Reaction of 1-chlorovinyl p-tolyl sulfoxides with carbanion of acetonitrile: A novel synthesis of cyclopentanone derivatives with three consecutive carbon-carbon bond-formations via the enaminonitriles

Article abstract of DOI:10.1016/S0040-4020(00)00187-3

Treatment of 1-chlorovinyl p-tolyl sulfoxides derived from ketones with cyanomethyllithium gave cyclopentadienyl enaminonitriles in high yields with three consecutive carbon- carbon bond-formations. However, the 1-chlorovinyl p-tolyl sulfoxides derived from aldehydes did not give good results. The mechanism of this reaction and the reaction of the enaminonitriles to convert cyclopentanone derivatives were investigated. Several α-carbanion of nitriles other than acetonitrile added to the 1-chlorovinyl p-tolyl sulfoxides at low temperature in good yield; however, they did not cyclize upon warming to room temperature. (C) 2000 Elsevier Science Ltd.

Full text of DOI:10.1016/S0040-4020(00)00187-3

TETRAHEDRON
Pergamon
Tetrahedron 56 (2000) 5113±5122
Reaction of 1-Chlorovinyl p-Tolyl Sulfoxides with Carbanion of
Acetonitrile: A Novel Synthesis of Cyclopentanone Derivatives
with Three Consecutive Carbon±Carbon Bond-Formations
via the Enaminonitriles
*
Tsuyoshi Satoh and Hiroyuki Ota
Department of Chemistry, Faculty of Science, Science University of Tokyo, Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan
Received 14 January 2000; accepted 28 February 2000
AbstractÐTreatment of 1-chlorovinyl p-tolyl sulfoxides derived from ketones with cyanomethyllithium gave cyclopentadienyl enamino-
nitriles in high yields with three consecutive carbon±carbon bond-formations. However, the 1-chlorovinyl p-tolyl sulfoxides derived from
aldehydes did not give good results. The mechanism of this reaction and the reaction of the enaminonitriles to convert cyclopentanone
derivatives were investigated. Several a-carbanion of nitriles other than acetonitrile added to the 1-chlorovinyl p-tolyl sulfoxides at low
temperature in good yield; however, they did not cyclize upon warming to room temperature. q 2000 Elsevier Science Ltd. All rights
reserved.
Cyclopentanones are obviously one of the most widely
distributed carbon skeletal structures in natural and
unnatural organic compounds. Because cyclization leading
to the ®ve-membered ring is much easier than that of other
ring sizes, numerous methods for the synthesis of cyclo-
pentane derivatives have been published.1 However, in
view of the importance of cyclopentanone derivatives,
new methods for their synthesis are still eagerly sought.
On the other hand, the formation of several carbon±carbon
bonds in a one-¯ask multistep reaction, sometimes called a
tandem or cascade reaction, is of high value in the construc-
tion of complex organic molecules and the methodology has
received much attention these days.2
compounds 1 and chloromethyl p-tolyl sulfoxide 2, in
organic synthesis.3 In continuation of our studies on
developing new synthetic methods by using 1-chloroalkyl
p-tolyl sulfoxides, herein we report in detail the reaction of
1-chlorovinyl p-tolyl sulfoxides 3 with the a-carbanion of
acetonitrile and related compounds. Especially, the reaction
of 3 with the cyanomethyllithium gave the enaminonitrile 4
in high yields. We also report in detail the transformation of
4 to various kinds of cyclopentanone derivatives such as 54
(Scheme 1).
Results and Discussion
Recently, we have been investigating the use of 1-chloro-
vinyl p-tolyl sulfoxides 3, derived from carbonyl
1-Chlorovinyl p-tolyl sulfoxide 6, which was synthesized
from benzophenone and chloromethyl p-tolyl sulfoxide in
Scheme 1.
Keywords: 1-chlorovinyl p-tolyl sulfoxides; acetonitrile; enaminonitriles.
* Corresponding author. Tel.: 181-3-3260-4271; fax: 181-3-3235-2214; e-mail: tsatoh@ch.kagu.sut.ac.jp
0040±4020/00/$ - see front matter q 2000 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020(00)00187-3

5114
T. Satoh, H. Ota / Tetrahedron 56 (2000) 5113±5122
The proposed mechanism was supported by the experiments
shown in Scheme 4. The reaction of 6 with the cyano-
methyllithium at 2788C for 2 min was quenched with
water to afford the adduct 11 in 90% yield with a trace of
the enaminonitrile 7. When the quench was carried out
with deuterio methanol, deuterated adduct 12 with 96%
deuterium content was obtained. These results show that
one of the intermediates of the reaction should be the
a-sul®nyl carbanion 8 (Scheme 3). Furthermore, the adduct
11 was treated with 3-equivalents of LDA at 2788C for
10 min, then the cyanomethyllithium was added and the
reaction temperature was allowed to warm to room tempera-
ture to give the enaminonitrile 7 in good yield. These results
support the validity of the proposed mechanism shown in
Scheme 3.
Scheme 2.
The results for the reaction of several a-chlorovinyl p-tolyl
sulfoxides with the cyanomethyllithium are summarized in
Figure 1. Stereoview of the enaminonitrile 7.
Scheme 3. The proposed mechanism for the generation of the enaminonitrile 7 from 1-chlorovinyl p-tolyl sulfoxide 6 and cyanomethyllithium.
good yield,3c was treated with 5-equivalents of the cyano-
methyllithium (prepared from acetonitrile and n-BuLi in
THF at 2788C) at 2788C to room temperature for 2 h.
The reaction gave a clean reaction mixture, from which a
crystalline product 7 was obtained in 92% yield (Scheme 2).
Table 1. Entries 1±5 show that, when both R and R0 in the
1-chlorovinyl p-tolyl sulfoxides are an alkyl or an aryl
group, the reaction gives high yields of the products. Entries
2 and 3 show that spiro-type enaminonitriles are obtained
without any problem. We propose that this reaction offers a
good method for the synthesis of spiro-cyclic compounds9
having a cyclopentane moiety. Entries 4 and 5 indicate that
The IR spectra of the product 7 showed NH absorption at
3468 and 3324 cm21. The absorption at 2188 cm21 was
considered to be a nitrile; however, the value was
abnormally low compared to that of the usual nitriles
(2285±2200 cm21).5 From other spectral data and X-ray
crystallographic analysis (see Fig. 1),6 the structure of the
product was established as an enaminonitrile 7.
