (m, 4 H), 2.45 (br t, J = 7.7 Hz, 2 H), 2.70 (br t, J =
7.7 Hz, 2 H), 3.78 (s, 3 H), 3.96 (s, 4 H), 4.86–4.89 (m, 1 H), 4.94
(br s, 1 H), 6.82 (d, J = 8.6 Hz, 2 H), 7.10 (d, J = 8.6 Hz, 2 H).
MS (EI): m/z (%) = 340 (M+, 67), 295 (12), 121 (100), 101 (15), 99
(24).
HRMS (EI): m/z [M+] calcd for C22H28O3: 340.2038; found:
340.2034.
IR (neat): 2953, 2880, 1950 (=•=), 1718, 1442, 1273, 1241, 1118,
1075, 1033, 951, 943, 903 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.00 (t, J = 7.4 Hz, 3 H), 1.64–1.85
(m, 7 H), 2.03–2.12 (m, 2 H), 2.30–2.36 (m, 4 H), 3.97 (s, 4 H),
5.28–5.36 (m, 1 H), 6.00–6.04 (m, 1 H).
13C NMR (151 MHz, CDCl3): δ = 13.3 (CH3), 13.8 (CH3), 28.2
(CH2), 28.6 (CH2), 35.4 (CH2), 64.3 (CH2), 64.4 (CH2), 89.1 (CH),
101.9 (C), 108.4 (C), 120.5 (CH), 136.1 (C), 200.4 (C).
MS (EI): m/z (%) = 234 (M+, 24), 189 (26), 120 (34), 119 (37), 105
(36), 99 (100), 91 (53), 87 (51), 77 (26).
HRMS (EI): m/z [M+] calcd for C15H22O2: 234.1620; found:
234.1621.
tert-Butyl 2-(1,4-Dioxaspiro[4.5]decan-8-ylidenemethylene)-3-
methylbut-3-enoate (4u)
Yield: 9.1 mg (30%); colorless oil.
8-[2-(Cyclopent-1-en-1-yl)vinylidene]-1,4-dioxaspiro[4.5]dec-
ane (4q)
IR (neat): 3011, 2954, 2884, 1949 (=•=), 1713 (C=O), 1368, 1247,
1161, 1120, 1082, 1065, 1033, 907, 757 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.48 (s, 9 H), 1.76–1.83 (m, 7 H),
2.36–2.43 (m, 4 H), 3.98 (s, 4 H), 5.06–5.09 (m, 1 H), 5.46–5.48 (m,
1 H).
MS (EI): m/z (%) = 306 (M+, 1), 250 (99), 235 (22), 205 (42), 161
(27), 143 (32), 112 (40), 99 (34), 86 (39), 57 (100).
Yield: 15.8 mg (68%); colorless oil.
IR (neat): 2951, 2885, 1952 (=•=), 1441, 1252, 1113, 1068, 1033,
952, 904, 757, 734 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.69–1.82 (m, 4 H), 1.88 (m, 2 H),
2.27–2.35 (m, 6 H), 2.36–2.45 (m, 2 H), 3.97 (s, 4 H), 5.60 (quint,
J = 2.2, 1 H), 5.93 (br s, 1 H).
MS (EI): m/z (%) = 232 (M+, 7), 99 (37), 86 (60), 85 (66), 84 (94),
83 (100).
HRMS (EI): m/z [M+] calcd for C18H26O4: 306.1831; found:
306.1831.
HRMS (EI): m/z [M+] calcd for C15H20O2: 232.1463; found:
232.1461.
Acknowledgment
This work was supported by a Grant-in-Aid for Scientific Research
No. 22590021 from the Ministry of Education, Culture, Sports, Sci-
ence and Technology, Japan, and a TUS Grant for Research Promo-
tion from Tokyo University of Science, which are gratefully
acknowledged.
8-[2-(Cyclohex-1-en-1-yl)vinylidene]-1,4-dioxaspiro[4.5]dec-
ane (4r)
Yield: 19.5 mg (79%); colorless oil.
IR (neat): 2929, 2882, 1952 (=•=), 1437, 1234, 1114, 1068, 1033,
951, 943, 904, 758, 734 cm–1.
1H NMR (300 MHz, CDCl3): δ = 1.54–1.70 (m, 4 H), 1.70–1.84 (m,
4 H), 1.96–2.04 (m, 2 H), 2.05–2.13 (m, 2 H), 2.30 (dt, J = 1.7, 6.3
Hz, 4 H), 3.97 (s, 4 H), 5.61–5.65 (m, 1 H), 5.72 (br s, 1 H).
Supporting Information for this article is available online at
http://www.thieme-connect.com/ejournals/toc/synthesis.SnoIufproi
m
tgioSrantnugIifoop
r
itmnatr
MS (EI): m/z (%) = 246 (M+, 20), 99 (57), 86 (61), 85 (66), 84 (96),
83 (100).
© Georg Thieme Verlag Stuttgart · New York
Synthesis 2012, 44, 3623–3632

3632
T. Kimura et al.
PAPER
3806. (g) Mori, N.; Obuchi, K.; Katae, T.; Sakurada, J.;
Satoh, T. Tetrahedron 2009, 65, 3509. (h) Satoh, T.; Kaneta,
H.; Matsushima, A.; Yajima, M. Tetrahedron Lett. 2009, 50,
6280.
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Synthesis 2012, 44, 3623–3632
© Georg Thieme Verlag Stuttgart · New York