Novel and efficient method for the allylation of carbonyl compounds and imines using triallylaluminum

Article abstract of DOI:10.1021/jo052385f

This is the first report of the use of triallylaluminum as a reagent for the allylation of carbonyl compounds and imines. The allylation of ketimines without additional metal catalyst is known so far only in the case of the Grignard reagent. Triallylaluminum is a useful alternative to provide the homoallylic amines in excellent yield upon addition to aldimines and ketimines. The significant reactivity of this reagent was confirmed by its reaction with a sterically rigid ketone such as adamantanone to provide 1-adamantyl-3-buten-1-ol in 98% yield. The chemoselectivity of triallyl-aluminum was demonstrated by using different ketoesters. It is noteworthy that triallylaluminum is prepared from allyl bromide and aluminum metal, and not from a Grignard reagent, and that the procedure is operationally simple, leading to good to excellent product yields.

Full text of DOI:10.1021/jo052385f

developed for these transformations. The Grignard-type carbonyl
addition of allyl halides has been developed in which organo-
metallics derived from a number of metallic elements such as
manganese,8 zinc,9 tin,10 antimony,11 magnesium,12 cerium,13
and bismuth are used.14 Allylation reactions with organometallic
reagents has largely been used in conjunction with aldehydes,
but rarely for ketones, because of the difference in reactivity
between these carbonyl groups. Wada and co-workers14 reported
on the allylation of aldehydes using allyl bromide and metallic
bismuth [Bi(0)] or bismuth(III) chloride in the presence of
metallic species such as Zn(0), Fe(0), and Al(0). However, the
use of bismuth(III) chloride was not successful in the absence
of Al(0) and Al(0) alone did not lead to the production of the
desired products. Mukaiyama et al.15 reported on the efficient
allylation of aldehydes using allyldiethylaluminum, in which
the organoaluminum was produced via the reaction of diethyl-
aluminum chloride with allylmagnesium chloride. Albeit, al-
dehydes responded well with this reagent and ketones were
unreactive. It is always important to examine the use of various
elements in organic synthesis from the standpoint of their use
in the future. Reports on the allylation of carbonyl compounds
using organoaluminum reagents are relatively rare.16 Thus, it
would be desirable to develop an efficient allylation method
for a wide variety of substrates with organoaluminum com-
pounds in a Grignard-type addition, because aluminum is an
inexpensive and convenient alternative to conventionally used
metals, such as magnesium and zinc. In this paper, we wish to
report on a convenient and efficient procedure for the allylation
of aldehydes, ketones, and imines using triallylalumium (2) in
excellent to good yields. It is noteworthy that the preparation
of the triallylalumium reagent may be carried out conveniently
using allyl bromide and aluminum metal,17,18 a significant
improvement over earlier methods which relied upon the
reaction of a dialkylaluminum halide with allylmagnesium
chloride.19
Novel and Efficient Method for the Allylation of
Carbonyl Compounds and Imines Using
Triallylaluminum
Kao-Hsien Shen and Ching-Fa Yao*
Department of Chemistry, National Taiwan Normal UniVersity
88, Sec. 4, Tingchow Road, Taipei, Taiwan 116, R.O.C.
cheyaocf@scc.ntnu.edu.tw
ReceiVed NoVember 18, 2005
This is the first report of the use of triallylaluminum as a
reagent for the allylation of carbonyl compounds and imines.
The allylation of ketimines without additional metal catalyst
is known so far only in the case of the Grignard reagent.
Triallylaluminum is a useful alternative to provide the
homoallylic amines in excellent yield upon addition to
aldimines and ketimines. The significant reactivity of this
reagent was confirmed by its reaction with a sterically rigid
ketone such as adamantanone to provide 1-adamantyl-3-
buten-1-ol in 98% yield. The chemoselectivity of triallyl-
aluminum was demonstrated by using different ketoesters.
It is noteworthy that triallylaluminum is prepared from allyl
bromide and aluminum metal, and not from a Grignard
reagent, and that the procedure is operationally simple,
leading to good to excellent product yields.
(6) (a) Davis, A. P.; Jaspars, M. Angew. Chem., Int. Ed. Engl. 1992, 31,
470. (b) Fleming, I.; Dunogues, J.; Smithers, R. Org. React. 1989, 37, 57.