The mechanism of this interesting reaction was considered
to be as follows (Scheme 3). Michael-type addition of
the cyanomethyllithium to the double bond of 6 gave the
a-sul®nyl carbanion having a chlorine atom 8. Elimination
of lithium chloride from 8 afforded an a-sul®nyl carbene (or
carbenoid),7 which was attacked by a second cyanomethyl-
lithium to give an a-sul®nyl carbanion of dinitrile
compound 10. The Thorpe±Ziegler reaction8 of the dinitrile
10 with the elimination of the sul®nyl group took place to
give the enaminonitrile 7 in high yield.
Scheme 4. Supporting experiments for the mechanism shown in Scheme 3.

T. Satoh, H. Ota / Tetrahedron 56 (2000) 5113±5122
5115
Table 1. Reaction of 1-chlorovinyl p-tolyl sulfoxides with LiCH2CN
both geometrical isomers react similarly with the cyano-
methyllithium.
31. These products would produce several compounds
under the basic conditions to give a complex mixture at
elevated temperature.
In contrast to the good results described above, the
a-chlorovinyl sulfoxides having a hydrogen on their
b-position showed very different results. Entries 6 and 7
show that the a-chlorovinyl sulfoxides derived from
benzaldehyde gave only a tarry complex mixture. The
1-chlorovinyl sulfoxides derived from 3-phenylpropanal
gave the desired product; however, the reaction mixture
was rather complex and the yield of the enaminonitrile
was low (entries 8 and 9).
Reaction of the 1-chlorovinyl p-tolyl sulfoxides with
other carbanions of alkylcyanides
We also investigated the reaction of the 1-chlorovinyl
p-tolyl sulfoxides with the cyanomethylmagnesium
bromide, which was generated from the cyanomethyl-
lithium with magnesium bromide etherate, and the results
are summarized in Table 2.
To elucidate the reason why the reaction with the 1-chloro-
vinyl sulfoxides derived from aldehydes gave a complex
mixture, we investigated an experiment shown in Scheme 5.
Similarly to the cyanomethyllithium, the cyanomethyl-
magnesium bromide added to the 1-chlorovinyl p-tolyl
sulfoxides in moderate to good yields. However, in contrast
to the cyanomethyllithium the reaction did not give the
enaminonitrile upon warming to room temperature. This
implies that the intermediate magnesium carbenoide is
stable and also has low reactivity toward the cyanomethyl-
magnesium bromide. As shown in entries 2 and 3, even the
1-chlorovinyl p-tolyl sulfoxides derived from aldehydes
Thus, 1-chlorovinyl p-tolyl sulfoxide 18 was treated with
the cyanomethyllithium at 2788C for 10 min, then
quenched with water to afford the adduct 27 together with
the rearranged products 28 and 29. The rearranged products
28 and 29 were thought to be produced from the adduct 30
through the rearrangement of the hydrogen in the carbenoid

5116
T. Satoh, H. Ota / Tetrahedron 56 (2000) 5113±5122
Table 2. Reaction of 1-chlorovinyl p-tolyl sulfoxides with BrMgCH2CN
Scheme 5.
gave the adduct without rearrangement products (compare
to the results in Scheme 5).
vigorous conditions gave decyanated enone 38 in 75%
yield.
Finally, we investigated the reaction of the 1-chlorovinyl
p-tolyl sulfoxide 6 with the 1-cyanoalkyllithium other than
cyanomethyllithium (Scheme 6). The reaction of 6 with the
1-cyanoethyllithium at 2788C gave the adduct 34 in good
yield. However, upon warming the reaction temperature, the
reaction gave a complex mixture and the expected cyclized
product was not obtained. The dianion of glutaronitrile and
adiponitrile also added to 6 to give the adduct 35 and 36,
respectively, in good yields. Again, elevation of the reaction
temperature gave a complex mixture and the expected
cyclized product could not be obtained.
Catalytic hydrogenation of 7 with Pd±C in methanol gave
enaminonitrile 39 in quantitative yield. The tetra-substituted
double bond could not be reduced under these conditions.
Catalytic hydrogenation of 7 with PtO2 in acetic anhydride
gave an acetamide 40 in moderate yield. N-Methylation of 7
Conversion of the enaminonitriles to several
cyclopentanone derivatives
In order to convert the enaminonitriles to compounds useful
in organic synthesis, we tried some reactions to 7 and 23
(Scheme 7). Acidic hydrolysis of the enaminonitrile 7 with
diluted hydrochloric acid in re¯uxing tert-BuOH10 gave the
enone 37 in high yield. The acidic hydrolysis under more
Scheme 6.

T. Satoh, H. Ota / Tetrahedron 56 (2000) 5113±5122
5117
Scheme 7.
was successful with iodomethane and sodium hydride to
give N,N-dimethyl product 41 in good yield. The cyano
group of 7 is so stable that it was not reacted with
DIBAL, LiAlH4, and EtMgBr.
Experimental
Mps were measured with a Yanagimoto micro melting point
apparatus and are uncorrected. 1H NMR spectra were
measured in a CDCl3 solution with JEOL JNM-LA 400
and 500 spectrometers. Electron-impact mass spectra
(MS) were obtained at 70 eV by direct insertion. Silica gel
60 (Merck) containing 0.5% ¯uorescence reagent 254 and a
quartz column were used for column chromatography and
the products having UV absorption were detected by UV
irradiation. In experiments requiring a dry solvent, THF was
distilled from sodium diphenylketyl; DMSO, DMF, and
acetonitrile were distilled from CaH2.
Catalytic hydrogenation of the enone 37 gave ketone 42 in
quantitative yield. Again, we could not reduce the cyano
group of 42. Alkylation of 37 with iodomethane in the
presence of sodium hydride gave a mixture of C-methylated
product 44 and O-methylated product 45. The reaction of 37
with iodopentane gave only O-pentyl product 46 in quanti-
tative yield. Attempts to protect the carbonyl group of 37
with dimethyl acetal with methyl orthoformate gave only an
enolether 45. Treatment of 46 with LiAlH4 gave cyano-
ole®ne 47 in moderate yield and no reduction of the cyano
group was effected.
2-Amino-1-cyano-5,5-diphenyl-1,3-cyclopentadiene (7).
Acetonitrile (0.094 ml; 1.8 mmol) was added to a solution
of n-BuLi (1.5 mmol) in 3 ml of dry THF at 2788C with
stirring. The solution was stirred for 10 min, then a solution
of 63c (111.3 mg; 0.3 mmol) in THF (1 ml) was added. The
temperature of the reaction mixture was gradually allowed
to warm to room temperature for 2 h. The reaction was
quenched by sat. aq. NH4Cl. The whole was extracted
with AcOEt. The organic layer was washed once with sat.
aq. NH4Cl. The product was isolated by silica gel column
chromatography to give 71 mg (92%) of 7 as colorless
Spiro-type enaminonitrile 23 was heated in aqueous phos-
phoric acid to give quite interesting spiro enediones 48 and
49 in quantitative yield in total.
