A simple and efficient conversion of tertiary cyclopropanols to 2-substituted allyl halides

Article abstract of DOI:10.1055/s-2002-20461

Readily available sulphonates of tertiary cyclopropanols are converted into 2-substituted allyl bromides in high yields under the action of magnesium bromide in diethyl ether. Magnesium chloride, aluminium chloride and titanium tetrachloride also induce effectively the transformation of cyclopropyl sulphonates into the corresponding allyl chlorides.

Full text of DOI:10.1055/s-2002-20461

LETTER
443
A Simple and Efficient Conversion of Tertiary Cyclopropanols to 2-Substitu-
ted Allyl Halides
Conversion of
Ter
u
tiary
C
yclopropanolsii Yu. Kozyrkov, Oleg G. Kulinkovich*
Department of Organic Chemistry, Belarusian State University, 4, Skoriny av., Minsk, 220050, Belarus
Fax +375(17)2264998; E-mail: kulinkovich@bsu.by
Received 18 December 2001
the presence of titanium(IV) isopropoxide,1 and was
Abstract: Readily available sulphonates of tertiary cyclopropanols
are converted into 2-substituted allyl bromides in high yields under
the action of magnesium bromide in diethyl ether. Magnesium chlo-
ride, aluminium chloride and titanium tetrachloride also induce ef-
smoothly converted into cyclopropyl sulphonates 2a,b by
a standard procedure (Scheme 1).12 Quite surprisingly, we
have found that, in contrast to the solvolysis of cyclopro-
fectively the transformation of cyclopropyl sulphonates into the pylsulphonates,7,10 which proceeded slowly and not un-
corresponding allyl chlorides.
ambiguously, the interaction of cyclopropyl mesylate 2a
with magnesium bromide13 in diethyl ether at room tem-
Key words: cyclopropanols, sulphonic esters, ring cleavage, allyl
halides, magnesium halides
perature led to allyl bromide 3 in an excellent yield14 (see
Table, entry 1). The reaction of tosylate 2b with magne-
sium bromide proceeded at a lower rate, however, the
yield of allyl bromide 3 remained high enough (entry 2).
Tertiary cyclopropanols are readily available by the cy-
clopropanation of esters,1,2 desilylation of cyclopropanol
silyl ethers,3,4 alkylation of cyclopropanone hemiace-
tals,5,6 and using some other approaches.7 Their synthetic
applications are based mainly on the ring opening reac-
tions, when one of the bonds adjacent to carbinol carbon
atom (C1-C2 or C1-C3 bonds in cyclopropane ring) un-
dergoes cleavage. These transformations are usually initi-
ated with electrophilic, basic or oxidizing reagents4,6–8 and
strongly facilitated by electron-donating oxygen atom. In
contrast, solvolysis of cyclopropyl p-toluenesulphonates
and triflates is usually accompanied by the C2-C3 cyclo-
propane ring cleavage, and these reactions were intensive-
ly studied stereochemically and kinetically with a
mechanistic interest to the cationic cyclopropyl-allyl rear-
rangement.7,9–11 Nevertheless, the preparative value of
this transformation was not demonstrated clearly. We now
report a simple and highly efficient procedure for the con-
version of cyclopropyl sulphonates into 2-substituted allyl
halides, which are widely used in organic synthesis, and
believe that this finding will contribute to reducing the
disbalance in synthetic application of C1-C2 versus C2-
C3 modes of the cyclopropanol ring opening reactions.
The 1-heptyl (entry 3), 1-phenylmethyl (entry 5), 1-ha-
loalkyl (entries 7–9, 11) and 1-phenyl substituted (entry
12) cyclopropyl sulphonates also gave in this transforma-
tion high yields of the corresponding 2-substituted allyl
halides. Compounds containing two cyclopropyl sulpho-
nate groups were transformed into the corresponding
dienic bromides without any complications (entries 13,
14). Magnesium chloride, as well as aluminium and tita-
nium(IV) chlorides, were also effective in inducing the
conversion of cyclopropyl sulphonates into allyl halides
(entries 4, 6, 10).
cis-1,2-Disubstituted cyclopropanols (entries 15–19)
were prepared by inter-15 or intramolecular16 cyclopropa-
nation of the corresponding carboxylic esters with alkyl-
magnesium halides in the presence of titanium(IV)
isopropoxide. In the reaction with magnesium bromide,
the respective methanesulphonic esters gave allyl halides
as a mixture of stereo- and regioisomers. Compounds with
the most substituted double bond were formed preferably
in these cases (entries 15–19). The transformation was
also successfully applied for the preparation of allyl bro-
mide containing a protected acetal group in the side chain
(entry 20).
1-Hexyl-1-cyclopropanol 1 was obtained by the treatment
of methyl heptanoate with ethyl magnesium bromide in
Scheme 1 R = Me (a), p-CH3C6H4 (b).
Synlett 2002, No. 3, 04 03 2002. Article Identifier:
1437-2096,E;2002,0,03,0443,0446,ftx,en;G34301ST.pdf.
© Georg Thieme Verlag Stuttgart · New York
ISSN 0936-5214

