Cyclopropanation of vinylidenecyclopropanes. Synthesis of 1-(dihalomethylene)spiropentanes

Article abstract of DOI:10.1021/jo0301595

Synthesis of 1-(dihalomethylene)spiropentanes via cyclopropylidenecyclopropanes generated by cyclopropanation of vinylidenecyclopropanes by dihalocarbenes is described. Reaction of diarylvinylidenecyclopropanes with dibromocarbene and dichlorocarbene excl

Full text of DOI:10.1021/jo0301595

Cyclop r op a n a tion of Vin ylid en ecyclop r op a n es. Syn th esis of
1-(Dih a lom eth ylen e)sp ir op en ta n es
Hajime Maeda, Takayoshi Hirai, Akira Sugimoto, and Kazuhiko Mizuno*
Department of Applied Chemistry, Graduate School of Engineering, Osaka Prefecture University,
1-1 Gakuen-cho, Sakai, Osaka 599-8531, J apan
mizuno@chem.osakafu-u.ac.jp
Received May 12, 2003
Synthesis of 1-(dihalomethylene)spiropentanes via cyclopropylidenecyclopropanes generated by
cyclopropanation of vinylidenecyclopropanes by dihalocarbenes is described. Reaction of diarylvin-
ylidenecyclopropanes with dibromocarbene and dichlorocarbene exclusively gave 1-(dihalomethyl-
ene)spiropentanes in high yields. Reaction of monoarylvinylidenecyclopropanes with dihalocarbenes
afforded cyclopropylidenecyclopropanes as the major product with the formation of a small amount
of 1-(dihalomethylene)spiropentanes. The efficiency of the thermal rearrangement from the
cyclopropylidenecyclopropanes to the 1-(dihalomethylene)spiropentane derivatives depended on the
substituents and the reaction temperature. Reaction of diarylvinylidenecyclopropanes with diphen-
ylcarbene and phenylthiocarbene gave the corresponding spiropentane derivatives. This type of
thermal rearrangement was applicable to the cyclopropanation of 1,1-diarylallenes.
In tr od u ction
vinylidenecyclopropanes. We then focused our attention
on the reactivity of carbenes to allene unit of vinylidene-
cyclopropanes.6 We found that the addition of dihalocar-
benes to the allenyl bond of vinylidenecyclopropanes
proceeds regioselectively and that the subsequent ther-
mal rearrangement of the methylenecyclopropane unit
of the initial adducts occurs at ambient temperature to
Thermal reactions and skeletal conversions of strained
small-ring hydrocarbons have been a subject of consider-
able attention from synthetic and mechanistic viewpoints.
Thermolyses of methylenecyclopropanes1 and cyclo-
propylidenecyclopropanes1d,2 have been well investigated
to give rearranged products via trimethylenemethane
intermediates, but the thermal rearrangement often
requires severe conditions at relatively high temp-
erature.1a-e,g,h,j,k,2 Although addition reaction of carbenes
to allenes is one of the straightforward methods for the
synthesis of methylenecyclopropanes,3 it is difficult to
control the regiochemistry of products3h,j,k,m,o,p and further
addition of carbenes to the methylenecyclopropanes to
give spiropentane derivatives.3d,f-h,k,l,p,r,t,w On the other
hand, we and other groups have reported a few examples
of thermal1d,4 and photochemical5 skeletal conversions of
(3) (a) Ullman, E. F.; Fanshawe, W. J . J . Am. Chem. Soc. 1961, 83,
2379-2383. (b) Meinwald, J .; Wheeler, J . W.; Nimetz, A. A.; Liu, J . S.
J . Org. Chem. 1965, 30, 1038-1046. (c) Be´zaguet, A.; Bertrand, M.
Compt. Rend. Acad. Sci. Paris 1965, 261, 1695-1698. (d) Skattebφl,
L. Tetrahedron Lett. 1965, 2175-2179. (e) Bezaguet, A.; Bertrand, M.
Compt. Rend. Acad. Sci. Paris, Ser. C 1966, 262, 428-430. (f) Battioni-
Savignat, P.; Voquang, Y.; Voquang, L. Bull. Soc. Chim. Fr. 1967,
3929-3930. (g) Noyori, R.; Takaya, H.; Nakanisi, Y.; Nozaki, H. Can.
J . Chem. 1969, 47, 1242-1245. (h) Battioni, P.; Vo-Quang, L.;
Vo-Quang, Y. Bull. Soc. Chim. Fr. 1970, 3938-3942. (i) Dehmlow, E.
V.; Ezimora, G. C. Tetrahedron Lett. 1970, 4047-4050. (j) Dehmlow,
E. V.; Scho¨nefeld, J . Liebigs Ann. Chem. 1971, 744, 42-50. (k)
Heinrich, F.; Lu¨ttke, W. Angew. Chem. 1972, 84, 263-265. (l)
Greibrokk, T. Acta Chem. Scand. 1973, 27, 3207-3210. (m) Creary,
X. J . Am. Chem. Soc. 1977, 99, 7632-7639. (n) Slobodin, Ya. M.;
EÄ genburg, I. Z.; Khachaturov, A. S. Zh. Org. Khim. 1978, 14, 871-
872. (o) Creary, X. J . Org. Chem. 1978, 43, 1777-1783. (p) Kaufmann,
D.; Meijere, A. Tetrahedron Lett. 1979, 783-786. (q) Creary, X. J . Am.
Chem. Soc. 1980, 102, 1611-1618. (r) Kostikov, R. R.; Vorob’eva, I.
S.; Molchanov, A. P. Zh. Org. Khim. 1983, 19, 256-262. (s) Kostikov,
R. R.; Molchanov, A. P.; Nagi, Sh. M. Zh. Org. Khim. 1983, 19, 1437-
1444. (t) Zefirov, N. S.; Kozhushkov, S. I.; Kuznetsova, T. S.; Lukin,
K. A.; Kazimirchik, I. V. Zh. Org. Khim. 1988, 24, 673-678. (u) Fischer,
H.; Bidell, W.; Hofmann, J . J . Chem. Soc., Chem. Commun. 1990, 858-
859. (v) Singleton, D. A.; Church, K. M. J . Org. Chem. 1990, 55, 4780-
4782. (w) Lukin, K. A.; Masunova, A. Yu.; Ugrak, B. I.; Zefirov, N. S.
Tetrahedron 1991, 47, 5769-5780. (x) Santelli-Rouvier, C.; Santelli,
M. Tetrahedron Lett. 1992, 33, 7843-7844. (y) Santelli-Rouvier, C.;
Toupet, L.; Santelli, M. J . Org. Chem. 1997, 62, 9039-9047.
(1) (a) Chesick, J . P. J . Am. Chem. Soc. 1963, 85, 2720-2723. (b)
Gajewski, J . J . J . Am. Chem. Soc. 1968, 90, 7178-7179. (c) Doering,
W. E.; Roth, H. D. Tetrahedron 1970, 26, 2825-2835. (d) Paulson, D.
R.; Crandall, J . K.; Bunnell, C. A. J . Org. Chem. 1970, 35, 3708-3714.