We are continuing work on the reaction of the 1-chlorovinyl
p-tolyl sulfoxides with several carbanions, and the extension
of the presented reaction to asymmetric synthesis. The
results will be reported in due course.

5118
T. Satoh, H. Ota / Tetrahedron 56 (2000) 5113±5122
crystals. Mp 170±1728C (AcOEt±hexane); IR (KBr) 3468
H, 5.93; Cl, 12.28; S, 11.10. Found: C, 53.97; H, 5.81; Cl,
12.19; S, 11.18.
1
(NH), 3324 (NH), 2188 (CN), 1655, 762, 700 cm21; H
NMR d 4.75 (2H, br s), 6.17, 6.95 (each 1H, d,
Jˆ5.6 Hz), 7.2±7.4 (10H, m). 13C NMR d 67.8, 86.7,
118.4, 125.6, 127.2, 127.4, 128.6, 141.4, 152.0, 159.7. MS
m/z (%) 258 (M1, 100), 181 (27), 28 (36). Anal. Calcd for
C18H14N2: C, 83.69; H, 5.46; N, 10.84. Found: C, 83.75; H,
5.31; N, 10.72.
The acetate (152 mg; 0.53 mmol) was dissolved in 2 ml of
DMSO. To this was added NaH (42 mg; 1.05 mmol) and the
suspension was stirred for 3 h. The solution was diluted with
ether (10 ml) and cooled in an ice bath. The reaction was
quenched by adding a solution of acetic acid (1 ml) in 10 ml
of ether. The whole was extracted with ether±benzene,
washed once with half-saturated aq. NH4Cl. The product
was isolated by ¯ash chromatography using silica gel to
give 64 mg (53%) of 13 and starting acetate (47%). 13:
colorless crystals; mp 103±1048C (AcOEt±hexane). IR
4-Chloro-3,3-diphenyl-4-(p-tolylsul®nyl)butyronitrile (11).
Acetonitrile (0.047 ml; 0.9 mmol) was added to a solution
of n-BuLi (0.75 mmol) in 2 ml of dry THF at 2788C with
stirring. The solution was stirred for 10 min, then a solution
of 6 (53.0 mg; 0.15 mmol) in THF (1 ml) was added. The
solution was stirred for 2 min, then the reaction was
quenched by adding sat. aq. NH4Cl. The whole was
extracted with AcOEt. The product was puri®ed by silica
gel column chromatography to afford 11 (53.2 mg; 90%) as
colorless crystals; mp 189±1928C (AcOEt±hexane); IR
1
(KBr) 1084, 1058 cm21; H NMR d 2.01 (3H, s), 2.33
(3H, s), 2.41 (3H, s), 7.31, 7.48 (each 2H, d, Jˆ8 Hz). MS
m/z (%) 228 (M1, 78), 211 (87), 53 (100). Anal. Calcd for
C11H13ClOS: C, 57.76; H, 5.73; Cl, 15.50; S, 14.02. Found:
C, 57.71; H, 5.65; Cl, 15.36; S, 14.14.
1
(KBr) 2245 (CN), 1050 (SO), 705 cm21; H NMR d 2.44
The 1-chlorovinyl p-tolyl sulfoxides 14±17 are known
(3H, s), 3.54, 4.35 (each 1H, d, Jˆ16.3 Hz), 5.31 (1H, s),
7.2±7.8 (14H, m). MS m/z (%) 393 (M1, trace), 254 (61),
178 (58), 140 (100). Anal. Calcd for C23H20ClNOS: C,
70.13; H, 5.12; N, 3.56; Cl, 9.00; S, 8.14. Found: C,
70.03; H, 5.10; N, 3.41; Cl, 9.15; S, 8.20.
compounds.3c
(Z)-1-Chloro-2-phenyl-1-(p-tolylsul®nyl)ethene (18) and
(E)-isomer (19). These compounds were synthesized from
chloromethyl p-tolyl sulfoxide 2 and benzaldehyde in a
similar way as described for 13. Chloro alcohol: yellow
viscous oil. IR (KBr) 3356 (OH), 1043 (SO) cm21. To a
solution of the chloro alcohol (1.13 g; 3.83 mmol) in dry
CH2Cl2 was added triethylamine (0.7 ml) followed by
methanesulfonyl chloride (0.39 ml; 5 mmol) with stirring
at 08C. The reaction mixture was stirred at 08C for
30 min, then at room temperature for 4 h. The reaction
was quenched with water, and the whole was extracted
with CH2Cl2. The organic layer was washed successively
with 10% HCl, sat. NaHCO3, then sat. brine. The usual
workup followed by silica gel column chromatography
gave 18 (0.44 g; 42%) and 19 (0.53 g; 50%). 18: Colorless
crystals; mp 136±1388C (AcOEt±hexane); IR (KBr) 1084,
4-Chloro-4-deuterio-3,3-diphenyl-4-(p-tolylsul®nyl)-
butyronitrile (12). Colorless crystals; IR (KBr) 2241 (CN),
1053 (SO), 699 cm21; 1H NMR: the signal of the hydrogen
on the carbon bearing the chlorine atom (d 5.31) almost
disappeared.
1-Chloro-2-methyl-1-(p-tolylsul®nyl)-1-propene (13). A
solution of 2 (755 mg; 4 mmol) in dry THF (4 ml) was
added dropwise to a solution of LDA (5 mmol) in 15 ml
of THF at 2788C. The solution was stirred at 2788C for
10 min, then acetone (0.23 ml; 5 mmol) was added. The
reaction mixture was stirred for 10 min and the reaction
was quenched by sat. aq. NH4Cl. The whole was extracted
with AcOEt. The organic layer was washed once with sat.
aq. NH4Cl and dried over MgSO4. The solvent was evapo-
rated to leave colorless crystals. The crystals were washed
with a mixture of hexane±AcOEt (10:1) to give pure chloro
alcohol. Recrystallization of the crystals from AcOEt±
hexane gave colorless crystals (699 mg; 71%); mp 136±
1388C (AcOEt±hexane); IR (KBr) 3389 (OH), 1044 (SO)
cm21; 1H NMR d 1.60 (6H, s), 2.43 (3H, s), 2.71 (1H, br s),
4.27 (1H, s), 7.35, 7.49 (each 2H, d, Jˆ8.3 Hz). MS m/z (%)
246 (M1, 4), 140 (100), 92 (56). Calcd for C11H15ClO2S: M,
246.0481. Found: m/z 246.0491.
1
1052 cm21; H NMR d 2.42 (3H, s), 7.31±7.54 (10H, m).
MS m/z (%) 276 (M1, 7), 228 (100), 140 (61). Anal. Calcd
for C15H13ClOS: C, 65.09; H, 4.73; Cl, 12.81; S, 11.59.