(c) Hosomi, A.; Shirahata, A.; Sakurai, H. Tetrahedron Lett. 1978, 19, 3043.
(7) (a) Yamamoto, Y.; Yatagai, H.; Ishihara, Y.; Maeda, N.; Maruyama,
K. Tetrahedron 1984, 40, 2239. (b) Naruta, Y.; Ushida, S.; Maruyama, K.
Chem. Lett. 1979, 919.
(8) Hiyama, T.; Sawahata, M.; Obayashi, M. Chem. Lett. 1983, 1237.
(9) (a) Christian, P.; Luche, J. L. J. Org. Chem. 1985, 50, 910. (b) Petrier,
C.; Einhorn, J.; Luche, J. L. Tetrahedron Lett. 1985, 26, 1449.
(10) (a) Mukaiyama, T.; Harada, T. Chem Lett. 1981, 1527. (b) Nokami,
J.; Otera, J.; Sudo, T.; Okawara, R. Organometallics 1983, 2, 191. (c)
Uneyama, K.; Matsuda, H.; Torii, S. Tetrahedron Lett. 1984, 25, 6017.
(11) Butsugan, Y.; Ito, H.; Asaki, S. Tetrahedron Lett. 1987, 28, 3707.
(12) (a) Blomberg, L.; Hartog, F. A. Synthesis 1977, 18. (b) Yamamoto,
Y.; Komatsu, T.; Maruyama, K. J. Chem. Soc., Chem. Commun. 1985, 814.
(13) (a) Imamoto, T.; Hatanaka, Y.; Tawarayama, Y.; Yokoyama, M.
Tetrahedron Lett. 1981, 22, 4987. (b) Imamoto, T.; Kusumoto, T.;
Tawarayama, Y.; Sugiura, Y.; Mita, T.; Hatanaka, Y.; Yokayama, M. J.
Org. Chem. 1984, 26, 4771.
The allylation of carbonyl derivatives and imines is of great
interest in carbon-carbon bond-forming reactions as a result
of the versatility of homoallylic alcohols and amines as synthetic
intermediates.1 Homoallylic alcohols are particularly valuable
intermediates that have been used as building blocks of
numerous macrolides and ionophore antibiotics.2 Among the
methods reported for the allylation of these compounds, the most
common is a Barbier-type allylation in which allyl halide along
with different metal sources are used,3 and by the addition of
an allylic Grignard-type reagent.4 Over the past few decades, a
number of organometallic reagents such as Grignard reagents,
organolithiums,5 organosilanes,6 and organostannanes7 have been
(1) (a) Yamamoto, Y.; Asao, N. Chem. ReV. 1993, 93, 2207. (b) Hoffman,
R. W. Angew. Chem., Int. Ed. Engl. 1982, 21, 555. (c) Marshall, J. A.
Chemtracts 1992, 5, 75.
(2) Masamune, S.; Bates, G. S.; Corcoran, J. W. Angew. Chem., Int. Ed.
Engl. 1977, 16, 585.
(14) (a) Wada, M.; Akiba, K.-Y. Tetrahedron Lett. 1985, 26, 4211. (b)
Wada, M.; Ohki, H.; Akiba, K.-Y. Tetrahedron Lett. 1986, 27, 4771. (c)
Wada, M.; Ohki, H.; Akiba, K.-Y. Bull. Chem. Soc. Jpn. 1990, 63, 1738.
(15) Mukaiyama, T.; Minowa, N.; Oriyama, T.; Narasaka, K. Chem. Lett.
1986, 97.
(3) For a survey of the Barbier reaction: Blomberg, C.; Hartog, F. A.
Synthesis 1977, 18.
(4) (a) Kharasch, M. S.; Fuchs, C. F. J. Org. Chem. 1944, 9, 359. (b)
Gilman, H.; McGlumphy, J. H. Bull. Soc. Chem. Fr. 1928, 43, 1322.
(5) (a) Seyferth, D.; Murphy, G. J.; Mauze, B. J. Am. Chem. Soc. 1977,
99, 5317. (b) Seyferth, D.; Weiner, M. A. J. Org. Chem. 1961, 26, 4797.
(16) Saito, S. In Main Group Metals in Organic Symthesis; Yamamoto,
H., OShima, K., Eds.; Wiley-VCH: Weinheim, Germany, 2004; Vol. 1,
pp 189-300.