(e) Gajewski, J . J . J . Am. Chem. Soc. 1971, 93, 4450-4458. (f) Dowd,
P. Acc. Chem. Res. 1972, 5, 242-248. (g) Dolbier, W. R., J r.; Fielder,
T. H., J r. J . Am. Chem. Soc. 1978, 100, 5577-5578. (h) Dowd, P.; Chow,
M. Tetrahedron 1982, 38, 799-807. (i) Dallas, B. K.; Hughes, R. P.;
Schumann, K. J . Am. Chem. Soc. 1982, 104, 5380-5383. (j) Garfinkle,
M. J . Chem. Soc., Faraday Trans. 1 1985, 717-725. (k) Dolbier, W.
R., J r.; Seabury, M.; Daly, D.; Smart, B. E. J . Org. Chem. 1986, 51,
974-979. (l) Creary, X.; Mehrsheikh-Mohammadi, M. E. J . Org. Chem.
1986, 51, 2664-2668. (m) Creary, X.; Mehrsheikh-Mohammadi, M. E.;
McDonald, S. J . Org. Chem. 1987, 52, 3254-3263. (n) Creary, X.; Sky,
A. F.; Mehrsheikh-Mohammadi, M. E. Tetrahedron Lett. 1988, 29,
6839-6842. (o) Creary, X.; Mehrsheikh-Mohammadi, M. E.; McDonald,
S. J . Org. Chem. 1989, 54, 2904-2910.
(4) (a) Hendrick, M. E.; Hardie, J . A.; J ones, M., J r. J . Org. Chem.
1971, 36, 3061-3062. (b) Patrick, T. B.; Haynie, E. C.; Probst, W. J .
J . Org. Chem. 1972, 37, 1553-1556. (c) Sadler, I. H.; Stewart, J . A. G.
J . Chem. Soc., Perkin Trans. 2 1973, 278-288. (d) Sugita, H.; Mizuno,
K.; Saito, T.; Isagawa, K.; Otsuji, Y. Tetrahedron Lett. 1992, 33, 2539-
2542. (e) Mizuno, K.; Sugita, H.; Kamada, T.; Otsuji, Y. Chem. Lett.
1994, 449-452.
(2) (a) Dolbier, W. R., J r. Tetrahedron Lett. 1968, 393-396. (b)
Dolbier, W. R., J r.; Akiba, K.; Riemann, J . M.; Harmon, C. A.; Bertrand,
M.; Bezaguet, A.; Santelli, M. J . Am. Chem. Soc. 1971, 93, 3933-3940.
(c) Denis, J . M.; Perchec, P. L.; Conia, J . M. Tetrahedron 1977, 33,
399-408. (d) Kostikov, R. R.; Molchanov, A. P.; Vasil’eva, I. A.;
Slobodin, Ya. M. Zh. Org. Khim. 1977, 13, 2541-2547.
10.1021/jo0301595 CCC: $25.00 © 2003 American Chemical Society
Published on Web 08/30/2003
7700
J . Org. Chem. 2003, 68, 7700-7706

Cyclopropanation of Vinylidenecyclopropanes
TABLE 1. Rea ction of Dia r ylvin ylid en ecyclop r op a n es a n d Dia r yla llen es w ith Ca r ben esa
a
Conditions: substrate (0.06 mol/L), precursor of carbene (5 equiv based on 1 or 6), NaOH powder (over 20 equiv based on 1 or 6),
PhCH2Et3N+Cl- (0.1 equiv based on 1 or 6), benzene, rt, 5 h. Isolated yield. c t-BuOK (1.2 equiv based on 1a ) and 18-crown-6 (1 equiv
b
based on 1a ) were used instead of NaOH and PhCH2Et3N+Cl-.
SCHEME 1
give 1-(dihalomethylene)spiropentane derivatives in high
yields.
Resu lts a n d Discu ssion
To a benzene solution containing 1-diphenylvinylidene-
2,2,3,3-tetramethylcyclopropane 1a 7 were added a large
excess of tribromomethane, NaOH powder, and a cata-
lytic amount of PhCH2Et3N+Cl- (BTEAC), and the mix-
ture was vigorously stirred for 5 h at room temperature.
Purification of the resulting mixture afforded a spiro-
pentane derivative 2a in 73% isolated yield (Scheme 1).
Structure of 2a was determined by its spectral and
analytical data and confirmed by X-ray analysis (Figure
1).
To survey the generality of this reaction, we investi-
gated the reactions of vinylidenecyclopropanes 1a -f with
dibromocarbene and dichlorocarbene (Table 1).8 Reactions
of p-chloro and p-methoxy derivatives 1b-d with dibro-
mocarbene proceeded efficiently to give spiropentane
derivatives 2b-d in high yields. Reaction of 1a with
dichlorocarbene gave the corresponding 1-(dichlorometh-
ylene)spiropentane 3a in a nearly quantitative yield. 2,2-
Diphenyl-substituted vinylidenecyclopropane 1e and flu-
orene derivative 1f also reacted with dibromocarbene to
give 2e,f, respectively. Reactivity of other carbenes was
also investigated. Vinylidenecyclopropane 1a reacted
with diphenylcarbene to give a spiropentane derivative
4 in 41% isolated yield. Reaction of 1a with phenylthio-
carbene also gave spiropentane derivative (E)-5 stereo-
selectively. The structures of 4 and (E)-5 were confirmed
by X-ray analysis (see the Supporting Information). This
rearrangement is applicable to regioselective cyclopro-
panation of 1,1-diarylallenes. It is noteworthy that the
(5) (a) Akasaka, T.; Misawa, Y.; Ando, W. Tetrahedron Lett. 1990,
31, 1173-1176. (b) Mizuno, K.; Sugita, H.; Isagawa, K.; Goto, M.;
Otsuji, Y. Tetrahedron Lett. 1993, 34, 5737-5738. (c) Mizuno, K.; Nire,
K.; Sugita, H.; Otsuji, Y. Tetrahedron Lett. 1993, 34, 6563-6566. (d)
Mizuno, K.; Sugita, H.; Hirai, T.; Maeda, H. Chem. Lett. 2000, 1144-
1145. (e) Mizuno, K.; Nire, K.; Sugita, H.; Maeda, H. Tetrahedron Lett.
2001, 42, 2689-2692. (f) Mizuno, K.; Maeda, H.; Sugita, H.; Nishioka,
S.; Hirai, T.; Sugimoto, A. Org. Lett. 2001, 3, 581-584. (g) Mizuno, K.;
Sugita, H.; Hirai, T.; Maeda, H.; Otsuji, Y.; Yasuda, M.; Hashiguchi,
M.; Shima, K. Tetrahedron Lett. 2001, 42, 3363-3366. (h) Maeda, H.;
Zhen, L.; Hirai, T.; Mizuno, K. ITE Lett. Batteries, New Technol. Med.
2002, 3, 485-488.
(6) For the reactions of vinylidenecyclopropanes with carbenes and
carbene complexes: (a) Crandall, J . K.; Paulson, D. R.; Bunnell, C. A.
Tetrahedron Lett. 1969, 4217-4220. (b) Hwu, C.-C.; Wang, F.-C.; Yeh,
M.-C. P. J . Organomet. Chem. 1994, 474, 123-128. (c) Billups, W. E.;
Haley, M. M.; Boese, R.; Bla¨ser, D. Tetrahedron 1994, 50, 10693-
10700.