444
Y. Yu. Kozyrkov, O. G. Kulinkovich
LETTER
Table The Reaction of Cyclopropyl Sulphonates with Metal Halides in Diethyl Ether
Entry
1
Cyclopropyl Sulphonatea
Metal Halide Time (h)
Productb,c
Isolated Yield, [%]
MgBr2
1
95
2a
2b
3
3
2
MgBr2
12
80
3
4
MgBr2
AlCl3
2
90
80
48
5
6
7
MgBr2
48
24
24
68
72
70
d
MgCl2
MgBr2
8
9
MgBr2
MgBr2
TiCl4
24
6
81
71
79
10
24
11
MgBr2
72
79
12
13
14
15
MgBr2
MgBr2
MgBr2
MgBr2
0.5
80
88
92
77
3g
5g
2
65e:35
16
17
TiCl4
4
1
62
75
60f:40
75g:25
MgBr2
18
19
MgBr2
MgBr2
1
1
74
80
100h
90:10
Synlett 2002, No. 3, 443–446 ISSN 0936-5214 © Thieme Stuttgart · New York

LETTER
Conversion of Tertiary Cyclopropanols
445
Table The Reaction of Cyclopropyl Sulphonates with Metal Halides in Diethyl Ether (continued)
Entry
20
Cyclopropyl Sulphonatea
Metal Halide Time (h)
MgBr2
Productb,c
Isolated Yield, [%]
65
8
70i:30
a Selected data of substituted methanesulfonates see ref.17
b Selected data of allyl halides see ref.18
c E/Z ratio was determined by 1H NMR spectra.
d In dichloromethane.
e E/Z = 90:10.
f E/Z = 70:30.
g E/Z = 85:15.
h E/Z = 85:15.
i E/Z ratio was not determined.
(3) (a) Denis, J. M.; Conia, J. M. Tetrahedron Lett. 1972, 4593.
(b) Le Goaller, R.; Pierre, J.-L. Bull. Soc. Chim. Fr. 1973,
1531. (c) Rubotton, G. M.; Lopes, M. I. J. Org. Chem. 1973,
38, 2097.
(4) (a) Conia, J. M. Pure Appl. Chem. 1975, 43, 317. (b) Ryu,
I.; Murai, S. In Houben-Weyl, 4th ed., Vol. E 17; de Meijere,
A., Ed.; Thieme: Stuttgart, 1996, 1985. (c) Kuwajima, I.;
Nakamura, E. Top. Curr. Chem. 1990, 155, 3.
(5) (a) Wasserman, H. H.; Clagett, D. C. J. Am. Chem. Soc.
1966, 88, 5368. (b) Wasserman, H. H.; Cochoy, R. E.;
Baird, M. S. J. Am. Chem. Soc. 1969, 91, 2375.
(6) (a) Wasserman, H. H.; Clark, G. M.; Turley, P. C. Top. Curr.
Chem. 1974, 47, 73. (b) Turro, N. J. Cyclopropanones 1969,
25. (c) Salaün, J. Chem. Rev. 1983, 83, 619. (d) Salaün, J.
Top. Curr. Chem. 1988, 144, 1.
Mechanistically it seems clear, that this reaction includes
a Lewis acid assisted heterolytic cleavage of carbon-oxy-
gen bond in cyclopropyl sulphonates which induces a cat-
ionic cyclopropyl-allyl rearrangement7,10 (Scheme 2). The
fact that the reaction did not proceed in tetrahydrofuran
solution suggests that the Lewis acid should not be exces-
sively solvated. Indeed, cyclopropyl sulphonates reacted
faster with magnesium, titanium and aluminium halides in
poorly solvating dichloromethane, but formation of allyl