Found: C, 64.98; H, 4.62; Cl, 12.92; S, 11.78. 19: Colorless
crystals; mp 59±618C (AcOEt±hexane); IR (KBr) 1082,
1
1065 cm21; H NMR d 2.42 (3H, s), 7.31±7.77 (10H, m).
MS m/z (%) 276 (M1, 10), 228 (100). Anal. Calcd for
C15H13ClOS: C, 65.09; H, 4.73; Cl, 12.81; S, 11.59.
Found: C, 64.77; H, 4.61; Cl, 12.82; S, 11.70.
(Z)-1-Chloro-4-phenyl-1-(p-tolylsul®nyl)-1-butene (20)
and (E)-isomer (21). These compounds were synthesized
from chloromethyl p-tolyl sulfoxide 2 and 3-phenylpropanal
in a similar way as described for 13. Chloro alcohol: color-
4-Dimethylaminopyridine (65.4 mg; 0.54 mmol) was added
to a suspension of the chloro alcohol (661 mg; 2.68 mmol)
in a mixture of acetic anhydride (5 ml) and pyridine (5 ml).
The suspension was stirred at room temperature for 13 h.
The acetic anhydride and pyridine were evaporated under
vacuum and the residue was puri®ed by silica gel column
chromatography to give acetate (774 mg; quantitive yield)
as colorless crystals; mp 68±708C (AcOEt±hexane). IR
1
less crystals. IR (KBr) 3364 (OH), 1032 (SO) cm21; H
NMR d 1.89±2.12 (2H, m), 2.44 (3H, s), 2.68±2.92 (2H,
m), 3.9±4.5 (3H, m), 7.1±7.5 (9H, m).
To a solution of the chloro alcohol (1.71 g; 5.3 mmol) in dry
CH2Cl2 was added triethylamine (1.5 ml) followed by
methanesulfonyl chloride (0.82 ml; 10.6 mmol) with stir-
ring at 08C. The reaction mixture was stirred at 08C for
30 min, then 1,8-diazabicyclo[5.4.0]undec-7-ene (3.0 ml;
20 mmol) was added to the reaction mixture at room
temperature. The reaction mixture was stirred for 10 min
1
(KBr) 1727 (CO), 1241 cm21; H NMR d 1.67, 1.78 (each
3H, s), 2.12 (3H, s), 2.42 (3H, s), 5.30 (1H, s), 7.33, 7.47
(each 2H, d, Jˆ8 Hz). MS m/z (%) 289 ([M1H]1, trace),
149 (36), 43 (100). Anal. Calcd for C13H17ClO3S: C, 54.07;

T. Satoh, H. Ota / Tetrahedron 56 (2000) 5113±5122
5119
at room temperature. The reaction was quenched with water,
and the whole was extracted with CH2Cl2. The organic layer
was washed successively with 10% HCl, sat. NaHCO3, then
sat. brine. The usual workup followed by silica gel column
chromatography gave 20 (0.63 g; 39%) and 21 (0.85 g;
53%). 20: Colorless crystals; mp 87±898C (AcOEt±
4-Chloro-3-phenyl-4-( p-tolylsul®nyl)butyronitrile (27).
Colorless crystals; mp 184±1868C (AcOEt±hexane). IR
1
(KBr) 2250 (CN), 1087, 1050, 698, 514 cm21; H NMR d
2.43 (3H, s), 2.95 (1H, dd, Jˆ3.7, 17.1 Hz), 3.05 (1H, dd,
Jˆ8.3, 17.1 Hz), 3.73±3.79 (1H, m), 4.69 (1H, d,
Jˆ9.8 Hz), 7.2±7.5 (9H, m). MS m/z (%) 317 (M1, 14),
178 (70), 140 (100). Anal. Calcd for C17H16ClNOS: C,
64.24; H, 5.07; N, 4.41; Cl, 11.15; S, 10.09. Found: C,
63.87; H, 4.93; N, 4.33; Cl, 11.20; S, 10.17.
1
hexane); IR (KBr) 1083, 1057 cm21; H NMR d 2.41 (3H,
s), 2.57±2.84 (4H, m), 6.76 (1H, t, Jˆ7.2 Hz), 7.2±7.5 (9H,
m). MS m/z (%) 304 (M1, 1), 287 (100), 91 (90). Anal.
Calcd for C17H17ClOS: C, 66.98; H, 5.62; Cl, 11.63; S,
10.52. Found: C, 66.92; H, 5.56; Cl, 11.71; S, 10.68. 21:
Colorless crystals; mp 56±588C (AcOEt±hexane); IR (KBr)
1086, 1058 cm21; 1H NMR d 2.40 (3H, s), 2.77±3.08 (4H,
m), 6.32 (1H, t, Jˆ7.8 Hz), 7.2±7.5 (9H, m). MS m/z (%)
304 (M1, 20), 197 (59), 91 (100). Anal. Calcd for
C17H17ClOS: C, 66.98; H, 5.62; Cl, 11.63; S, 10.52.
Found: C, 66.78; H, 5.54; Cl, 11.88; S, 10.71.
(E)-3-Cyano-2-phenyl-1-( p-tolylsul®nyl)-1-propene (28)
and (Z)-isomer (29). 28: This compound was decided by
1H NMR spectra; d 4.22, 4.37 (each 1H, d, Jˆ13 Hz), 5.73
(1H, s, vinyl-H). 29: Colorless oil; IR (neat) 2216 (CN),
1086, 1048 cm21 1H NMR d 2.40 (3H, s), 3.88, 3.99
;
(each 1H, d, Jˆ13 Hz), 5.39 (1H, s), 7.26±7.43 (9H, m).
MS m/z (%) 281 (M1, 6), 139 (100). Calcd for C17H15NOS:
M, 281.0873. Found: m/z 281.0877.
2-Amino-1-cyano-5,5-dimethyl-1,3-cyclopentadiene (22).
Colorless crystals; mp 93±948C (AcOEt±hexane); IR (KBr)
3432 (NH), 3341 (NH), 2166 (CN), 1649 cm21; 1H NMR d
1.27 (6H, s), 4.46 (2H, br s), 5.97, 6.46 (each 1H, d,
Jˆ5.5 Hz). MS m/z (%) 134 (M1, 45), 119 (100), 92 (21).
Anal. Calcd for C8H10N2: C, 71.61; H, 7.51; N, 20.88.
Found: C, 71.29; H, 7.47; N, 20.64.