(8) We attempted the reactions in concentrations of diarylvin-
ylidenecyclopropanes from 0.025 to 0.22 mol/L and changed equivalents
of haloform from 2.5 to 100 equiv, but the yields did not change
appreciably. Progress of the reaction was monitored by TLC, and the
reaction was continued until the substrates disappeared.
(7) We have developed a convenient method for the synthesis of
vinylidenecyclopropanes: Isagawa, K.; Mizuno, K.; Sugita, H.; Otsuji,
Y. J . Chem. Soc., Perkin Trans. 1 1991, 2283-2285.
J . Org. Chem, Vol. 68, No. 20, 2003 7701

Maeda et al.
F IGURE 2. ORTEP drawing of 9g: monoclinic, P21/a(#14),
Z ) 4, R ) 0.064, Rw ) 0.077, a ) 16.4629(7) Å, b ) 7.0161(3)
F IGURE 1. ORTEP drawing of 2a : triclinic, P1h(#2), Z ) 2,
R ) 0.047, Rw ) 0.079, a ) 10.2519(8) Å, b ) 10.855(1) Å, c )
10.068(2) Å, a ) 95.415(3)°, â ) 94.831(2)°, γ ) 117.804(7)°, V
) 976.1(2) Å3, Dcalcd ) 1.52 g/cm3.
Å, c ) 16.997(1) Å, â ) 104.488(3)°, V ) 1900.8(1) Å3, Dcalcd
)
1.207 g/cm3.
SCHEME 2
TABLE 2. Syn th esis of
Cyclop r op ylid en ecyclop r op a n esa
run substrate
Ar
R
X
product yieldb (%)
1
2
3
4
5
6
1g
1g
1h
1i
1j
1k
1-naphthyl Me
1-naphthyl Me
Br
Cl
8g
9g
8h
8i
8j
8k
68
79
48
40
69
65
Ph
cyclohexyl Br
Ph
p-ClC6H4
Me
Me
Br
Br
Br
2-naphthyl Me
a
Conditions: 1 (0.06 mol/L), CHX3 (5 equiv based on 1), NaOH
powder (over 20 equiv based on 1), PhCH2Et3N+Cl- (0.1 equiv
based on 1), benzene, rt, 5 h. Isolated yield.
b
F IGURE 3. ORTEP drawing of 3g: monoclinic, C2/c(#15), Z
) 8, R ) 0.040, Rw ) 0.031, a ) 36.678(1) Å, b ) 7.0562(2) Å,
SCHEME 3
c ) 14.5444(3) Å, â ) 104.654(1)°, V ) 3641.7(2) Å3, Dcalcd
)
1.260 g/cm3.
halomethylene)spiropentanes proceeds via the cyclo-
propylidenecyclopropanes 8 (X ) Br) and 9 (X ) Cl) as
an intermediate. The structures of compounds before and
after the thermal rearrangement were confirmed by
spectral and analytical data, especially for the X-ray
analysis of 9g and 3g (Figures 2 and 3).
reaction of diarylallenes 6a ,b with dibromocarbene gave
the rearranged products 7a ,b exclusively.
Then the monoaryl derivatives 1g-k were allowed to
react with dihalocarbenes under the same conditions
(Scheme 2, Table 2). Surprisingly the major product in
the reactions of monoaryl derivatives 1g-k with diha-
locarbenes were changed to the cyclopropylidenecyclo-
propanes 8g-k and 9g. The corresponding 1-(dihalom-
ethylene)spiropentanes 2g-k and 3g were produced as
minor components (<5%), and they can be easily sepa-
rated by HPLC. The isolated cyclopropylidenecyclopro-
panes 8g-k and 9g were converted to spiropentane
derivatives 2g-k and 3g quantitatively in refluxing
toluene for 2 h, respectively (Scheme 3). These results
clearly demonstrate that the reaction of monoarylvin-
ylidenecyclopropanes with dihalocarbenes to give 1-(di-
On the basis of these results, we propose a possible
pathway for the formation of 2 and 3 as shown in Scheme
4. The first step is the regioselective addition of dihalo-
carbene to the allenyl bond of 1 to give the cyclopropy-
lidenecyclopropanes 8 and 9. Then, 8 and 9 rearrange to
the spiropentane derivatives 2 and 3 via trimethylene-
methane intermediates 10 generated by homolytic C-C
bond cleavage of the cyclopropylidenecyclopropanes. The
difference of the products between diaryl derivatives
1a -f and monoaryl derivatives 1g-k clearly indicates
that the rearrangement from 8a -f to 2a -f proceeds
efficiently at room temperature, whereas the rearrange-
7702 J . Org. Chem., Vol. 68, No. 20, 2003

Cyclopropanation of Vinylidenecyclopropanes
TABLE 3. Activa tion En er gies for th e Rea r r a n gem en t
fr om 8g-k , 9g to 2g-k , 3g
SCHEME 4
a
Ea
run substrate
Ar
R
X
product (kJ /mol)
1
2
3
4
5
6
8g
9g
8h
8i
8j
8k
1-naphthyl Me
1-naphthyl Me
Br
Cl
2g
3g
2h
2i
2j
2k
140.0
119.3
107.6
105.5
99.6
Ph
cyclohexyl Br
Ph
p-ClC6H4
Me
Me
Br
Br
Br
2-naphthyl Me
93.6
a
Activation energies were calculated by Arrhenius plots of
reactions in toluene-d8 at 65-105 °C.
SCHEME 5
SCHEME 6
ment from 8g-k to 2g-k requires more elevated tem-
perature.
In general, rearrangement of alkyl-substituted meth-
ylenecyclopropanes via trimethylenemethane intermedi-
ate proceeds by photoirradiation9 or heating at high
temperature.1a-e,g,h,j,k,2,3s,4a-c,6a Substitution of methyl-
enecyclopropanes by aryl groups or halogen atoms makes
the temperature of the rearrangement lower.1g,l-o,3o,q,4a-c
Thermal rearrangement of alkyl-substituted cycloprop-
ylidenecyclopropanes to spiropentanes also requires high
temperature (>170 °C),1d,2a-c but the rearrangement of
halogenated derivatives proceeds under relatively mild
conditions (100-160 °C).2d In contrast, to the best of our
knowledge, the rearrangement of 1a -f to 2a -f occurring
at room temperature is a rare case.10
To clarify the mechanism of this rearrangement, the
structure-reactivity relationship was evaluated by ac-
tivation energies calculated by Arrhenius plot of the
rearrangement from 8g-k , 9g to 2g-k , 3g in toluene-
d8 (Scheme 5, Table 3). Rotation of the aromatic ring of
8, 9 might be important because the interaction of
π-orbitals of the aromatic ring and σ-orbital of the
cyclopropane ring seems to accelerate the rearrangement.
This assumption is supported by the fact that the
activation energy decreased in the order of 8g > 8h > 8i
(runs 1-4 in Table 3). The rotation of naphthyl ring of
8g is suppressed by the interaction between the hydrogen
atom on peri-position of the 1-naphthyl ring and the
methyl group. Rotation of phenyl ring of 8h is suppressed
by the steric hindrance of cyclohexyl group compared
with that of methyl group of 8i. The fluorene derivative
1f in which aromatic rings cannot rotate gave only
spiropentane derivative 2f at room temperature (Table
1, entry 7). This result also supports the above assump-
tion.