halides was sometimes accompanied by resin-like side
products.
(7) Gibson, D. H.; De Puy, C. H. Chem. Rev. 1974, 74, 605.
(8) (a) Werstiuk, N. H. Tetrahedron 1983, 39, 205.
(b) Grimmis, M. T.; Nantermet, P. G. Org. Prep. Proced. Int.
1993, 25, 43. (c) Kulinkovich, O. G. Pol. J. Chem. 1997, 71,
849.
(9) (a) Roberts, J. D.; Chambers, V. C. J. Am. Chem. Soc. 1951,
73, 5034. (b) De Puy, C. H.; Schnack, L. G.; Hausser, J. W.
J. Am. Chem. Soc. 1966, 88, 3343.
(10) For reviews see: (a) Jendralla, H. In Houben-Weyl, 4th ed.,
Vol. E 19; de Meijere, A., Ed.; Thieme: Stuttgart, 1996,
2313. (b) Schollkopf, U. Angew. Chem., Int. Ed. Engl. 1968,
7, 588. (c) Friedrich, E. C. In The Chemistry of the
Cyclopropyl Group; Rappoport, Z., Ed.; Wiley: London,
1987, Chap. 11, 633. (d) Salaün, J. In The Chemistry of the
Cyclopropyl Group; Rappoport, Z., Ed.; Wiley: London,
1987, Chap. 13, 809. (e) Salaün, J. J. Org. Chem. 1976, 41,
1237; and references cited therein.
Scheme 2 R, R1 = alkyl, aryl; R + R1 = –(CH2)3–; R2 = Me,
In summary, a highly efficient method for conversion of
readily available tertiary cyclopropanols to 2-substituted
allyl halides have been elaborated.
(11) Momose and co-workers have recently found that treatment
of tertiary cyclopropyl silyl ethers with diethylaminosulfur
trifluoride give allylic fluorides in moderate to high yield:
Kirihara, M.; Kambayashi, T.; Momose, T. Chem. Commun.
1996, 1103.
Acknowledgement
This work was carried out with support of the COPERNICUS pro-
gramme.
(12) Ollivier, J.; Dorizon, P.; Piras, P. P.; de Meijere, A.; Salaün,
J. Inorg. Chim. Acta. 1994, 222, 37.
References
(13) We have obtained this finding quite accidentally. A search in
the literature revealed that magnesium halides have been
earlier proposed by Gore and co-workers as an efficient
reagent for nucleophilic displacement of p-tosyloxy or
mesyloxy groups by halogen atoms: Place, P.;
(1) (a) Kulinkovich, O. G.; Sviridov, S. V.; Vasilevskii, D. A.;
Pritytskaya, T. S. Zh. Org. Khim. 1989, 25, 2244.
(b) Kulinkovich, O. G.; Sviridov, S. V.; Vasilevskii, D. A.
Synthesis 1991, 234.
(2) (a) Kulinkovich, O. G.; de Meijere, A. Chem. Rev. 2000,
100, 2789. (b) Sato, F.; Urabe, H.; Okamoto, S. Chem. Rev.
2000, 100, 2835.
Roumestanant, M.-L.; Gore, J. Bull. Soc. Chim. Fr. 1976,
169.
Synlett 2002, No. 3, 443–446 ISSN 0936-5214 © Thieme Stuttgart · New York

446
Y. Yu. Kozyrkov, O. G. Kulinkovich
LETTER
(14) Typical Procedure:
(16) (a) Kasatkin, A.; Sato, F. Tetrahedron Lett. 1995, 36, 6079.
(b) Lee, J.; Kim, H.; Cha, K. J. Am. Chem. Soc. 1996, 118,
4198. (c) Lee, J.; Kim, H.; Bae, J. G.; Cha, K. J. Org Chem.
1996, 61, 4878. (d) Lee, J.; Kang, C. H.; Kim, H.; Cha, K. J.
Am. Chem. Soc. 1996, 118, 291.
A solution of 1-hexylcyclopropyl methanesulfonate 2a 7.65
g (35 mmol) in 10 mL Et2O was added slowly into MgBr2
(52 mmol) solution (prepared from 1.26 g magnesium
turnings and 4.5 mL 1,2-dibromoethane in 30 mL Et2O) at
r.t. When the reaction was completed (control by TLC),
water was added to the mixture until precipitate was
dissolved. Water layer was extracted with Et2O, washed with
5% NaCl solution and dried over Na2SO4. After evaporation
of the solvent, the resulting crude product was purified by
column chromatography, using petroleum ether eluent and
silica gel (Merck 70-230), yielding 6.82 g (95%) of pure
allyl halide 3.
(17) Entry 11: 1H NMR (200 MHz, CDCl3) = 0.60–0.74 (m, 1
H), 0.80–0.92 (m, 1 H), 1.06–1.22 (m, 2 H), 1.74 (d, J = 6.5
Hz, 3 H), 2.09 (dd, J1 = 15 Hz, J2 = 8 Hz, 1 H), 2.45 (s, 3 H),
2.49 (dd, J1 = 15 Hz, J2 = 6 Hz, 1 H), 4.28–4.50 (m, 1 H),
7.35 (d, J = 8 Hz, 2 H), 7.77 (d, J = 8 Hz, 2 H). Entry 19: 1H
NMR (200 MHz, CDCl3) = 0.92 (t, J = 6 Hz, 1 H), 1.04–
1.40 (m, 2 H), 1.58 (dd, J1 = 12 Hz, J2 = 8 Hz, 1 H), 1.66–
2.06 (m, 3 H), 2.10–2.44 (m, 2 H), 3.02 (s, 3 H).
(15) (a) Kulinkovich, O. G.; Sviridov, S. V.; Vasilevski, D. A.;
Savchenko, A. I.; Pritytskaya, T. S. Zh. Org. Khim. 1991, 27,
294. (b) Epstein, O. L.; Savchenko, A. I.; Kulinkovich, O. G.
Tetrahedron Letters 1999, 40, 5935.
(18) Entry 11: 1H NMR (200 MHz, CDCl3): = 1.76 (d, J = 6.5
Hz, 3 H), 2.61–2.89 (m, 2 H), 4.01 (s, 2 H), 4.17–4.28 (m, 1
H), 5.08 (d, J = 1 Hz, 1 H), 5.32 (s, 1 H). nD20 = 1.5235.
Entry 19: 1H NMR (200 MHz, CDCl3): = 1.86–2.06 (m, 2
H), 2.28–2.50 (m, 4 H), 4.08 (s, 1.8 H), 4.88–4.95 (m, 0.1 H),
5.07 (s, 0.1 H), 5.30 (s, 0.1 H), 5.78 (s, 0.9 H).
Synlett 2002, No. 3, 443–446 ISSN 0936-5214 © Thieme Stuttgart · New York