1-[Chloro-( p-tolylsul®nyl)methyl]-1-cyanomethyl-4,4-
ethylenedioxycyclohexane (32). Acetonitrile (0.063 ml;
1.2 mmol) was added to a solution of n-BuLi (1.0 mmol)
in 2 ml of dry THF at 2788C with stirring. The solution was
stirred for 10 min, then a solution of magnesiumbromide
etherate (310 mg; 1.2 mmol) in THF (10 ml) was added.
The reaction mixture was stirred for 10 min at 2788C,
then a solution of 14 (65.4 mg; 0.2 mmol) in THF (1 ml)
was added. The temperature of reaction mixture was gradu-
ally allowed to warm to room temperature for 2 h. The
reaction was quenched by sat. aq. NH4Cl. The whole was
extracted with AcOEt. The organic layer was washed once
with sat. aq. NH4Cl. The product was isolated by silica gel
column chromatography to give 59 mg of 32 as colorless
crystals. Less polar 32: colorless crystals; mp 112±1148C
(AcOEt±hexane); IR (KBr) 2241 (CN), 1104, 1080,
2-Amino-1-cyano-8,8-ethylenedioxyspiro[4.5]daca-1,3-
diene (23). Colorless crystals; mp 249±2518C (AcOEt±
hexane); IR (KBr) 3418 (NH), 3347 (NH), 2162 (CN),
;
1660, 1613 cm21 1H NMR d 1.49±1.53, 1.71±1.78,
1.92±1.96, 2.03±2.10 (each 2H, m), 3.96±4.00 (4H, m),
4.53 (2H, br s), 6.08, 6.83 (each 1H, d, Jˆ5.6 Hz). 13C
NMR d 30.8, 33.4, 55.6, 64.4, 87.1, 108.0, 118.1, 126.1,
149.8, 158.2. MS m/z (%) 232 (M1, 43), 204 (57), 118
(100). Anal. Calcd for C13H16N2O2: C, 67.22; H, 6.94; N,
12.06. Found: C, 66.87; H, 6.84; N, 11.87.
1
1052 cm21; H NMR d 1.6±1.8 (4H, m), 1.8±1.9 (1H, m),
2.0±2.1 (1H, m), 2.2±2.3 (1H, m), 2.4 (1H, m), 2.44 (3H, s),
2.90, 3.45 (each 1H, d, Jˆ17.1 Hz), 3.96 (4H, s), 4.69 (1H,
s), 7.34, 7.76 (each 2H, d, Jˆ8.3 Hz). MS m/z (%) 367 (M1,
2), 228 (100). Anal. Calcd for C18H22ClNO3S: C, 58.77; H,
6.03; N, 3.81; Cl, 9.62; S, 8.72. Found: C, 58.52; H, 5.81; N,
3.72; Cl, 9.60; S, 8.71. More polar 32: colorless crystals; mp
167±1698C (AcOEt±hexane); IR (KBr) 2240 (CN), 1110,
1084, 1051 cm21; 1H NMR d 1.67±1.76 (4H, m), 1.97±2.05
(1H, m), 2.08±2.20 (2H, m), 2.28±2.40 (1H, m), 2.44 (3H,
s), 2.90, 2.99 (each 1H, d, Jˆ17.3 Hz), 3.97 (4H, s), 4.48
(1H, s), 7.36, 7.48 (each 2H, d, Jˆ8.0 Hz). MS m/z (%) 367
(M1, 13), 228 (100), 192 (85). Calcd for C18H22ClNO3S: M,
367.1009. Found: m/z 367.1013.
2-Amino-1-cyanospiro[4.14]nonadeca-1,3-diene (24). Color-
less crystals; mp 152±1548C (AcOEt±hexane); IR (KBr)
1
3450 (NH), 3348 (NH), 2169 (CN), 1642 cm21; H NMR
d 1.3±1.7 (28H, m), 4.48 (2H, br s), 5.99, 6.55 (each 1H, d,
Jˆ5.6 Hz). MS m/z (%) 300 (M1, 100), 119 (85), 118 (67).
Anal. Calcd for C20H32N2: C, 79.94; H, 10.73; N, 9.32.
Found: C, 79.53; H, 10.68; N, 9.20.
2-Amino-1-cyano-5-methyl-5-phenyl-1,3-cyclopentadiene
(25). Colorless crystals; mp 161±1648C (AcOEt±hexane);
IR (KBr) 3433 (NH), 3346 (NH), 2167 (CN),
1
1649 cm21; H NMR d 1.68 (3H, s), 4.69 (2H, br s),
6.07, 6.67 (each 1H, d, Jˆ5.5 Hz), 7.2±7.3 (5H, m). 13C
NMR d 22.2, 59.0, 88.0, 118.1, 125.1, 125.8, 126.9,
128.6, 140.4, 153.6, 158.9. MS m/z (%) 196 (M1, 100),
181 (89), 154 (12). Calcd for C13H12N2: M, 196.1000.
Found: m/z 196.1004.
3-[Chloro-( p-tolylsul®nyl)methyl]-5-phenylvaleronitrile
(33). Less polar 33: colorless oil; IR (neat) 2240 (CN), 1084,
1050, 700 cm21; 1H NMR d 2.0±2.2 (3H, m), 2.45 (3H, s),
2.6±2.7 (2H, m), 2.8±3.0 (2H, m), 4.43 (1H, d, Jˆ1.9 Hz),
7.1±7.7 (9H, m). MS m/z (%) 345 (M1, trace), 292 (25), 140
(81), 91 (100). Calcd for C19H20ClNOS: M, 345.0955.
Found m/z 345.0955. More polar 33: colorless oil; IR
2-Amino-1-cyano-5-(2-phenylethyl)-1,3-cyclopentadiene
(26). Colorless crystals; mp 95±988C (AcOEt±hexane); IR
1
1
(KBr) 3411 (NH), 3344 (NH), 2172 (CN), 1647 cm21; H
(neat) 2242 (CN), 1495, 1455, 1089, 1058, 701 cm21; H
NMR d 1.82±1.89 (1H, m), 2.04±2.11 (1H, m), 2.66±2.78
(2H, m), 3.43 (1H, dd, Jˆ7.3, 6.1 Hz), 4.59 (2H, br s), 6.16,
6.56 (each 1H, d, Jˆ5.5 Hz), 7.1±7.4 (5H, m). MS m/z (%)
210 (M1, 54), 119 (82), 91 (100). Calcd for C14H14N2: M,
210.1155. Found: m/z 210.1153.
NMR d 1.9±2.0 (1H, m), 2.3±2.4 (1H, m), 2.42 (3H, s),
2.43±2.54 (1H, m), 2.5±2.8 (4H, m), 4.54 (1H, d,
Jˆ4.6 Hz), 7.1±7.5 (9H, m). MS m/z (%) 345 (M1, 1),
140 (83), 91 (100). Calcd for C19H20ClNOS: M, 345.0954.
