Chemistry Letters Vol.34, No.3 (2005)
381
Table 2. Vanadium-catalyzed isomerization of various cyclo-
propanemethanols
X
n-1O
O
V
R1
R1 OH
R2
•
5 mol% VOSO4 nH2O
10 mol% BHT
R1
R2
OH
R2
O
R1 OH
R2
PhCl (1 mL)
VOXn
O
HX
R1 O VXn-1
1
80 °C, 48 h
2
R1
VXn-1
0.2 mmol
R2
O
1
A
R2
Yield Major
/%a /Minorb
B
1
Entry
Substrate 1
Product 2
1
2
1a (R1 = R2 = Ph)
2a
2b
2c
2d
2d
2e
2e
2f
2g
2h
2i
91 N.A.c
90 N.A.
78 N.A.
48 trans only
79 trans only
67 94/6
70 93/7
66 83/17
73 83/17
73 80/20
17 N.A.
40 N.A.
1
1b (R1 = R2 = p-Tol)
3d 1c (R1 = R2 = 4-ClC6H4)
R1
OH
4
1d (R1 = Ph; R2 = H)
5e 1d (R1 = Ph; R2 = H)
1e (R1 = Ph; R2 = Me)
7e 1e
R2
2
6
Scheme 1.
8
9
1f (R1 = Ph; R2 = Et)
1g (R1 = Ph; R2 = Bu)
well as the reaction using other transition metals are in progress
and will be published in due course.
n
10d 1h (R1 = Ph; R2 = Bn)
n
11
12e 1i
1i (R1 = R2 = Bu)
References and Notes
1
2i
´
For examples, see: a) M. Julia, S. Julia, and R. Guegan, Bull.
aIsolated yield based on 1 employed. Determined by H NMR.
b
Soc. Chim. Fr., 1960, 1972. b) C. Santerri, Tetrahedron Lett.,
1979, 1165. c) J. P. McCormick and D. L. Barton, J. Org.
Chem., 45, 2566 (1980). d) K. Sakaguchi, M. Fujita, and Y.
Ohfune, Tetrahedron Lett., 39, 4313 (1998). e) J. Cossy, N.
Blanchard, and C. Meyer, Tetrahedron Lett., 43, 1801 (2002).
S. R. Wilson, A. E. Davey, and M. E. Guazzaroni, J. Org.
Chem., 57, 2007 (1992).
Y. Matsushima, H. Itoh, T. Nakayama, S. Horiuchi, T. Eguchi,
and K. Kakinuma, J. Chem. Soc., Perkin Trans. 1, 2002, 949.
a) H. Pauling, D. A. Andrews, and N. C. Hindley, Helv. Chim.
Acta, 59, 1233 (1976). b) P. Chabardes, E. Kuntz, and J.
Varagnat, Tetrahedron, 33, 1775 (1977). c) T. Hosogai, Y.
Fujita, Y. Ninagawa, and T. Nishida, Chem. Lett., 1982, 357.
a) S. Matsubara, T. Okazoe, K. Oshima, K. Takai, and H.
Nozaki, Bull. Chem. Soc. Jpn., 58, 844 (1985). b) J. Belgacem,
J. Kress, and J. A. Osborn, J. Am. Chem. Soc., 114, 1501
(1992).
cNot applicable. For 96 h. VO(acac)2 was used as a catalyst in
d
e
.
place of VOSO4 nH2O.
Table 3. Effect of radical inhibitor
2
3
4
•
5 mol% VOSO4 nH2O
10 mol% radical inhibitor
H
OH
Ph
OH
Ph
PhCl (1 mL)
H
1d
0.2 mmol
80 °C, 48 h
2d
Entry
Radical inhibitor
Yield/%a
1
2
3
4
5
none
BHT
33
48
55
56
51
5
Galvinoxyl
m-Dinitrobenzene
1,1-Diphenyl-2-picrylhydrazyl
6
7
T. Hosogai, Y. Fujita, Y. Ninagawa, and T. Nishida, Chem.
Lett., 1982, 357.
aIsolated yield based on 1d employed.
a) S. Bellemin-Laponnaz, H. Gisie, J. P. Le Ny, and J. A.
Osborn, Angew. Chem., Int. Ed. Engl., 36, 976 (1997). b) J.
Jacob, J. H. Espenson, J. H. Jensen, and M. S. Gordon,
Organometallics, 17, 1835 (1998). c) S. Bellemin-Laponnaz,
J. P. Le Ny, and J. A. Osborn, Tetrahedron Lett., 41, 1549
(2000). d) B. D. Sherry, A. T. Radosevich, and F. D. Toste,
J. Am. Chem. Soc., 125, 6076 (2003).
For examples, see: a) E. A. Braude, Q. Rev., Chem. Soc., 4, 404
(1950). b) S. Bellemin-Laponnaz and J. P. Le Ny, C. R. Chim.,
5, 217 (2002) and references cited therein.
For recent examples, see: a) S. Oi and B. M. Trost, J. Am.
Chem. Soc., 123, 1230 (2001). b) B. M. Trost, C. Jonasson,
and M. Wucher, J. Am. Chem. Soc., 123, 12736 (2001). c)
B. M. Trost and C. Jonasson, Angew. Chem., Int. Ed., 42,
2063 (2003).
(Entries 11 and 12).
In order to obtain some information about the reaction path-
way, the effect of a radical inhibitor such as BHT, galvinoxyl, m-
dinitrobenzene, and 1,1-diphenyl-2-picrylhydrazyl was investi-
gated. As summarized in Table 3, the reaction was not prevented
in the presence of any radical inhibitors, showing that this cata-
lytic reaction does not proceed via radical pathway.
Although the details are not yet clear, we propose that the
reaction may proceed via the pathway shown in Scheme 1 in
analogy with the so-far known transposition of various alcohols:
1) an oxo metal complex reacts with cyclopropanemethanol to
afford an oxo metal cyclopropanemethanolate (A), 2) the
[3,3]sigmatropic rearrangement of this alcoholate accompanied
by the C–C bond cleavage occurs to give an oxo metal homoal-
lylic alcoholate (B) which then reacts with another cyclopro-
panemethanol to give the product homoallylic alcohol (2) and
the oxo metal methanolate A.
8
9
10 a) Y. Maeda, N. Kakiuchi, S. Matsumura, T. Nishimura, and S.
Uemura, Tetrahedron Lett., 42, 8877 (2001). b) Y. Maeda, N.
Kakiuchi, S. Matsumura, T. Nishimura, T. Kawamura, and S.
Uemura, J. Org. Chem., 67, 6718 (2002). c) Y. Maeda, M.
Koyabu, T. Nishimura, and S. Uemura, J. Org. Chem., 69,
7688 (2004).
In summary, we found a first transition metal complex-cat-
alyzed isomerization of cyclopropanemethanols to the corre-
sponding homoallylic alcohols. Further mechanistic studies as
Published on the web (Advance View) February 12, 2005; DOI 10.1246/cl.2005.380