The second factor related to the efficiency of the
rearrangement may be radical stabilization ability of the
substituents. Activation energies required for the rear-
rangement of 8j and 8k were lower than that of 8i. The
p-chlorophenyl group of 8j and 2-naphthyl group of 8k
might act to stabilize the intermediate 10 than the
stabilization by the phenyl group of 8i.11
The radical stabilization effect on the intermediate in
this rearrangement was further supported by the regio-
selective cyclopropanation of vinylidenecyclopropane 1e
with dibromocarbene (Table 1, run 6, and Scheme 6).
When dibromocarbene adds to the allenyl bond of vi-
nylidenecyclopropane 1e, cyclopropylidenecyclopropane
intermediate 8e should be formed. As the result of this
reaction, only spiropentane derivative 2e was produced
without any formation of 2e′. This result suggests that
the C-C bond cleavage of 8e occurred only at the
dibromo-substituted cyclopropane ring; hence, we con-
cluded that effect of halogen atoms to this thermal
rearrangement is mainly due to their radical stabilization
ability.2d
(9) (a) Kende, A. S.; Goldschmidt, Z.; Smith, R. F. J . Am. Chem.
Soc. 1970, 92, 7606-7607. (b) Yamaguchi, T.; Irie, M.; Yoshida, H.
Chem. Lett. 1973, 975-978. (c) Dowd, P.; Chow, M. J . Am. Chem. Soc.
1977, 99, 6438-6440. (d) Takahashi, Y.; Miyashi, T.; Mukai, T. J . Am.
Chem. Soc. 1983, 105, 6511-6513. (e) Miyashi, T.; Takahashi, Y.;
Mukai, T.; Roth, H. D.; Schilling, M. L. M. J . Am. Chem. Soc. 1985,
107, 1079-1080. (f) Baum, T.; Rossi, A.; Srinivasan, R. J . Am. Chem.
Soc. 1985, 107, 4411-4415. (g) Miyashi, T.; Kamata, M.; Mukai, T. J .
Am. Chem. Soc. 1986, 108, 2755-2757. (h) Miyashi, T.; Kamata, M.;
Mukai, T. J . Am. Chem. Soc. 1987, 109, 2780-2788. (i) Komaguchi,
K.; Shiotani, M.; Lund, A. Chem. Phys. Lett. 1997, 265, 217-223. (j)
Ikeda, H.; Nakamura, T.; Miyashi, T.; Goodman, J . L.; Akiyama, K.;
Tero-Kubota, S.; Houmam, A.; Wayner, D. D. M. J . Am. Chem. Soc.
1998, 120, 5832-5833. (k) Miyashi, T.; Ikeda, H.; Takahashi, Y.;
Akiyama, K. In Advances in Electron-Transfer Chemistry; Mariano,
P. S., Ed.; J AI Press Inc.: Stamford, 1999; Vol. 6, pp 1-39. (l) Maier,
G.; Senger, S. Eur. J . Org. Chem. 1999, 1291-1294.
Con clu sion
In conclusion, cyclopropanation of diarylvinylidenecy-
clopropanes by dihalocarbenes gave 1-(dihalomethylene)-
(10) Creary et al. suggested that the two phenyl groups in an
analogous methylenecyclopropane should allow the rearrangement to
occur below room temperature. The methylenecyclopropane rearrange-
ment of systems substituted with phenyl and methoxy groups occur
readily at room temperature. See refs 1m and 3q.
(11) The radical-stabilizing effect of the 2-naphthyl group and
halogen atoms has been discussed in refs 1l-n.
J . Org. Chem, Vol. 68, No. 20, 2003 7703

Maeda et al.
stirred for 5 h. Purification of the resulting mixture by use of
column chromatography on silica gel followed by recrystalli-
zation from methanol afforded methylenespiropentane deriva-
tive 2a . Other compounds were synthesized by a similar
method.8
spiropentanes in high yields via cyclopropylidenecyclo-
propane intermediates. In the case of monoaryl derivatives,
the rearrangement can be controlled by the substituents
and the reaction temperature. Methylenespiropentane
frameworks are important intermediates,2c,6a,9l,12,13 espe-
cially for the synthesis of spiro-condensed cyclo-
propanes.3w,14 It is expected that the present study will
provide useful information for the synthesis of cyclopro-
pylidenecyclopropanes and spiropentane derivatives.
1-D i b r o m o m e t h y le n e -4,4,5,5-t e t r a m e t h y l-2,2-d i -
p h en ylsp ir o[2.2]p en ta n e (2a ): mp 148-149 °C (methanol);
1H NMR (300 MHz, CDCl3) δ 7.34-7.22 (m, 10 H), 1.39 (s, 6
H), 0.91 (s, 6 H); 13C NMR (75 MHz, CDCl3) δ 142.40, 138.23,
128.51, 127.83, 126.32, 68.01, 50.57, 46.77, 31.69, 21.48, 20.13;
IR (KBr) 2951, 2916, 2863, 1602, 1494, 1443, 1375 cm-1; UV
(cyclohexane) λmax 220 nm (shoulder, log ꢀ ) 4.30). Anal. Calcd
for C22H22Br2: C, 59.22; H, 4.97. Found: C, 59.19; H, 5.12.
1,1-Bis(4-ch lor op h en yl)-2-d ib r om om et h ylen e-4,4,5,5-
tetr a m eth ylsp ir o[2.2]p en ta n e (2b): mp 138.5-139.5 °C
(methanol); 1H NMR (300 MHz, CDCl3) δ 7.30-7.14 (m, 8 H),
1.38 (s, 6 H), 0.92 (s, 6 H); 13C NMR (75 MHz, CDCl3) δ 141.47,
136.47, 132.40, 129.75, 128.21, 68.79, 50.67, 45.61, 31.94,
21.44, 20.19; IR (KBr) 2998, 2973, 2948, 2917, 2864, 1901, 1490
cm-1; UV (cyclohexane) λmax 229 nm (log ꢀ ) 4.46). Anal. Calcd
for C22H20Br2Cl2: C, 51.30; H, 3.91. Found: C, 50.95; H, 4.06.
1,6-Dim et h ylb icyclo[4.1.0]h ep t a n e-7-sp ir o-2′,2′-b is(4-
ch lor op h en yl)-3′-(d ibr om om eth ylen e)cyclop r op a n e (2c):
mp 126-127 °C (methanol); 1H NMR (300 MHz, CDCl3) δ
7.32-7.14 (m, 8 H), 1.42-0.87 (m, 14 H); 13C NMR (75 MHz,
CDCl3) δ 141.06, 136.23, 132.43, 129.68, 128.28, 68.62, 48.77,
46.06, 32.50, 28.88, 21.77, 21.26; IR (KBr): 2933, 2858, 1735,
1560, 1491, 1396 cm-1; UV (cyclohexane) λmax 229 nm (log ꢀ )
4.46). Anal. Calcd for C24H22Br2Cl2: C, 53.27; H, 4.10. Found:
C, 53.04; H, 4.17.