Found m/z 345.0948.

5120
T. Satoh, H. Ota / Tetrahedron 56 (2000) 5113±5122
4-Chloro-2-methyl-3,3-diphenyl-4-(p-tolylsul®nyl)butyro-
nitrile (34). Propionitrile (0.05 ml; 0.7 mmol) was added to
a solution of n-BuLi (0.6 mmol) in 2 ml of dry THF at
2788C with stirring. The solution was stirred for 10 min,
then a solution of 6 (52.9 mg; 0.15 mmol) in THF (1 ml)
was added. The reaction mixture was stirred for 15 min at
2788C. The reaction was quenched by sat. aq. NH4Cl. The
whole was extracted with AcOEt. The organic layer was
washed once with sat. aq. NH4Cl. The product was isolated
by silica gel column chromatography to give 43 mg (71%)
of 34 as colorless crystals; mp 215±2178C (AcOEt±
acid; 75% P2O5) and the reaction mixture was stirred for
25 h at 1508C (bath temperature). The reaction was
quenched by sat. aq. NaHCO3. The whole was extracted
with AcOEt, washed once with sat. aq. NaHCO3. The
product was isolated by silica gel column chromatography
to give 38 (44 mg; 75%) as colorless oil. IR (neat) 1714
1
(CO), 1588, 1492, 1446, 758, 699 cm21; H NMR d 3.13
(2H, s), 6.25, 7.99 (each 1H, d, Jˆ5.8 Hz), 7.1±7.4 (10H,
m). MS m/z (%) 234 (M1, 100), 206 (57), 131 (46). Calcd
for C17H14O: M, 234.1044. Found: m/z 234.1044.
1
hexane). IR (KBr) 2237 (CN), 1083, 1063 (SO) cm21; H
1-Amino-2-cyano-3,3-diphenylcyclopentene (39). To a
solution of 7 (52 mg; 0.2 mmol) in 4 ml of MeOH was
added 10 mg of Pd±C (10%) and the suspension was stirred
under H2 atmosphere at room temperature for 2 h. The Pd±
C was ®ltered off and the solvent was evaporated to give a
residue, which was puri®ed by silica gel column chromato-
graphy to give quantitative yield of 39 (52 mg) as colorless
crystals; mp 179±1818C (AcOEt±hexane). IR (KBr) 3443
(NH), 3354 (NH), 2177 (CN), 1642, 1599 cm21; 1H NMR d
2.56±2.62 (4H, m), 4.64 (2H, b), 7.2±7.4 (10H, m). MS m/z
(%) 260 (M1, 19), 183 (100). Anal. Calcd for C18H16N2: C,
83.04; H, 6.19; N, 10.76. Found: C, 82.98; H, 6.05; N, 10.70.
NMR d 1.13 (3H, d, Jˆ7.0 Hz), 2.43 (3H, s), 5.35 (1H, br s),
5.69 (1H, s), 7.25±7.75 (14H, m). MS m/z (%) 408
([M1H]1, trace), 268 (56), 214 (100), 179 (63). Anal.
Calcd for C24H22ClNOS: C, 70.66; H, 5.44; N, 3.43; Cl.
8.69; S, 7.86. Found: C, 70.50; H, 5.51; N, 3.37; Cl, 8.65;
S, 7.86.
1-Chloro-3,5-dicyano-2,2-diphenyl-1-(p-tolylsul®nyl)-
pentane (35). Glutaronitrile (0.03 ml; 0.32 mmol) was
added to a solution of n-BuLi (0.6 mmol) in 2 ml of dry
THF at 2788C with stirring. The solution was stirred for
10 min, then a solution of 6 (52.9 mg; 0.15 mmol) in THF
(1 ml) was added. The reaction mixture was stirred for
30 min at 2788C. The reaction was quenched by sat. aq.
NH4Cl. The whole was extracted with AcOEt. The organic
layer was washed once with sat. aq. NH4Cl. The product was
isolated by silica gel column chromatography to give 71 mg
(83%) of 35 as colorless crystals; mp 200±2038C (CH2Cl2±
hexane); IR (KBr) 2248 (CN), 1042 (SO) cm21; 1H NMR d
1.20±1.29 (2H, m), 2.43 (3H, s), 2.44±2.58 (2H, m), 5.38
(1H, br d, Jˆ10.8 Hz), 5.64 (1H, s), 7.25±7.74 (14H, m).
MS m/z (%) 447 ([M1H]1, 4), 93 (100). Calcd for
C26H24ClN2OS: M, 447.1298. Found: m/z 447.1292.
1-Acetylamino-2-(acetylamino)methyl-3,3-diphenylcyclo-
pentene (40). To a solution of 7 (41 mg; 0.16 mmol) in a
mixture of acetic anhydride (5 ml) and acetic acid (2 ml)
was added 10 mg of PtO2 and the suspension was stirred
under H2 atmosphere at room temperature for 65 h. The
PtO2 was ®ltered off and the solvent was evaporated under
vacuum to give a residue, which was puri®ed by silica gel
column chromatography to give 53% yield of 40 (29 mg) as
colorless crystals; mp 159±1628C (AcOEt±hexane). IR
(KBr) 3429 (NH), 1692 (CO), 1664 (CO), 1522,
1
1376 cm21; H NMR d 1.64 (3H, s), 2.12 (3H, s), 2.60,
3.05 (2H, t, Jˆ7.2 Hz), 3.70 (2H, d, Jˆ6.6 Hz), 4.52 (1H,
b), 7.1±7.4 (10H, m), 9.77 (1H, b). MS m/z (%) 348 (M1,
25), 289 (100), 230 (72). Calcd for C22H24N2O2: M,
348.1836. Found: m/z 348.1830.
1-Chloro-3,6-dicyano-2,2-diphenyl-1-(p-tolylsul®nyl)-
hexane (36). Colorless crystals; mp 201±2048C (CHCl3±
1
hexane); IR (KBr) 2241 (CN), 1044 (SO), 708 cm21; H
NMR d 1.84±1.96 (3H, m), 2.27±2.43 (3H, s), 2.44 (3H,
s), 5.25 (1H, br d, Jˆ10.7 Hz), 5.67 (1H, s), 7.32±7.75
(14H, m). MS m/z (%) 460 (M, trace), 321 (82), 273
(100), 179 (85). Calcd for C27H25ClN2OS: M, 460.1376.
Found: m/z 460.1363.