(17) The triallylaluminum (2) was prepared according to the procedures
in the following: Komiya, S. Synthesis of Organometallic Compounds; John
Wiley & Sons: New York, 1997.
10.1021/jo052385f CCC: $33.50 © 2006 American Chemical Society
Published on Web 04/07/2006
3980
J. Org. Chem. 2006, 71, 3980-3983

TABLE 1. Effect of the Loading of Triallylaluminum in a
Reaction with Benzaldehyde
explained on the basis of their reactivity. To further examine
the versatility of this reagent, a range of carbonyl compounds
were then allylated under the optimized conditions, and the
results are summarized in Table 2.
Homoallylic alcohols were obtained in good to excellent
yields, not only with aldehydes but also with ketones, by slight
variations in the temperature. Both aromatic as well as aliphatic
substrates were converted smoothly to the corresponding
homoallylic alcohols in excellent yields. The results clearly show
that a substituent on the phenyl ring, whether electron-donating
or electron-withdrawing, had almost no influence on the reac-
tions. Further, the position of the substituent on the phenyl ring
almost does not affect product yield. For example, 4-chloro-
benzaldehyde and 4-methylbenzaldehyde afforded allylated
products in excellent yields. Similarly, the use of the corre-
sponding 2-substituted benzaldehydes also resulted in excellent
yields. In addition to other aldehydes, the bulkier 1-formyl
naphthalene also gave an excellent yield while conducting the
reaction by method B (-78 °C to 0 °C). On the other hand,
almost all ketones furnished homoallylic alcohols in excellent
yields at 20 °C. Sterically hindered ketones such as di-tert-butyl
ketone, 2-acetyl naphthalene, and benzophenone also afforded
excellent yields of product. Moreover, this reagent has been
employed with cyclic ketones such as cyclohexanone to give
the corresponding allylated products in almost quantitative
yields. The significant reactivity of this reagent was confirmed
in a reaction with a sterically rigid ketone, adamantanone. The
higher yield obtained with adamantanone demonstrates the
versatility of triallylaluminum as an efficient allylating agent
for a wide range of substrates. It is noteworthy that this is the
first and foremost example on the allylation of 2-adamantanone
with an organometallic reagent and that these types of sterically
rigid structures are helpful in studying face selectivity.20 To the
best of our knowledge, this constitutes an original report of a
Grignard-type addition on the allylation of ketones using
triallylaluminum.
The allylation of aldimines and ketimines provides a useful
synthetic pathway to homoallylic amines, which are very useful
intermediates in the syntheses of natural products.21 Studies have
also revealed that secondary and tertiary homoallylic amines
such as zimelidine, norzimelidine, and so on, were neuronal
norepinephrine and serotinine-uptake inhibitors of biological
interest.22 Homoallylic amines are generally prepared either by
the addition of an organometallic reagent to an imine23 or by
the nucleophilic addition of allylmetal reagents in the presence
of Lewis acids.24 A variety of catalysts have been developed
for the preparation of homoallylic amines using three-component
coupling reactions25 including lanthanide triflates26 and bismuth
triflate.27 However, the high cost, substrate specificity, and
0 °Ca
-30-0 °Cb
3ad (%)
-78-0 °Cc
3ad (%)
entry
2 (mmol)
3ad (%)
1
2
3
4
0.20
0.30
0.40
0.50
25
56
86
86
27
61
87
95
28
75
96
98
a All reactions were carried out with benzaldehyde (1.0 mmol in 3 mL
dry ether) and triallylaluminum at 0 °C under nitrogen for 30 min. b All
reactions were carried out with benzaldehyde (1.0 mmol in 3 mL dry ether)
and triallylaluminum at -30 °C first, and the temperature was then gradually
increased to 0 °C under nitrogen for 40 min. c All reactions were carried
out with benzaldehyde (1.0 mmol in 3 mL dry ether) and triallylalumium
at -78 °C first, and the temperature was then gradually increased to 0 °C
under nitrogen for 90 min. d Isolated yields.
Preliminary endeavors focused on product yield optimization.
Initially, a reaction was carried out using benzaldehyde and
triallylaluminum (0.2 mmol) in dry ether at 0 °C, which resulted
in the production of the homoallylic alcohol in 25% yield after
30 min. With this information in hand, we then investigated
the effect of temperature as well as the amount of triallylalu-
minum in an attempt to increase the product yield. A gradual
increase in the amount of triallylaluminum used improved the
yield considerably, and the results are tabulated (Table 1).
From Table 1, it is evident that 0.4 mmol of triallylaluminum
is required to obtain the maximum yield. When the reaction
was carried out at 0 °C, the product was formed in 86% yield,
whereas adding triallylaluminum at -30 °C and then gradually
increasing the temperature to 0 °C resulted in only a slight
improvement in product yield. However, the maximum product
yield (96%) was obtained by adding triallylaluminum at -78
°C, followed by a gradual increase in the temperature to 0 °C.
The increased yield at lower temperatures can be attributed to
the decreased reactivity of the aldehyde, which in turn facilitates
the formation of a polymer-free product. Using additional
equivalents (0.5 mmol) of triallylaluminum at 0 °C had no effect
on the yield; on the other hand, only a small improvement was
observed in product yield when the reaction was conducted at
lower temperatures. With this encouraging result in hand, we
further investigated the reaction of ketones. The latter reaction
required a larger amount of triallylaluminum to proceed
smoothly, but products were produced in excellent yield. As
expected, an increase in the amount of triallylaluminum used
led to an increase in product yields, even in the case of ketones.
These results suggest that a minimum of 0.4 mmol of
triallylaluminum is needed in the allylation of aldehydes and
0.7 mmol is needed in the case of ketones to obtain the
maximum product yield. The difference in the amount of
triallylaluminum required to initiate these reactions may be
(20) (a) Carey, F. A.; Sundberg, R. J. Part A: Structure and Mechanisms.
AdVanced Organic Chemistry, 4th ed.; Kluwer Academic/Plenum Publish-
ers: New York, 2000; pp 171-176. (b) Kaselj, M.; Chung, W.-S.; le Noble,
W. J. Chem. ReV. 1999, 99, 1387. (c) Gung, B. W. Chem. ReV. 1999, 99,
1377.
(21) Ovaa, H.; Stragies, R.; van der Marel, G. A.; van Boom, J. H.;
Blechert, S. Chem. Commun. 2000, 1501.
(18) The concentration of triallylaluminum (2) was determined by the
following methods: (a) Gilman, H.; Haubein, A. H. J. Am. Chem. Soc.
1944, 66, 1516. (b) Bergreiter, D. E.; Pendergrass, E. J. Org. Chem. 1981,
46, 219. (c) Browen, M. E.; Aavula, B. R.; Mash, E. A. J. Org. Chem.
2002, 67, 9087.
(19) (a) Paley, R. S.; Snow, S. R. Tetrahedron Lett. 1990, 31, 5853. (b)
Rainier, J. D.; Cox, J. M. Org. Lett. 2000, 2, 2707. (c) Allwein, S. P.; Cox,
J. M.; Howard, B. E.; Johnson, H. W. B.; Rainier, J. D. Tetrahedron 2002,
58, 1997.
(22) Hogberg, S.; Ross, B.; Storm, P.; Grunewald, G. L.; Creese, M.
W.; Bunce, J. D. J. Med. Chem. 1988, 31, 913.
(23) (a) Bloch, R. Chem. ReV. 1998, 98, 1407. (b) Chan, T. H.; Lu, W.
Tetrahedron Lett. 1998, 39, 8605.
(24) (a) Keck, G. E.; Enholm, E. J. J. Org. Chem. 1985, 50, 146. (b)
Itsuno, S.; Watanabe, K.; Ito, A.; El-hehawy, A.; Sarhan, A. A. Angew.
Chem., Int. Ed. Engl. 1997, 36, 109. (c) Ajiyama, T.; Iwai, J. Synlett 1998,
273. (d) Nakamura, H.; Iwama, H.; Yamamoto, Y. J. Am. Chem. Soc. 1996,
118, 6641.
J. Org. Chem, Vol. 71, No. 10, 2006 3981

TABLE 2. Reaction of Aldehydes and Ketones with Triallylaluminum 2 To Generate Homoallylic Alcohols 3
Method Aa,b
Method Bb,c
Method Cb,d
entry
1
R1
R2
3
(%)
(%)
(%)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
1a
1b
1c
1d
1e
1f
1g
1h
1i
1j
1k
1l
1m
1n
1o
1p
1q
1r
1s
Ph
H
H
H
H
H
H
H
H
H
H
H
H
CH3
CH3
CH3
CH3
CH3
CH3
CH3
3a
3b
3c
3d
3e
3f
3g
3h
3i
3j
3k
3l
3m
3n
3o
3p
3q
3r
3s
86
83
83
84
79
99
82
81
83
99
84
70
96
98
97
96
96
95
50
97
83
98
82
90
4-ClC6H4
4-MeC6H4
2-ClC6H4
2-MeC6H4
PhCH2CH2
2-thienyl
1-naphthyl
3-pentyl
cyclohexyl
Bu
t-Bu
Ph
98
98
95
97
96
96
98
98
89
89
94
90
98
4-ClC6H4
4-MeC6H4
2-ClC6H4
2-MeC6H4
2-naphthyl
PhCH2CH2
-(CH2)5-
-(CH2)4-
Et
1t
3t
1u
1v
1w
1x
1y
3u
3v
3w
3x
3y
Et
Ph
t-Bu
Ph
t-Bu
2-adamantanone
a Method A: all reactions were carried out with aldehyde (1.0 mmol in 3 mL dry ether) and triallylaluminum (0.4 mmol, 0.5 M × 0.8 mL) at 0 °C under
nitrogen for 30 min. b Isolated yields. c Method B: all reactions were carried out with aldehyde (1.0 mmol in 3 mL dry ether) and triallylaluminum (0.4
mmol, 0.5 M × 0.8 mL) at -78 °C first and then increased to 0 °C gradually under nitrogen for 90 min. d Method C: all reactions were carried out with
ketone (1.0 mmol in 3 mL dry ether) and triallylaluminum (0.7 mmol, 0.5 M × 1.4 mL) at 20 °C under nitrogen for 30 min.
sensitivity of these reagents limit these processes. The allylation
of ketimines without the need for a metal catalyst is not known
so far, except for the case of a Grignard reagent.28 Thus, under
the optimized conditions developed for the carbonyl compounds,
we initiated a study of allylation reactions of aldimines as well
as ketimines. To evaluate the efficiency of this reagent and to
further explore the scope of the reagent, a series of substituted
aldimines and ketimines were subjected to the allylation reaction
using triallylaluminum. Both aldimines and ketimines reacted
with equal efficiency to afford products smoothly and in
excellent yield (Table 3).
Although there was no significant difference in product yields,
the reaction temperatures required varied depending on the
reactivity pattern of the substrates. In the case of aldimines, the
substituent on the nitrogen atom was a key determinant of
reactivity. For example, the reaction of N-methylimine derived
from benzaldehyde required 0 °C, the N-naphthylimine derived
from the same compound required 20 °C, and the other
aldimines reacted at room temperature to afford the maximum
product yields. On the other hand, ketimines react with
TABLE 3. Reaction of Aldimines and Ketimines with
Triallylaluminum 2 To Generate Homoallylic Amines 5
0 °Ca,b 50 °Cb,c
(%)
entry
4
R1
R2
R3
5
(%)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
4a Ph
H
Ph
Ph
Ph
Ph
Ph
Bn
Bn
5a
5b
5c
5d
5e
5f
98
98
98
95
98
98
98
96d
98
4b 4-MeOC6H4
4c 4-ClC6H4
4d 1-naphthyl
H
H
H
H
H
H
H
H
4e
4f
2-thienyl
Ph
4g 2-thienyl
4h Ph
5g
5h
CH3
1-naphthyl 5i
4i
4j
Ph
Ph
CH3 Ph
CH3 Ph
CH3 Ph
CH3 Ph
CH3 Ph
CH3 Bn
CH3 Bn
5j
5k
5l
5m
5n
5o
5p
5q
5r
98
96
98
98
94
98
98
98e
97e
4k 4-MeC6H4
4l 4-ClC6H4
4m 2-naphthyl
4n 2-thienyl
4o Ph
(25) (a) Veenstra, S. J.; Schimid, P. Tetrahedron Lett. 1997, 38, 997.
(b) Yadav, J. S.; Reddy, B. V. S.; Reddy, P. S. R.; Shesha Rao, M.
Tetrahedron Lett. 2002, 43, 6245. (c) Akiyama, T.; Onuma, Y. J. Chem.
Soc., Perkin Trans. 1 2002, 1157.
4p 2-naphthyl
4q Ph
Ph
CH3 Ph
H
4r
CH3
a All reactions were carried out with aldimine (1.0 mmol in 3 mL dry
ether) and triallylaluminum (0.6 mmol, 0.5 M × 1.2 mL) at 20 °C under
nitrogen for 30 min. b Isolated yields. c All reactions were carried out with
ketimine (1.0 mmol in 3 mL dry ether) and triallylaluminum (0.9 mmol,
0.5 M × 1.8 mL) at 50 °C under nitrogen for 1 h. d Reaction was carried
at 0 °C for 30 min. e Reaction was carried at 50 °C for 30 min.
(26) (a) Kobayashi, S.; Busujima, T.; Nagayama, S. Chem. Commun.
1998, 19. (b) Kobayashi, S.; Nagayama, S. J. Am. Chem. Soc. 1996, 118,
8977. (c) Aspinall, H. C.; Bissett, J. S.; Greeves, N.; Levin, D. Tetrahedron
Lett. 2002, 43, 323.
(27) Ollevier, T.; Ba, T. Tetrahedron Lett. 2003, 44, 9003.
(28) Zvolinskii, O. V.; Kryvenko, L. I.; Sergeeva, N. D.; Soldatenkov,
A. T.; Prostakov, N. D. Chem. Heterocycl. Compd. 1997, 33, 86.
3982 J. Org. Chem., Vol. 71, No. 10, 2006

SCHEME 1
of allylzinc is also troublesome, and the use of allyltin reagents
is environmentally harmful due to its toxic nature.
In conclusion, we report on a simple and general procedure
for the allylation of carbonyl derivatives using triallylaluminum.
The reaction can be applied to a wide variety of aldehydes,
ketones, aldimines, and ketimines. To the best of our knowledge,
this is the first report of the use of triallylaluminum as a reagent
for the allylation of carbonyl compounds and imines. The simple
procedures, high reaction rates, and excellent product yields
described here for the preparation of homoallylic alcohols as
well as amines using triallylaluminum, make this method an
alternative to existing processes. The main features of this
reaction are (1) the triallylaluminum is prepared from allyl
bromide and aluminum metal, not from a Grignard reagent; (2)
this is the first report of the use of triallylaluminum as a reagent
in the allylation of carbonyl compounds and imines; (3) a broad
substrate scope including sterically hindered ketones such as
adamantanone, imines, and keto esters; (4) the allylation of
ketimines without any metal catalyst is not known so far except
with Grignard reagent; and (5) the procedure is operationally
simple and provides good to excellent product yields.
triallylaluminum to afford homoallylic amines in excellent yields
at 50 °C. Irrespective of the pattern of substitution, either on
nitrogen or on the phenyl ring, excellent product yields were
observed with all ketimines. However, slight variations in
reaction times were observed for ketimines derived from
symmetrical ketones such as benzophenone and acetone. For
example, with these substrates, only a 30 min reaction time was
needed to generate products in quantitative yield. In another
variation, the chemoselectivity of this reagent was confirmed
by extending the scope of this reagent to keto esters under
different reaction conditions (Scheme 1). The R-keto ester 6
reacts with triallylaluminum at 20 °C to afford product 8 in
86% yield after 30 min, whereas in the case of the â-ketoester
7, the reaction did not proceed at the same temperature. A series
of experiments conducted at different temperatures enabled us
to establish the optimum conditions, and when the reaction was
carried out at -40 °C for 30 min, product 9 was obtained in
88% yield, with a recovery of 9% of the starting material.
Compared to other allyl reagents, the preparation of triallyl-
aluminum is relatively easy, and the experimental procedures
are simple and convenient with short reaction times. For
example, the preparation of allylsamarium reagents from sa-
marium metal and allyl bromide is more expensive, and the
reactivity of the reagent is also limited to simple aldehydes and
ketones with longer reaction times. Similarly, the preparation
Acknowledgment. Financial support provided by the Na-
tional Science Council of the Republic of China and National
Taiwan Normal University (ORD93-C) is gratefully acknowl-
edged. We also thank Dr. M. N. V. Sastry for his helpful
discussions during the preparation of the manuscript.
Supporting Information Available: Copies of 1H and 13C NMR
spectra for homoallylic alcohols and amines, detailed X-ray
information of 1-adamantyl-3-buten-1-ol. This material is available
free of charge via the Internet at http://pubs.acs.org.
JO052385F
J. Org. Chem, Vol. 71, No. 10, 2006 3983