Exp er im en ta l Section
Cyclop r op a n a tion of Vin ylid en ecyclop r op a n es. To a
benzene solution containing vinylidenecyclopropane 1a (500
mg) were added a large excess of tribromomethane (0.5 mL),
PhCH2Et3N+Cl- (BTEAC, 0.1 equiv) as a phase-transfer agent,
and a large excess of NaOH (powder), and the mixture was
(12) For synthesis and reactions of spiropentane derivatives: (a)
Zelinsky, N. Chem. Ber. 1913, 46, 160-172. (b) Murray, M. J .;
Stevenson, E. H. J . Am. Chem. Soc. 1944, 66, 812-816. (c) Slabey, V.
A. J . Am. Chem. Soc. 1946, 68, 1335-1336. (d) Goubeau, J .; Sander,
I. Angew. Chem. 1949, 82, 176-183. (e) House, H. O.; Lord, R. C.; Rao,
H. S. J . Org. Chem. 1956, 21, 1487-1491. (f) Applequist, D. E.; Fanta,
G. F.; Henrikson, B. W. J . Org. Chem. 1958, 23, 1715-1716. (g)
Applequist, D. E.; J ohnston, M. R.; Fisher, F. J . Am. Chem. Soc. 1970,
92, 4614-4617. (h) Northington, D. J .; J ones, W. M. Tetrahedron Lett.
1971, 317-320. (i) Seyferth, D.; Lambert, R. L., J r. J . Organomet.
Chem. 1975, 91, 31-45. (j) Takahashi, Y.; Ohaku, H.; Morishima, S.;
Suzuki, T.; Ikeda, H.; Miyashi, T. J . Chem. Soc., Perkin Trans. 1 1996,
319-325.
(13) For synthesis and reactions of methylenespiropentane deriva-
tives, see: (a) Skattebφl, L. J . Org. Chem. 1966, 31, 2789-2794. (b)
Ko¨brich, G.; Heinemann, H.; Zu¨ndorf, W. Tetrahedron 1967, 23, 565-
584. (c) Roth, W. R.; Erker, G. Angew. Chem. 1973, 85, 512-512. (d)
Grimme, W.; Rother, H.-J . Angew. Chem. 1973, 85, 512-514. (e) Arora,
S.; Binger, P. Synthesis 1974, 801-803. (f) de Meijere, A. Chem. Ber.
1974, 107, 1702-1713. (g) Mu¨ller, C.; Stier, F.; Weyerstahl, P. Chem.
Ber. 1977, 110, 124-137. (h) Lahti, P. M.; Berson, J . A. J . Am. Chem.
Soc. 1981, 103, 7011-7012. (i) Fitjer, L. Chem. Ber. 1982, 115, 1035-
1046. (j) Bushby, R. J .; J esudason, M. V.; Pollard, M. D.; Shuhaibar,
K. F. J . Chem. Soc., Perkin Trans. 1 1982, 2647-2654. (k) Bertrand,
M.; Tubul, A.; Ghiglione, C. J . Chem. Res., Miniprint 1983, 2274-
2288. (l) Bushby, R. J .; Mann, S.; J esudason, M. V. Tetrahedron Lett.
1983, 24, 4743-4744. (m) Bushby, R. J .; Mann, S.; J esudason, M. V.
J . Chem. Soc., Perkin Trans. 1 1984, 2457-2464. (n) Pietruszka, J .;
Ko¨nig, W. A.; Maelger, H.; Kopf, J . Chem. Ber. 1993, 126, 159-166.
(o) de Meijere, A.; Kozhushkov, S. I.; Spaeth, T.; Zefirov, N. S. J . Org.
Chem. 1993, 58, 502-505. (p) Wessjohann, L.; Giller, K.; Zuck, B.;
Skattebφl, L.; de Meijere, A. J . Org. Chem. 1993, 58, 6442-6450. (q)
Miebach, T.; Brinker, U. H. J . Org. Chem. 1993, 58, 6524-6525. (r)
Gajewski, J . J .; Paul, G. C.; Chang, M. J .; Gortva, A. M. J . Am. Chem.
Soc. 1994, 116, 5150-5154. (s) Kozhushkov, S. I.; Brandl, M.; Yufit,
D. S.; Machinek, R.; de Meijere, A. Liebigs Ann./ Recueil 1997, 2197-
2204. (t) Brandl, M.; Kozhushkov, S. I.; Bra¨se, S.; de Meijere, A. Eur.
J . Org. Chem. 1998, 453-457. (u) de Meijere, A.; Ernst, K.; Zuck, B.;
Brandl, M.; Kozhushkov, S. I.; Tamm, M.; Yufit, D. S.; Howard, J . A.
K.; Labahn, T. Eur. J . Org. Chem. 1999, 3105-3115. (v) Miyazawa,
K.; Yufit, D. S.; Howard, J . A. K.; de Meijere, A. Eur. J . Org. Chem.
2000, 4109-4117.
(14) (a) Fitjer, L.; Conia, J .-M. Angew. Chem., Int. Ed. Engl. 1973,
12, 761-762. (b) Zefirov, N. S.; Kozhushkov, S. I.; Kuznetsova, T. S.;
Kokoreva, O. V.; Lukin, K. A.; Ugrak, B. I.; Tratch, S. S. J . Am. Chem.
Soc. 1990, 112, 7702-7707. (c) Zo¨llner, S.; Buchholz, H.; Boese, R.;
Gleiter, R.; de Meijere, A. Angew. Chem., Int. Ed. Engl. 1991, 30, 1518-
1520. (d) Lukin, K. A.; Kozhushkov, S. I.; Andrievsky, A. A.; Ugrak,
B. I.; Zefirov, N. S. J . Org. Chem. 1991, 56, 6176-6179. (e) Zefirov, N.
S.; Kozhushkov, S. I.; Ugrak, B. I.; Lukin, K. A.; Kokoreva, O. V.; Yufit,
D. S.; Struchkov, Y. T.; Zoellner, S.; Boese, R.; de Meijere, A. J . Org.
Chem. 1992, 57, 701-708. (f) Kozhushkov, S. I.; Haumann, T.; Boese,
R.; de Meijere, A. Angew. Chem., Int. Ed. Engl. 1993, 32, 401-403. (g)
de Meijere, A.; Kozhushkov, S. I.; Zefirov, N. S. Synthesis 1993, 681-
683. (h) Zefirov, N. S.; Kuznetsova, T. S.; Eremenko, O. V.; Kokoreva,
O. V.; Zatonsky, G.; Ugrak, B. I. J . Org. Chem. 1994, 59, 4087-4089.
(i) Beckhaus, H.-D.; Ru¨chardt, C.; Kozhushkov, S. I.; Belov, V. N.;
Verevkin, S. P.; de Meijere, A. J . Am. Chem. Soc. 1995, 117, 11854-
11860. (j) de Meijere, A.; Khlebnikov, A. F.; Kostikov, R. R.; Kozhush-
kov, S. I.; Schreiner, P. R.; Wittkopp, A.; Yufit, D. S. Angew. Chem.,
Int. Ed. 1999, 38, 3474-3477. (k) Seebach, M.; Kozhushkov, S. I.;
Boese, R.; Benet-Buchholz, J .; Yufit, D. S.; Howard, J . A. K.; de Meijere,
A. Angew. Chem., Int. Ed. 2000, 39, 2495-2498.
1-Dibr om om eth ylen e-2,2-bis(4-m eth oxyph en yl)-4,4,5,5-
tetr a m eth ylsp ir o[2.2]p en ta n e (2d ): oil; 1H NMR (300 MHz,
CDCl3) δ 7.18-1.15 (m, 4 H), 6.85-6.82 (m, 4 H), 1.37 (s, 6
H), 0.93 (s, 6 H); 13C NMR (75 MHz, CDCl3) δ 157.96, 142.85,
130.61, 129.56, 113.22, 67.30, 55.24, 50.40, 45.78, 31.66, 21.49,
20.25; IR (KBr) 2996, 2951, 2831, 1609, 1511, 1458, 1248 cm-1
;
UV (cyclohexane) λmax 236 nm (log ꢀ ) 4.40).
1-Dib r om om e t h yle n e -2,2,4,4-t e t r a p h e n ylsp ir o[2.2]-
p en ta n e (2e): oil; 1H NMR (300 MHz, CDCl3) δ 7.41-6.96
(m, 18 H), 6.79-6.75 (m, 2 H), 2.54 (d, J ) 5.13 Hz, 1 H), 2.25
(d, J ) 5.13 Hz, 2 H); 13C NMR (75 MHz, CDCl3) δ 141.27,
140.41, 140.15, 138.43, 137.35, 130.00, 128.61, 128.28, 128.22,
127.73, 127.01, 126.96, 126.86, 126.59, 125.86, 71.80, 45.48,
44.40, 41.03, 22.34; IR (KBr) 3057, 3024, 1735, 1601, 1493,
1444 cm-1; UV (cyclohexane) λmax 220 nm (shoulder, log ꢀ )
4.51). Anal. Calcd for C30H22Br2: C, 66.44; H, 4.09. Found: C,
66.73; H, 3.88.
1-D ib r o m o m e t h y le n e -2,4,4,5,5-p e n t a m e t h y l-2-(1-
1
n a p h th yl)sp ir o[2.2]p en ta n e (2g): oil; H NMR (300 MHz,
CDCl3) δ 8.16-8.13 (m, 1 H), 7.86-7.73 (m, 2 H), 7.55-7.26
(m, 4 H), 1.87 (s, 3 H), 1.50 (s, 3 H), 1.45 (s, 3 H), 1.15 (s, 3 H),
0.49 (s, 3 H); 13C NMR (75 MHz, CDCl3) δ 142.80, 135.80,
134.00, 132.42, 128.97, 127.81, 125.49, 125.42, 125.04, 124.95,
66.19, 50.35, 38.33, 32.32, 31.97, 29.79, 21.92, 21.44, 20.31,
20.18, 18.38; IR (KBr) 3005, 2921, 2858 cm-1; UV (cyclohexane)
λmax 284 (log ꢀ ) 3.88), 275 (log ꢀ ) 3.80), 225 nm (log ꢀ )
4.80). Anal. Calcd for C21H22Br2: C, 58.09; H, 5.11. Found: C,
57.95; H, 5.28.
1-Cycloh exyl-2-dibr om om eth ylen e-4,4,5,5-tetr a m eth yl-
1-p h en ylsp ir o[2.2]p en ta n e (2h ): mp 156-156.5 °C (metha-
1
nol); H NMR (300 MHz, CDCl3) δ 7.30-7.15 (m, 5 H), 2.33-
2.26 (m, 1 H), 1.86-1.63 (m, 5 H), 1.43-1.11 (m, 14 H), 0.43
(s, 3 H); 13C NMR (75 MHz, CDCl3) δ 139.75, 138.99, 127.88,
127.43, 125.91, 66.68, 46.89, 46.85, 39.11, 31.57, 31.49, 30.88,
28.83, 27.18, 26.80, 26.65, 21.54, 20.76, 20.46, 18.88; IR (KBr)
3057, 3005, 2979, 2937, 2849 cm-1; UV (cyclohexane) λmax 222
nm (log ꢀ ) 4.27). Anal. Calcd for C22H28Br2: C, 58.42; H, 6.24.
Found: C, 58.16; H, 6.36.
1-Dib r om om et h ylen e-2,4,4,5,5-p en t a m et h yl-2-p h en -
ylsp ir o[2.2]p en ta n e (2i): mp 53.5-54.5 °C (methanol); 1H
NMR (300 MHz, CDCl3) δ 7.32-7.15 (m, 5 H), 1.63 (s, 3 H),
1.36 (s, 3 H), 1.32 (s, 3 H), 1.22 (s, 3 H), 0.66 (s, 3 H); 13C NMR
7704 J . Org. Chem., Vol. 68, No. 20, 2003

Cyclopropanation of Vinylidenecyclopropanes
(75 MHz, CDCl3) δ 140.30, 128.00, 125.92, 125.83, 65.51, 50.49,
37.54, 31.59, 31.50, 31.42, 21.54, 21.29, 19.70, 19.28, 17.33;
IR (KBr) 2952, 2924, 2866, 1375 cm-1; UV (cyclohexane) λmax
223 nm (log ꢀ ) 4.36). Anal. Calcd for C17H20Br2: C, 53.15; H,
5.25. Found: C, 53.53; H, 5.28.
cm-1; UV (cyclohexane) λmax 222 nm (log ꢀ ) 4.34). Anal. Calcd
for C16H12Br2: C, 52.78; H, 3.32. Found: C, 52.63; H, 3.17.
1,1-Bis(p -ch lor op h en yl)-2-(d ib r om om et h ylen e)cyclo-
p r op a n e (7b): mp 110-111 °C (methanol); 1H NMR (300
MHz, C6D6) δ 7.16-7.01 (m, 4 H), 6.99-6.80 (m, 4 H), 1.51 (s,
2 H); 13C NMR (75 MHz, C6D6) δ 138.76, 136.33, 133.50,
129.50, 129.00, 77.22, 42.60, 27.91; IR (KBr) 3100, 3057, 2979,
2918, 2849, 1902, 1745, 1493, 1398 cm-1; UV (cyclohexane)
λmax 230 nm (log ꢀ ) 4.47). Anal. Calcd for C16H10Br2Cl2: C,
44.39; H, 2.33. Found: C, 44.39; H, 2.24.
1-(4-Ch lor op h e n yl)-2-d ib r om om e t h yle n e -1,4,4,5,5-
p en ta m eth ylsp ir o[2.2]p en ta n e (2j): oil; 1H NMR (300 MHz,
CDCl3) δ 7.27-7.24 (m, 2 H), 7.10-7.08 (m, 2 H), 1.60 (s, 3
H), 1.36 (s, 3 H), 1.32 (s, 3 H), 1.21 (s, 3 H), 0.68 (s, 3 H); 13C
NMR (75 MHz, CDCl3) δ 142.70, 139.05, 131.61, 128.18,
127.30, 65.97, 50.53, 37.00, 31.68, 31.62, 21.52, 21.25, 19.66,
2,2-Dib r om o-2′,2′,3,3′,3′-p en t a m et h yl-3-(1-n a p h t h yl)-
1,1′-bicyclop r op ylid en e (8g): mp 128-131 °C dec (metha-
19.41, 17.27; IR (neat) 2987, 2952, 2918, 2866, 1488, 1375 cm-1
;
1
nol); H NMR (300 MHz, CDCl3) δ 8.17-8.12 (m, 1 H), 7.91-
UV (cyclohexane) λmax 230 nm (log ꢀ ) 4.38). Anal. Calcd for
7.88 (m, 1 H), 7.79-7.76 (m, 1 H), 7.66-7.60 (m, 1 H), 7.55-
7.50 (m, 1 H), 7.38-7.26 (m, 2 H), 1.86 (s, 3 H), 1.51 (s, 3 H),
1.39 (s, 3 H), 1.35 (s, 3 H), 1.34 (s, 3 H); 13C NMR (75 MHz,
CDCl3) δ 143.46, 139.15, 134.01, 131.00, 128.59, 127.96, 126.14,
126.05, 125.90, 125.75, 125.19, 121.01, 40.68, 34.91, 26.44,
24.67, 24.33, 21.28, 21.01, 20.59, 20.52; IR (KBr) 3057, 2987,
2923, 2866, 1448, 1370, 1108 cm-1; UV (cyclohexane) λmax 298
(log ꢀ ) 3.60), 286 (log ꢀ ) 3.71), 276 (log ꢀ ) 3.63), 226 nm
(log ꢀ ) 4.63). Anal. Calcd for C21H22Br2: C, 58.09; H, 5.11.
Found: C, 58.43; H, 5.15.
C
17H19Br2Cl: C, 48.78; H, 4.58. Found: C, 48.65; H, 4.99.
1-D ib r o m o m e t h y le n e -2,4,4,5,5-p e n t a m e t h y l-2-(2-
1
n a p h th yl)sp ir o[2.2]p en ta n e (2k ): oil; H NMR (300 MHz,
CDCl3) δ 7.81-7.74 (m, 3 H), 7.66-7.65 (m, 1 H), 7.46-7.42
(m, 2 H), 7.25-7.18 (m, 1 H), 1.74 (s, 3 H), 1.39 (s, 3 H), 1.36
(s, 3 H), 1.24 (s, 3 H), 0.66 (s, 3 H); 13C NMR (75 MHz, CDCl3)
δ 143.40, 138.19, 133.22, 131.81, 127.536, 127.532, 127.41,
125.86, 125.31, 124.60, 124.34, 65.76, 50.44, 37.77, 31.67,
31.56, 21.51, 21.33, 19.73, 19.58, 17.39; IR (NaCl) 3056, 2987,
2952, 2920, 2866, 1735, 1601, 1507, 1458, 1411, 1377 cm-1
;
2,2-Dibr om o-3-cycloh exyl-2′,2′,3′,3′-tetr am eth yl-2-ph en -
yl-1,1′-bicyclop r op ylid en e (8h ): mp 92.5-94 °C dec (metha-
UV (cyclohexane) λmax 288 (log ꢀ ) 3.85), 278 (log ꢀ ) 4.00),
268 (log ꢀ ) 4.01), 228 nm (log ꢀ ) 4.88). Anal. Calcd for C21H22
Br2: C, 58.09; H, 5.11. Found: C, 58.26; H, 5.07.
-
1
nol); H NMR (300 MHz, CDCl3) δ 7.41-7.03 (m, 5 H), 2.19-
2.15 (m, 1 H), 1.76-1.53 (m, 5 H), 1.40 (s, 3 H), 1.35 (s, 3 H),
1.33 (s, 3 H), 1.30-0.80 (m, 8 H); 13C NMR (75 MHz, CDCl3)
δ 141.39, 137.47, 131.11, 130.23, 127.53, 126.78, 121.79, 48.68,
48.45, 34.01, 30.96, 29.23, 26.84, 26.27, 26.05, 24.21, 23.79,
21.57, 21.30, 20.51, 20.44; IR (KBr) 2985, 2927, 2850, 1491,
1445, 1105 cm-1; UV (cyclohexane) λmax 216 nm (log ꢀ ) 4.32).
Anal. Calcd for C22H28Br2: C, 58.42; H, 6.24. Found: C, 58.06;
H, 6.56.
1 -D i c h l o r o m e t h y l e n e -4 ,4 ,5 ,5 -t e t r a m e t h y l -2 ,2 -
d ip h en ylsp ir o[2.2]p en ta n e (3a ): mp 129-130 °C (metha-
1
nol); H NMR (300 MHz, CDCl3) δ 7.30-7.23 (m, 10 H), 1.34
(s, 6 H), 0.94 (s, 6 H); 13C NMR (75 MHz, CDCl3) δ 138.81,
135.05, 128.87, 128.49, 126.36, 105.14, 48.99, 44.46, 31.26,
21.42, 20.12; IR (KBr) 2999, 2949, 2918, 2866, 1560, 1496, 1379
cm-1; UV (cyclohexane) λmax 223 nm (log ꢀ ) 4.35). Anal. Calcd
for C22H22Cl2: C, 73.95; H, 6.21. Found: C, 73.84; H, 6.41.
2,2-Dibr om o-2′,2′,3,3′,3′-p en t a m et h yl-3-p h en yl-1,1′-b i-
cyclop r op ylid en e (8i): mp 93-94 °C dec (methanol); 1H
NMR (300 MHz, CDCl3) δ 7.33-7.25 (m, 5 H), 1.78 (s, 3 H),
1.40 (s, 3 H), 1.36 (s, 3 H), 1.35 (s, 3 H), 1.26 (s, 3 H); 13C NMR
(75 MHz, CDCl3) δ 143.99, 141.81, 128.15, 128.04, 127.18,
120.38, 40.64, 34.81, 26.43, 24.67, 24.16, 20.86, 20.81, 20.60,
1-D ic h lo r o m e t h y le n e -2,4,4,5,5-p e n t a m e t h y l-2-(1-
n a p h th yl)sp ir o[2.2]p en ta n e (3g): mp 155-156 °C (metha-
1
nol); H NMR (300 MHz, CDCl3) δ 8.17-8.14 (m, 1 H), 7.85-
7.82 (m, 1 H), 7.76-7.73 (m, 1 H), 7.50-7.37 (m, 4 H), 1.85 (s,
3 H), 1.52 (s, 3 H), 1.41 (s, 3 H), 1.11 (s, 3 H), 0.53 (s, 3 H); 13
C
NMR (100 MHz, CDCl3) δ 136.47, 135.41, 134.08, 132.46,
129.03, 127.90, 125.67, 125.56, 125.16, 125.15, 125.02, 104.22,
48.63, 36.11, 31.75, 31.29, 21.84, 21.24, 20.76, 20.01, 18.26;
IR (KBr) 3005, 2987, 2950, 2918, 2866 cm-1; UV (cyclohexane)
λmax 295 (log ꢀ ) 3.75), 284 (log ꢀ ) 3.91), 274 (log ꢀ ) 3.82),
224 nm (log ꢀ ) 4.78). Anal. Calcd for C21H22Cl2: C, 73.04; H,
6.42. Found: C, 73.00; H, 6.30.
20.53; IR (KBr) 3061, 2991, 2949, 2920, 2864, 1496, 1444 cm-1
;
UV (cyclohexane) λmax 211 nm (shoulder, log ꢀ ) 4.39). Anal.
Calcd for C17H20Br2: C, 53.15; H, 5.25. Found: C, 53.35; H,
5.21.
2,2-Dibr om o-3-(p-ch lor oph en yl)-2′,2′,3,3′,3′-pen tam eth yl-
1,1′-bicyclop r op ylid en e (8j): mp 69-75 °C dec (methanol);
1H NMR (300 MHz, CDCl3) δ 7.32-7.28 (m, 2 H), 7.22-7.19
(m, 2 H), 1.75 (s, 3 H), 1.38 (s, 3 H), 1.35 (s, 3 H), 1.34 (s, 3 H),
1.25 (s, 3 H); 13C NMR (75 MHz, CDCl3) δ 144.43, 140.31,
133.01, 129.54, 128.26, 120.03, 39.93, 34.12, 32.23, 24.79,
24.23, 20.83, 20.77, 20.57, 20.49; IR (KBr) 2987, 2952, 2918,
2866, 1488, 1375, 1088 cm-1; UV (cyclohexane) λmax 223 nm
(log ꢀ ) 4.36). Anal. Calcd for C17H19Br2Cl: C, 48.78; H, 4.58.
Found: C, 48.59; H, 4.48.
2,2-Dib r om o-2′,2′,3,3′,3′-p en t a m et h yl-3-(2-n a p h t h yl)-
1,1′-bicyclop r op ylid en e (8k ): mp 72-81 °C dec (methanol);
1H NMR (300 MHz, CDCl3) δ 7.85-7.66 (m, 4 H), 7.51-7.25
(m, 3 H), 1.86 (s, 3 H), 1.52 (s, 3 H), 1.39 (s, 3 H), 1.38 (s, 3 H),
1.31 (s, 3 H); 13C NMR (75 MHz, CDCl3) δ 143.99, 139.36,
132.97, 132.50, 127.75, 127.72, 127.59, 127.12, 126.12, 125.98,
125.84, 120.54, 40.81, 34.57, 26.40, 24.73, 24.21, 21.01, 20.84,
20.61, 20.57; IR (KBr) 3057, 2987, 2945, 2916, 2861, 1601,
1438, 1371 cm-1; UV (cyclohexane) λmax 276 (log ꢀ ) 3.87), 267
nm (log ꢀ ) 3.90). Anal. Calcd for C21H22Br2: C, 58.09; H, 5.11.
Found: C, 58.00; H, 5.00.
1-D i p h e n y lm e t h y li d e n e -4,4,5,5-t e t r a m e t h y l-2,2-
d ip h en ylsp ir o[2.2]p en ta n e (4): mp 176.5-177.5 °C (metha-
1
nol); H NMR (300 MHz, CDCl3) δ 7.41-7.00 (m, 20 H), 0.80
(s, 6 H), 0.75 (s, 6 H); 13C NMR (75 MHz, CDCl3) δ 143.57,
141.45, 140.81, 140.02, 138.91, 137.28, 131.20, 130.85, 128.95,
127.71, 127.64, 127.52, 127.21, 126.92, 126.28, 125.98, 125.70,
125.58, 43.77, 39.08, 30.43, 20.95, 20.47; IR (KBr) 3058, 3031,
2243, 1493 cm-1; UV (cyclohexane) λmax 302 (log ꢀ ) 3.89), 238
nm (log ꢀ ) 4.14). Anal. Calcd for C34H32: C, 92.68; H, 7.32.
Found: C, 92.78; H, 6.92.
(E )-1,1,2,2-Te t r a m e t h yl-4,4-d ip h e n yl-5-(p h e n ylt h io-
m eth ylen e)sp ir o[2.2]p en ta n e ((E)-5): mp 119-120 °C dec
1
(hexane); H NMR (300 MHz, CDCl3) δ 7.36-7.14 (m, 15 H),
6.62 (s, 1 H), 1.38 (s, 6 H), 0.98 (s, 6 H); 13C NMR (75 MHz,
CDCl3) δ 144.15, 140.90, 137.69, 128.81, 128.67, 127.80, 127.70,
125.82, 125.66, 105.44, 46.25, 40.53, 31.02, 21.77, 20.23; IR
(KBr) 3057, 3031, 2998, 2913, 2866, 1581, 1492, 1478, 1438,
1375, 1086, 1024 cm-1; UV (cyclohexane) λmax 279 (log ꢀ )
4.18), 258 nm (log ꢀ ) 4.13). Anal. Calcd for C28H28S: C, 84.80;
H, 7.12. Found: C, 84.40; H, 4.14.
2,2-Dich lor o-2′,2′,3,3′,3′-p en t a m et h yl-3-(1-n a p h t h yl)-
1,1′-bicyclop r op ylid en e (9g): mp 109-110 °C dec (metha-
nol); 1H NMR (300 MHz, CDCl3) δ 8.16-7.25 (m, 7 H), 1.83 (s,
1-Dibr om om eth ylen e-2,2-d ip h en ylcyclop r op a n e (7a ):
mp 92.5-93.5 °C (methanol); 1H NMR (300 MHz, CDCl3) δ
7.34-7.26 (m, 10 H), 2.16 (s, 2 H); 13C NMR (75 MHz, CDCl3)
δ 140.52, 136.55, 128.44, 127.89, 127.10, 76.04, 43.93, 28.07;
IR (KBr) 3057, 3026, 2979, 1957, 1748, 1592, 1494, 1448, 1013
3 H), 1.51 (s, 3 H), 1.35 (s, 3 H), 1.34 (s, 3 H), 1.32 (s, 3 H); 13
C
NMR (75 MHz, CDCl3) δ 142.71, 137.80, 133.95, 131.33,
128.56, 128.02, 126.16, 126.08, 125.71, 125.62, 125.20, 119.00,
63.44, 40.24, 24.48, 24.31, 24.03, 21.31, 21.05, 20.62, 20.57;
J . Org. Chem, Vol. 68, No. 20, 2003 7705

Maeda et al.
IR (KBr) 3065, 2989, 2926, 2866, 1507, 1448, 1371 cm-1; UV
Su p p or tin g In for m a tion Ava ila ble: Synthetic proce-
dure, spectral and analytical data of vinylidenecyclopropanes
1a -j, and X-ray reports and ORTEP drawings of 2a , 3g, 4,
(E)-5, and 9g. This material is available free of charge via the
Internet at http://pubs.acs.org.
(cyclohexane) λmax 296 (log ꢀ ) 3.81), 285 (log ꢀ ) 3.96), 275
(log ꢀ ) 3.85), 227 nm (log ꢀ ) 4.78). Anal. Calcd for C21H22
Cl2: C, 73.04; H, 6.42. Found: C, 73.13; H, 6.36.
-
Ack n ow led gm en t. This work was supported by a
Grant-in-Aid for Scientific Research from the Ministry
of Education, Science, Sports and Culture of J apan.
J O0301595
7706 J . Org. Chem., Vol. 68, No. 20, 2003