1-Cyano-2-dimethylamino-5,5-diphenyl-1,3-cyclopenta-
diene (41). A solution of 7 (139 mg; 0.54 mmol) in DMF
(3 ml) was added NaH (108 mg; 2.7 mmol) and iodo-
methane (0.17 ml; 2.7 mmol). The suspension was stirred
at room temperature for 2 h and the reaction was quenched
by sat. aq. NH4Cl. The whole was extracted with AcOEt and
after the usual workup followed by silica gel column chro-
matography to give 41 (136 mg; 88%) as colorless crystals;
mp 166±1698C (AcOEt±hexane). IR (KBr) 2161 (CN),
5-Cyano-4,4-diphenyl-2-cyclopentenone (37). 4 ml of
15% HCl was added to a solution of 7 (325 mg;
1.25 mmol) in 10 ml of t-BuOH. The reaction mixture was
stirred for 2 h at 808C. The reaction was quenched by sat. aq.
NaHCO3. The whole was extracted with ether±benzene,
washed once with sat. aq. NaHCO3. The product was
isolated by silica gel column chromatography to give 37
(304 mg; 94%) as colorless crystals; mp 121±1248C
(AcOEt±hexane). IR (KBr) 2242 (CN), 1742, 1708 (CO)
1
1622, 1560, 699 cm21; H NMR d 3.20 (6H, s), 6.36 (1H,
d, Jˆ5.8 Hz), 6.89 (1H, d, Jˆ5.8 Hz), 7.2±7.3 (10H, m).
MS m/z (%) 286 (M1, 100), 209 (34). Anal. Calcd for
C20H18N2: C, 83.88; H, 6.34; N, 9.78. Found: C, 83.45; H,
6.24; N, 9.71.
1
cm21; H NMR d 4.12 (1H, s), 6.42, 8.06 (each 1H, d,
Jˆ5.8 Hz), 6.9±7.0 (2H, m), 7.2±7.5 (8H, m). MS m/z
(%) 259 (M1, 100), 230 (30), 105 (23). Anal. Calcd for
C18H13NO: C, 83.37; H, 5.05; N, 5.40. Found: C, 83.02;
H, 4.94; N, 5.31.
2-Cyano-3,3-diphenylcyclopentanone (42). This com-
pound was synthesized from 37 as described for 39. Color-
less crystals; mp 128±1318C (AcOEt±hexane); IR (KBr)
1
2214 (CN), 1647, 1399, 703 cm21; H NMR d 2.50±2.54
(2H, m), 2.70±2.83 (2H, m), 3.87 (1H, s), 7.1±7.4 (10H, m).
MS m/z (%) 261 (M1, 100), 184 (41), 115 (31). Anal. Calcd
for C18H15NO: C, 82.73; H, 5.79; N, 5.36. Found: C, 82.40;
H, 5.77; N, 5.25.
4,4-Diphenyl-2-cyclopentenone (38). To a solution of 7
(65 mg; 0.25 mmol) in a mixture of 1,4-dioxane (2 ml)
and water (2 ml) was added 3 ml of PPA (polyphosphoric

T. Satoh, H. Ota / Tetrahedron 56 (2000) 5113±5122
5121
2-(Acetylamino)methyl-3,3-diphenylcyclopentanone (43).
This compound was synthesized from 37 as described for
40. Colorless crystals; mp 148±1528C (AcOEt±hexane); IR
Jˆ5.6 Hz). MS m/z (%) 164 (M1, 100), 94 (38), 55 (82).
Anal. Calcd for C10H12O2: C, 73.15; H, 7.37. Found: C,
72.95; H, 7.49. 49: Colorless oil; IR (neat) 2244 (CN),
1
1
(KBr) 3317 (NH), 1736 (CO), 1636 (CO), 701 cm21; H
1714 (CO), 1591, 1170 cm21; H NMR d 2.05±2.14 (3H,
NMR d 1.96 (3H, s), 2.35±2.58 (4H, m), 2.94±3.01 (1H,
m), 3.28 (1H, dd, Jˆ10.6, 4.0 Hz), 3.71±3.77 (1H, m), 6.22
(1H, b), 7.0±7.4 (10H, m). MS m/z (%) 307 (M1, 22), 235
(88), 230 (75), 159 (100). Anal. Calcd for C20H21NO2: C,
78.15; H, 6.89; N, 4.56. Found: C, 77.86; H, 6.85; N, 4.39.
m), 2.31±2.38 (1H, m), 2.48±2.82 (3H, m), 2.83±2.86 (1H,
m), 3.39 (1H, s), 6.32, 7.79 (each 1H, d, Jˆ5.8 Hz. MS m/z
(%) 189 (M1, 36), 55 (100). Calcd for C11H11NO2: M,
189.0789. Found: m/z 189.0800.
5-Cyano-5-methyl-4,4-diphenyl-2-cyclopentenone (44) and
1-Cyano-2-methoxy-5,5-diphenyl-1,3-cyclopentadiene (45).
A solution of 37 (54 mg; 0.2 mmol) in DMF (3 ml) was
added NaH (12 mg; 0.3 mmol) and iodomethane
(0.025 ml; 0.4 mmol). The suspension was stirred at room
temperature for 30 min and the reaction was quenched by
sat. aq. NH4Cl. The whole was extracted with AcOEt and
after the usual workup followed by silica gel column chro-
matography to give 44 (35 mg; 63%) and 45 (21 mg; 37%).
44: Colorless crystals; mp 133±1348C (AcOEt±hexane); IR
Acknowledgements
We thank Dr Takasi Watanabe and Dr Yasuo Ohtsuka of
Pharmaceutical Research Center, Meiji Seika Kaisha Ltd,
for X-ray crystallographic analysis of 7. This work was
supported by a Grant-in-Aid for Scienti®c Research No.
11640545 from the Ministry of Education, Science, Sports
and Culture, Japan, which is gratefully acknowledged.
1
(KBr) 2242 (CN), 1720 (CO), 706, 699 cm21; H NMR d
References
1.20 (3H, s), 6.23, 7.95 (each 1H, d, Jˆ5.8 Hz), 7.0±7.5
(10H, m). MS m/z (%) 273 (M1, 100), 258 (38), 230 (26).
Calcd for C19H15NO: M, 273.1153. Found: m/z 273.1154.
45: Colorless oil; IR (neat) 2197 (CN), 1614, 1375,
1. Some recent reviews and
a
book for cyclization:
(a) Blumenkopf, T. A.; Overman, L. E. Chem. Rev. 1986, 86,
857. (b) Ho, T.-L. Carbocycle Construction in Terpene Synthesis;
VCH: Weinheim, 1988. (c) Thebtaranonth, C.; Thebtaranonth, Y.
Tetrahedron 1990, 46, 1385. (d) Petasis, N. A.; Patane, M. A.
Tetrahedron 1992, 48, 5757. (e) Booker-Milburn, K. I.; Sharpe,
J. J. Chem. Soc., Perkin Trans. 1 1998, 983.
1
699 cm21; H NMR d 4.21 (3H, s), 6.20, 6.96 (each 1H,
d, Jˆ5.8 Hz), 7.2±7.4 (10H, m). MS m/z (%) 273 (M1,
100), 258 (55), 230 (38). Calcd for C19H15NO: M,
273.1152. Found: m/z 273.1151.
2. (a) Posner, G. H. Chem. Rev. 1986, 86, 831. (b) Ihara, M.;
Fukumoto, K. J. Syn. Org. Chem. Jpn 1986, 44, 96. (c) Bunce,
R. A. Tetrahedron 1995, 51, 13103. (d) Padwa, A.; Weingarten,
M. D. Chem. Rev. 1996, 96, 223. (e) Grigg, R., Ed. Cascade
Reactions; Tetrahedron Symposia-in-Print Number 62:
Tetrahedron 1996, 52, 11385±11664.
1-Cyano-2-pentoxy-5,5-diphenyl-1,3-cyclopentadiene (46).
This compound was synthesized from 37 and 1-iodopentane
as described for 44. Colorless oil; IR (neat) 2197 (CN),
1
1611, 1292, 698 cm21; H NMR d 0.92 (3H, t, Jˆ7.1 Hz),
1.3±1.4 (4H, m), 1.78 (2H, quint, Jˆ8.1 Hz), 4.48 (2H, t,
Jˆ6.6 Hz), 6.21, 6.95 (each 1H, d, Jˆ5.6 Hz), 7.2±7.4
(10H, m). MS m/z (%) 329 (M1, 23), 259 (100), 231 (45).
Calcd for C23H23NO: M, 329.1777. Found: m/z 329.1768.
3. (a) Satoh, T.; Hayashi, Y.; Yamakawa, K. Bull. Chem. Soc. Jpn
1993, 66, 1866. (b) Satoh, T.; Takano, K.; Someya, H.; Matsuda,
K. Tetrahedron Lett. 1995, 36, 7097. (c) Satoh, T.; Takano, K.;
Ota, H.; Someya, H.; Matsuda, K.; Koyama, M. Tetrahedron 1998,
54, 5557.
4-Cyano-3,3-diphenylcyclopentene (47). A solution of 46
(47.7 mg; 0.145 mmol) in THF (1 ml) was added to a
suspension of LiAlH4 (12.3 mg; 0.3 mmol) at 2788C. The
temperature of the reaction mixture was gradually allowed
to warm to room temperature for 2 h, then it was stirred for
3 h. The reaction was quenched by adding AcOEt and the
whole was extracted with AcOEt and washed with sat. aq.
NH4Cl. The product was isolated by silica gel column chro-
matography to give 47 (18.5 mg; 52%) as colorless oil. IR
(neat) 2240 (CN), 1494, 1446, 700 cm21; 1H NMR d 2.82±
2.98 (2H, m), 3.82 (1H, t, Jˆ8.6 Hz), 6.00±6.03 (1H, m),
6.21±6.24 (1H, m), 7.1±7.4 (10H, m). MS m/z (%) 245 (M1,
57), 205 (42), 192 (100). Calcd for C18H15N: M, 245.1204.
Found: m/z 245.1206.
4. Preliminary results of this study were reported as a communica-
tion: Satoh, T.; Ota, H.; Tetrahedron Lett. 1999, 40, 2977.
5. Dolphin, D.; Wick, A. Tabulation of Infrared Spectral Data,
Wiley: New York, 1977; pp 123±130.
6. Formula: C18H14N2 (M.W. 258.3). Crystal system: triclinic.
Ê
Space group: P-1 (#2). Cell: aˆ8.768, bˆ12.142, cˆ7.068 (A)
Ê 3
gˆ98.508, bˆ90.668, gˆ106.758; Zˆ2, Vˆ710 (A ), dˆ1.21.
Final R-valueˆ4.0% (Rwˆ5.8%).
7. Some reviews and a monograph concerning carbene and
carbenoids: Parham, W. E.; Schweizer, E. E. Org. React. 1963,
13, 55. Kirmse, W. Carbene Chemistry; Academic: New York,
1971. Kobrich, V. G. Angew. Chem., Int. Ed. Engl. 1972, 11,
473. Burke, S. D.; Grieco, P. Org. React. 1979, 26, 361. Schaefer
III, H. F. Acc. Chem. Res. 1979, 12, 288. Wynberg, H.; Meijer, E.
W. Org. React. 1982, 28, 1. Oku, A.; Harada, T. J. Syn. Org. Chem.
Jpn 1986, 44, 736. Oku, A. J. Syn. Org. Chem. Jpn 1990, 48, 710.
Padwa, A.; Krumpe, K. E. Tetrahedron 1992, 48, 5385.
Spiro[4.5]dec-1-ene-3,8-dione (48) and 4-cyanospiro[4.5]-
dec-1-ene-3,8-dione (49). To a solution of 23 (41 mg;
0.18 mmol) in a mixture of 1,4-dioxane (2 ml) and water
(2 ml) was added 2 ml of 85% H3PO4. The reaction mixture
was stirred for 24 h at 1508C (bath temperature) to give 48
(20 mg; 69 %) and 49 (10 mg; 31%). 48: Colorless crystals;
mp 95±988C (AcOEt±hexane); IR (KBr) 1706 (CO), 1675,
8. (a) Baldwin, S. J. Org. Chem. 1961, 26, 3280. (b) Baldwin, S.
J. Org. Chem. 1961, 26, 3288. (c) Schaefer, J. P.; Bloom®eld, J.
J. Org. React. 1967, 15, 1. (d) Brown, C. A. Synthesis 1975, 326.
(e) Mundy, B. P.; Ellerd, M. G. Name Reactions and Reagents in
Organic Synthesis; Wiley: New York, 1988; pp 208±209.
(e) Davis, B. R.; Garratt, P. J. In Comprehensive Organic
1
969, 824 cm21; H NMR d 1.85±1.92 (2H, m), 1.98±2.06
(2H, m), 2.47±2.49 (6H, m), 6.18, 7.60 (each 1H, d,

5122
T. Satoh, H. Ota / Tetrahedron 56 (2000) 5113±5122
Synthesis; Trost, B. M., Heathcock, C., Eds.; Pergamon: Oxford,
1991; Vol. 2, p 848. (f) Takaya, H.; Naota, T.; Murahashi, S-i.
J. Am. Chem. Soc. 1998, 120, 4244.
(a) Martin, S. F. Tetrahedron 1980, 36, 419. (b) Sannigrahi, M.
Tetrahedron 1999, 55, 9007.
10. Horning, E. C.; Horning, M. G.; Platt, E. J. J. Am. Chem. Soc.
1948, 70, 2072.
9. Recent reviews for the synthesis of spirocyclic compounds: