Transformation of 1,5- and 1,6-dienes to carbocycles by hydrozirconation and oxidation with cerium(IV) compounds

Article abstract of DOI:10.1016/j.tet.2003.08.075

Cyclopentane and cyclohexane derivatives are prepared from 1,5- and 1,6-dienes in a one pot procedure by hydrozirconation, then oxidation of the generated 5- and 6-alkenylzirconocene chlorides with ammonium hexanitratocerate.

Full text of DOI:10.1016/j.tet.2003.08.075

Tetrahedron 60 (2004) 1339–1344
Transformation of 1,5- and 1,6-dienes to carbocycles by
hydrozirconation and oxidation with cerium(IV) compounds
*
Takushi Azemi, Mitsuru Kitamura and Koichi Narasaka
Department of Chemistry, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
Received 15 July 2003; accepted 6 August 2003
Abstract—Cyclopentane and cyclohexane derivatives are prepared from 1,5- and 1,6-dienes in a one pot procedure by hydrozirconation,
then oxidation of the generated 5- and 6-alkenylzirconocene chlorides with ammonium hexanitratocerate.
q 2003 Elsevier Ltd. All rights reserved.
1. Introduction
alkylzirconocenes with peroxides and peracids.4a The
oxidation of benzylarylzirconocene with Cp2FePF6 caused
the dimerization of benzyl groups to 1,2-diphenylethane.7
The intramolecular cross-coupling of organic substituents
on zirconium was accomplished by the oxidation of the
alkenyl-alkynylzirconocenes with an oxovanadium(V)
compound, giving the corresponding enynes.8 In contrast,
there has been no example for oxidative cyclization reaction
of organozirconocenes.
Radical addition to the olefinic moiety is recognized as one
of the general tools to construct molecular skeletons,
particularly cyclopentane derivatives.1 To generate radical
species, one-electron oxidation of organometallic com-
pounds has attracted considerable attention and has been
utilized mostly to generate a-keto and b-keto radical
species.2 For example, Mn(III)-based oxidation is applied
to the generation of keto radicals and the successive intra-
and intermolecular addition to alkenes.2a–e Such oxidative
methods, however, have found a quite limited application
for the generation of alkyl radicals from organometallics.
The dimerization of alkyl groups occurs by oxidation
probably due to the aggregation of alkyl metals, as being
exemplified by the dimerization of phenyl Grignard reagent
by electrode oxidation.3 Accordingly, the choice of alkyl
metals seems to be crucial to prevent such a dimerization of
alkyl groups to generate radical species by oxidation of
organometals. Alkylzirconocenes are easily prepared by
hydrozirconation of alkenes4,5 and scarcely aggregate due to
steric effects by of the cyclopentadienyl groups. We planed
to examine the oxidation of alkylzirconocenes 2 having an
internal olefinic moiety with the expectation that alkyl
radical species 3 would be generated by oxidation and add
to the olefinic moiety to give cyclization product 4 as shown
in Scheme 1. The 6-alkenylzirconocenes 2 are readily
prepared by the regioselective hydrozirconation of the less-
hindered terminal vinyl group of 1,6-dienes 1.6
Scheme 1. Oxidative cyclization of alkenylzirconocenes.
2. Results and discussion
6-Heptenylzirconocene chloride 2a was prepared in situ by
hydrozirconation of 1,1-diphenyl-1,6-heptadiene (1a) with a
slight excess of Cp2ZrHCl. In fact, the quench of the
generated alkenylziconocene with CD3COOD gave only
7-deuterio-1,1-diphenyl-1-heptane. The in situ generated
6-alkenylzirconocene intermediate 2a was submitted for
the oxidation with Ce(IV) complexes as shown in Scheme 2.
When a DMF solution of ammonium hexanitratocerate
(CAN) was added to a THF solution of 2a, the expected
cyclization product 5a was obtained in 60% yield whereas
5a was not obtained by the oxidation with Cp2FePF6,
Mn(pic)3, Ag(pic)2 (pic¼2-pyridinecarboxylato), or
Concerning the oxidation of alkylzirconocenes, the for-
mation of alcohols was reported by the reaction of
Keywords: 1,5- and 1,6-Dienes; Radical cyclization; Alkyl zirconocene;
Cerium(IV).
*
Corresponding author. Tel.: þ81-3-5841-4343; fax: þ81-3-5800-6891;
e-mail address: narasaka@chem.s.u-tokyo.ac.jp
0040–4020/$ - see front matter q 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2003.08.075

1340
T. Azemi et al. / Tetrahedron 60 (2004) 1339–1344
with CD3COOD or D2O, which gave the terminal mono-
deuterated alkenes in 76–92% yield. As compared to the
formation of 6-membered ring derivatives from 1,6-dienes,
1,5-pentadienes are converted to the corresponding cyclo-
pentane derivatives in better yields (run 1 vs. 2 and 3 vs. 4).
Within the radical addition process, the 5-membered
cyclization tend to proceed more efficiently than the
6-membered cyclization.10 Diene having trialkyl substituted
olefinic moiety 1e gave the desired cyclopentane 5e in 76%
yield. In the case of naphthyl substituted 1,5-diene 1f,
alcohol 6 and formate 7 were formed exceptionally in 56%
total yield. These compounds were formed by trapping the
benzylic cation intermediate (vide infra: C in Scheme 3)
with DMF. Dialkyl substituted alkene 1g is not suitable for a
radical accepter and the reduction product of 1g, 1-phenyl-
3-octene, was obtained in 83% yield (run 7). Thus,
trisubstituted or aryl substituted olefinic moiety was found
to be suitable as a radical acceptor. Particularly noteworthy
is that various carbonyl compounds were prepared by this
cyclization method from dienes bearing a siloxy olefinic
moiety 1h–k. For example, the cyclization of 1-phenyl-1-
siloxy-1,6- and 1,5-dienes 1h and 1i proceeded smoothly to
afford the corresponding cyclohexyl ketone 8h and
cyclopentyl ketone 8i in high yield (runs 8 and 9). Bicyclic
Scheme 2. Oxidation of alkenylzirconocene 2a by using Ce(IV) salts.
Cu(OAc)2.9 The yield of 5a was increased to 72% by use of
tetrabutylammonium hexanitratocerate (CBAN).
This oxidative method was applied to the cyclization of
various 1,5- and 1,6-dienes, and the results are summarized
in Table 1. Prior to the oxidation, the hydrozirconation of
the teminal vinyl group of dienes (1a–k) was confirmed by
quenching the in situ generated 5-or 6-alkenylzirconocene
Table 1. The oxidative intramolecular cycloaddition of various 1,5- and 1,6-dienes with CBANa
Run
Substrates
Products
Yield (%)
n¼2 1a
n¼1 1b
n¼2 5a
n¼1 5b
1
2
72
83
n¼2 1cb
n¼1 1db
n¼2 5c
n¼1 5d
3
4
39
72
5
1e
5e
76
1f
R¼OH 6
42
14
6c
R¼OCOH 7
7d
1g
0
n¼2 1he
n¼1 1if
n¼2 8h
n¼1 8i
8
9
71
78
1jb
8j
10
11
36
75
1k
8kg
aReaction and conditions: (1) diene, Cp2ZrHCl (1 equiv.), THF, rt, 1 h, (2) CBAN (2 equiv.), DMF, rt, 12 h; bE, Z mixture. The stereochemistry is not
f
determined; cHydrozirconation was carried out at 210 8C for 5 h; dHydrozirconation was carried out at 210 8C for 4 h; eE/Z¼13:1; E/Z¼10:1; gSingle
diastereomer. The stereochemsitry is not determined.

T. Azemi et al. / Tetrahedron 60 (2004) 1339–1344
1341
Scheme 3. A plausible mechanism of the cyclization of alkenylzirconocene 2 with CBAN.
and tricyclic ketones 8j and 8k could be also synthesized
from olefinic silyl enol ethers 1j and 1k, respectively (runs
10 and 11).
standard. High-resolution mass spectra were recorded on a
JEOL MS-700P mass spectrometer (EI: operating at 70 eV).
All melting points were uncorrected. Yields quoted are
based on isolated mass. All reactions were carried out under
an argon atmosphere. Et2O and THF were dried by
distillation from sodium and benzophenone. Dimethly-
formamide (DMF) was dried over by P2O5 for 24 h followed
by distillation, then was distilled from CaH2 and sub-
A plausible mechanism of the present cyclization of
alkenylzirconocene 2 with CBAN is depicted in Scheme 3.
Alkenylzirconocene 2 is oxidized with CBAN to give cation
radical species A and the successive radical cyclization
occurs to give radical intermediate 4 (Path a). 4 might be
formed via alkenylcerium(IV) intermediate B generated by
the transmetallation between 2 and CBAN (Path b). Further
oxidation of the radical intermediate 4 with CBAN gives
the corresponding cation species C and the successive
deprotonation or desilylation from C affords cycloalkenes 5
or cycloalkyl ketones 8.
˚
sequently stored over 4 A molecular sieves. Cp2ZrHCl was
purchased from Aldrich and was used as received.
Ammonium hexanitratocerate [(NH4)2Ce(NO3)6, (CAN)]
was dried under pressure (0.5 mmHg) for 6 h at 80 8C.
Tetrabutylammonium hexanitratocerate [(n-Bu4N)2Ce(NO3)6,
(CBAN)] was prepared according to the literature pro-
cedure.11 Flash column chromatography was carried out on
silica-gel [Kanto Chemical Co., Inc. Silica gel 60N
(spherical, neutral)]. Preparative TLC was performed on
silica-gel (Wakogel B-5F).
In conclusion, we developed the method of the synthesis of
cyclopentane and cyclohexane derivatives from 1,5- and
1,6-dienes in a one pot procedure by hydrozirconation, and
the successive oxidation of the generated 5- and 6-alkenyl-
zirconocene chlorides with Ce(IV) compounds.
3.2. General procedure for oxidation of
alkenyl-zirconocene
Freshly distilled dienes (0.20 mmol) were added to a THF
suspension (2.0 mL) of Cp2ZrHCl (114 mg, 0.21 mmol)
under argon atmosphere at rt, and the suspension was stirred
for 1 h (a white suspension turned to a yellow solution). To
this solution was added CBAN (439 mg, 0.42 mmol) in
DMF (4.5 mL) at rt, and the mixture was allowed to stir for
12 h. After the reaction was quenched with water, the
mixture was filtered through a Celite pad. The filtrate was
extracted with EtOAc, and the combined organic extracts
were washed with water and brine, and dried over Na2SO4.
3. Experimental
3.1. General
IR spectra were measured with a Horiba FT 300-S
spectrometer. 1H NMR (500 MHz) and 13C NMR
(125 MHz) were recorded on a Bruker DRX 500 or an
Avance 500 spectrometer with CHCl3 (d¼7.24 for 1H
NMR) and CDCl3 (d¼77.0 for 13C NMR) as an internal

1342
T. Azemi et al. / Tetrahedron 60 (2004) 1339–1344
The solvent was evaporated in vacuo to give a crude
product, which was purified by preparative TLC.
3.83 (t, J¼6.8 Hz, 1H), 6.97–6.99 (m, 1H), 7.06–7.21 (m,
3H); 13C NMR (CDCl3) d 20.8, 26.2, 27.7, 29.2, 53.7, 125.9,
126.8, 129.2, 129.5, 133.6, 137.4, 210.6.
3.2.1. (Diphenylmethylene)cyclohexane (5a).12 72%
1
Yield; mp 73–74 8C; H NMR (CDCl3) d 1.56–1.60 (m,
3.2.11. 1,2,3,3a,8a-Pentahydrocyclopenta[a]inden-8-one
(8k).19 75% Yield; 1H NMR (CDCl3) d 1.10–1.13 (m, 1H),
1.55–1.58 (m, 1H), 1.81–1.88 (m, 2H), 1.96–2.00 (m, 2H),
3.01–3.05 (m, 1H), 3.73 (t, J¼7.8 Hz, 1H), 7.31 (t,
J¼7.5 Hz, 1H), 7.44 (dd, J¼8.0, 1.0 Hz, 1H), 7.55–7.59
(m, 1H), 7.94 (d, J¼8.0 Hz, 2H); 13C NMR (CDCl3) d 24.8,
30.8, 33.1, 43.9, 52.3, 123.1, 125.9, 127.3, 135.1, 137.4,
158.7, 210.2.
6H), 2.23–2.25 (m, 4H), 7.10–7.29 (m, 10H); 13C NMR
(CDCl3) d 26.8, 28.7, 32.4, 126.0, 127.8, 129.8, 134.5,
139.1, 143.1.
3.2.2. (Diphenylmethylene)cyclopentane (5b).13 83%
1
Yield; mp 61–63 8C; H NMR (CDCl3) d 1.65–1.71 (m,
4H), 2.23–2.25 (m, 4H), 7.15–7.31 (m, 10H); 13C NMR
(CDCl3) d 26.8, 33.2, 126.0, 127.9, 129.2, 134.3, 138.9,
143.5.
3.3. Preparation of starting materials
3.2.3. 1-Cyclohexyl-1-phenylethene (5c).14 39% Yield; 1H
NMR (CDCl3) d 1.19–1.38 (m, 6H), 1.80–1.88 (m, 4H),
2.42–2.48 (m, 1H), 5.04 (s, 1H),?5.16 (s, 1H), 7.28–7.37
(m, 5H).
1,1-Diphenyl-1,5-hexadiene (1a),20 1,1-diphenyl-1,6-hepta-
diene (1b),20 t-butyldimethyl(1-phenylhexa-1,5-dienyloxy)-
silane (1h),21 and t-butyldimethyl(1-phenylhepta-1,6-
dienyloxy)silane (1i),21 were prepared according to the
literature procedures.
3.2.4. 1-Cyclopentyl-1-phenylethene (5d).15 72% Yield;
1H NMR (CDCl3) d 1.23–2.02 (m, 7H), 2.18–2.36 (m,
1H), 2.94 (q, J¼8.1 Hz, 1H), 5.05 (d, J¼1.1 Hz, 1H),
5.15 (d, J¼1.1 Hz, 1H), 7.15–7.38 (m, 5H); 13C NMR
(CDCl3) d 24.8, 32.0, 44.5, 110.0, 126.5, 126.9, 128.0,
143.1, 152.8.
3.3.1. 7-Phenyl-1,6-octadiene (1c). Potassium t-butoxide
(1.0 g, 8.9 mmol) was added to hexenyl triphenylphos-
phonium bromide22 (3.8 g, 8.9 mmol) in THF (50 mL).
After stirring for 1.5 h at rt, a THF solution (6 mL) of
acetophenone (713 mg, 5.94 mmol) was added. After 2 h,
the reaction mixture was filtered on a short silica-gel column
with ether, and the filtrate was concentrated in vacuo. The
crude product was distilled under 1.5 mmHg in Kugelrohr
apparatus to give 1c (1.06 g, 96%) as an oil. E, Z mixture.
Bp 110–120 8C/1.5 mmHg; 1H NMR (CDCl3) d 1.44–1.56
(m, 2H), 1.97 (s, 3H), 2.02–2.20 (m, 4H), 4.85–4.99
(m, 2H), 5.69–5.83 (m, 2H), 7.12–7.34 (m, 5H),
3.2.5. (4-Cyclopentyl-3-cyclohexenyl)benzene (5e). 76%
Yield; 1H NMR (CDCl3) d 1.37–2.36 (m, 15H), 2.64–2.83
(m, 1H), 5.52 (d, J¼5.1 Hz, 1H), 7.16–7.33 (m, 5H).
3.2.6. Cyclopentyl-(1-naphthyl)methanol (6). 42% Yield;
IR (neat) 3390, 2950, 2870, 800, 780 cm21 1H NMR
;
(CDCl3) d 1.23–1.28 (m, 1H), 1.41– 1.68 (m, 6H), 1.86–
1.96, (m, 1H), 2.49–2.57 (m, 1H), 5.20 (d, J¼7.6 Hz, 1H),
7.40–7.52 (m, 3H), 7.58 (d, J¼7.0 Hz, 1H), 7.77 (d,
J¼8.2 Hz, 1H), 7.83–7.86 (m, 1H), 8.20–8.24 (m, 1H); 13C
NMR d 25.6, 25.7, 29.0, 29.7, 46.5, 75.3, 123.6, 123.9,
125.3, 125.4, 125.8, 128.0, 128.8, 130.8, 133.9; FAB HRMS
(MþH)þ calcd for C16H19O 227.1437, found 227.1428.
3.3.2. 6-Phenyl-1,5-heptadiene (1d). Potassium t-butoxide
(1.40 g, 12.5 mmol) was added to pentenyl triphenylphos-
phonium bromide23 (5.13 g, 12.5 mmol) in THF (80 mL).
After stirring for 1.5 h at rt, a THF solution (10 mL) of
acetophenone (1.00 g, 8.33 mmol) was added. After 2 h, the
reaction mixture was filtered on a short silica-gel column
with ether, and the filtrate was concentrated in vacuo. The
crude product was distilled under 1.5 mmHg in Kugelrohr
apparatus to give 1d (1.36 g, 95%) as an oil. E, Z mixture.
3.2.7. Cyclopentyl-(1-naphthyl)methylformate (7). 14%
1
Yield; oil; IR (neat) 2960, 2870, 1720, 1170, 800, 780; H
1
NMR (CDCl3) d 1.15–1.87 (m, 8H), 2.65–2.73 (m, 1H),
6.45 (d J¼8.6 Hz, 1H), 7.42–7.55 (m, 4H), 7.80 (d,
J¼8.0 Hz, 1H), 7.86 (d, J¼8.1 Hz, 1H), 8.14 (s, 1H), 8.26
(d, J¼8.1 Hz, 1H); 13C NMR d 25.2, 25.3, 29.4, 29.5, 45.1,
123.6, 125.0, 125.2, 125.6, 126.2, 128.6, 128.9, 130.6,
133.8, 135.8, 160.6; FAB HRMS (MþH)þ calcd for
C17H19O2 255.1380, found 255.1386.
Bp 110–120/1.5 mmHg; H NMR (CDCl3) d 2.03 (s, 3H),
2.07–2.10 (m, 4H), 4.91–4.99 (m, 2H), 5.45–5.48 (m, 1H),
5.72–5.80 (m, 1H), 7.17–7.19 (m, 2H), 7.21–7.25 (m, 1H),
7.31–7.34 (m, 2H); 13C NMR (CDCl3) d 25.5, 28.4, 34.1,
114.5, 126.4, 126.8, 127.9, 128.0, 136.5, 138.3, 142.0.
3.3.3. 5-(4-Phenylcyclohexylidene)-1-pentene (1e). Potas-
sium t-butoxide (1.49 g, 13.3 mmol) was added to
1
3.2.8. Cyclohexyl phenyl ketone (8h).16 71% Yield; H
pentenyltriphenylphosphonium
bromide23
(5.47 g,
NMR (CDCl3) d 1.24–1.90 (m, 10H), 3.26 (m, 1H), 7.41
(m, 3H), 7.94 (m, 2H); 13C NMR (CDCl3) d 25.8, 25.9, 29.4,
45.6, 128.2, 128.5, 132.7, 136.3, 203.9.
13.3 mmol) in THF (80 mL). After stirring for 1.5 h at rt, a
THF solution (10 mL) of 4-phenylcyclohexanone (1.54 g,
8.87 mmol) was added. After stirring for 2 h, the reaction
mixture was filtered on a short silica-gel column with ether,
and the filtrate was concentrated in vacuo. The crude
product was distilled under 1.5 mmHg in Kugelrohr
apparatus gave 1e (1.99 g, 99%) as an oil. Bp 130–
140 8C/1.0 mmHg; IR (neat) 2920, 2360, 1490, 1440, 910,
1
3.2.9. Cyclopentyl phenyl ketone (8i).17 78% Yield; H
NMR (CDCl3) d 1.58–1.72 (m, 4H), 1.76–1.94 (m, 4H), 3.70
(q, J¼7.8 Hz, 1H), 7.41–7.59 (m, 3H), 7.94–7.97 (m, 2H).
1
3.2.10. 1-(1,2,3,4-Tetrahydro-1-naphthyl)ethanone
(8j).18 36% Yield; 1H NMR (CDCl3) d 1.72–1.80 (m,
1H), 1.88–2.08 (m, 3H), 2.12 (s, 3H), 2.76–2.82 (m, 2H),
760, 700 cm21; H NMR (CDCl3) d 1.40–1.53 (m, 2H),
1.85–1.90 (m, 1H), 1.94–1.96 (m, 2H), 2.11–2.21 (m, 5H),
2.28–2.31 (m, 1H), 2.65–2.73 (m, 2H), 4.97–5.06 (m, 2H),

T. Azemi et al. / Tetrahedron 60 (2004) 1339–1344
1343
5.16–5.17 (m, 1H), 5.80–5.89 (m, 1H), 7.17–7.21 (m, 3H),
7.26–7.30 (m, 2H); 13C NMR (CDCl3) d 26.7, 28.4, 34.3,
35.1, 35.9, 36.8, 44.8, 114.4, 121.3, 125.9, 126.8, 128.3,
138.6, 138.7, 147.1. HRMS calcd for C17H22 226.1721,
found 226.1739.
To a solution of 2-(2-bromobenzyl)-2-methyl-1,3-dioxane
(2.0 g, 7.0 mmol) in THF (12 mL) was added buthyllithium
(7.71 mmol) at 278 8C. After stirring for 1 h, allyl bromide
(1.01 g, 8.41 mmol) in THF (5 mL) was added to the
reaction mixture at 278 8C. After the reaction mixture was
warmed to rt, the reaction was quenched with water. From
the mixture organic materials were extracted with EtOAc,
and the combined organic extracts were washed with water
followed by brine. The organic layer was dried over Na2SO4
and the solvent was removed in vacuo. To a solution of the
crude product in MeOH (10 mL) was added 1 N HCl
(0.5 mL). After stirring for 2 h, the reaction mixture was
poured into water and extracted with EtOAc. The combined
organic extracts were washed with water followed by brine.
The organic layer was dried over Na2SO4 and the solvent
was removed in vacuo. The crude product was purified by
column chromatography on silica-gel (6:1:1 hexane/
EtOAc/benzene) to give 1-(2-allyl-phenyl)propan-2-one
[22% yield; 1H NMR (CDCl3) d 2.14 (s, 3H), 3.73 (s,
2H), 3.34 (d, J¼11.5 Hz, 2H), 4.94–5.08 (m, 1H), 5.84–
5.96 (m, 1H), 7.12–7.34 (m, 4H).]
3.3.4. (5Z)-6-(1-Naphthyl)-1,5-hexadiene (1f). Potassium
t-butoxide (1.46 g, 13.0 mmol) was added to pentenyl
triphenylphosphonium bromide23 (5.35 g, 13.0 mmol) in
THF (80 mL). After stirring for 1 h at rt, a THF solution
(10 mL) of 1-naphthaldehyde (1.35 g, 8.67 mmol) was
added. After stirring for 2 h, the reaction mixture was
filtered on a short silica-gel column with ether, and the
filtrate was concentrated. The crude product was distilled
under 1.0 mmHg in Kugelrohr apparatus to give 1f (1.72 g,
95%) as an oil. Bp 120–130 8C/1.0 mmHg; IR (neat) 3060,
1
3010, 2920, 2340, 1640, 1510, 910, 780 cm21; H NMR
(CDCl3) d 2.16 (dt, J¼7.6, 6.6 Hz, 2H), 2.27 (dt, J¼7.2,
6.6 Hz, 2H), 4.93 (d, J¼10.2 Hz, 1H), 4.98 (d, J¼17.2 Hz,
1H), 5.76 (ddt, J¼17.2, 10.2, 6.6 Hz, 1H), 5.93 (dt, J¼11.5,
7.2 Hz, 1H), 6.90 (d, J¼11.5 Hz, 1H), 7.34 (d, J¼11.5,
7.0 Hz, 1H), 7.43–7.50 (m, 3H), 7.76 (d, J¼11.5 Hz, 1H),
7.84–7.86 (m, 1H), 7.99 (m, 1H); 13C NMR (CDCl3) d 28.0,
33.8, 125.0, 125.2, 125.7, 125.8, 126.3, 127.2, 127.4, 128.3,
131.9, 133.4, 133.5, 133.6, 134.7, 138.1; HRMS calcd for
C16H16O 208.1252, found 208.1228.
To a suspension of NaH (52.1 mg, 2.17 mmol) in THF
(2 mL) was added a THF (4 mL) solution of 1-(2-allyl-
phenyl)propan-2-one (291 mg, 1.67 mmol) at 0 8C. After
the mixture was allowed to warm to rt with stirring, a THF
(3 mL) solution of t-butyldimethylsilyl chloride (327 mg,
2.17 mmol) was added. After stirring for 2 h, the reaction
was quenched with sat. NaHCO3 aq. The organic layer was
washed twice with brine and dried over Na2SO4. After the
solvent was removed in vacuo, the residue was roughly
purified by column chromatography deactivated by Et3N
(hexane/EtOAc¼9/1) to give 1j, which was further purified
by distillation under 1.0 mmHg to give pure 1j (0.457 g,
95%) as an oil. E, Z mixture; Bp 150–160 8C/1.0 mmHg; 1H
NMR (CDCl3) d 20.03 (s, 6H), 0.83 (s, 9H), 1.97 (s, 3H),
3.36–3.38 (m, 2H), 4.96–5.05 (m, 2H), 5.51 (s, 1H), 5.90–
6.01 (m, 1H), 7.08–7.16 (m, 3H), 7.60–7.63 (m, 1H).
3.3.5. (5Z)-8-Phenyl-1,5-octadiene (1g). Potassium t-but-
oxide (1.31 g, 11.7 mmol) was added to pentenyl triphenyl-
phosphonium bromide23 (4.81 g, 11.7 mmol) in THF
(80 mL). After stirring for 1 h at rt, a THF solution
(10 mL) of hydrocinnamaldehyde (1.21 g, 9.00 mmol) was
added. After stirring for 2 h, the reaction mixture was
filtered on a short silica-gel column with ether, and the
filtrate was concentrated in vacuo. The crude product was
distilled under 1.0 mmHg in Kugelrohr apparatus to give 1 g
(1.68 g, 99%) as an oil. Z isomer. Bp 100–110 8C/
1.0 mmHg; IR (neat) 3000, 2850, 1640, 1500, 1450, 910,
1
720, 700 cm21; H NMR (CDCl3) d 2.01–2.10 (m, 4H),
2.34–2.08 (m, 2H), 2.66 (t, J¼7.8 Hz, 2H), 4.93–5.01 (m,
2H), 5.36–5.47 (m, 2H), 5.73–5.81 (m, 1H), 7.17–7.20 (m,
3H), 7.25–7.29 (m, 2H); 13C NMR (CDCl3) d 26.6, 29.2,
33.7, 35.9, 114.6, 125.8, 128.2, 128.5, 129.1, 129.7, 138.3;
HRMS calcd for C14H18 186.1409, found 186.1396, 142.1.
3.3.7. (3-Allyl-3H-1-indenyloxy)-t-butyldimethylsilane
(1k). To a solution of lithium diisopropylamide [prepared
by the reaction of buthyllithium (10.7 mmol) and diisopro-
pylamine (1.08 g, 10.7 mmol) in THF (20 mL)] was added a
THF (12 mL) solution of 3-(t-butyldimethylsilyloxy)indene25
(2.49 g, 10.1 mmol) at 278 8C. After stirring for 1 h, allyl
bromide (1.32 g, 11.0 mmol) in THF (10 mL) was added to
the reaction mixture at 278 8C. After the reaction mixture
was warmed to rt, the reaction was quenched with water.
From the mixture organic materials were extracted with
EtOAc, and the combined organic extracts were washed
with water followed by brine. The organic layer was dried
over Na2SO4 and the solvent was removed in vacuo. The
yellow residue was distilled under 0.1 mmHg to give 1k
(2.20 g, 76%) as a yellow oil. Bp 85–100 8C/0.1 mmHg; 1H
NMR (CDCl3) d 20.02 (s, 1H), 0.83 (s, 1H), 1.97 (s, 3H),
3.37 (d, J¼6.2 Hz 2H), 4.96–5.05 (m, 2H), 5.90–6.01 (m,
1H), 7.08–7.16 (m, 4H).
3.3.6. [2-(2-Allylphenyl)-1-methylethenyloxy]-t-butyldi-
methylsilane (1j). p-Toluenesulfonic acid monohydrate
(38.0 mg, 0.20 mmol) and 1,3-propanediol (4.57 g, 60.0 mmol)
were added to a solution of 1-(2-bromophenyl)propan-2-
one24 (4.20 g, 19.7 mmol) in benzene (60 mL). After the
reaction mixture was refluxed for 10 h, the reaction was
quenched with sat. NaHCO3 aq. The organic materials were
extracted with EtOAc, and the organic extract was washed
with water followed by brine. The organic layer was dried
over Na2SO4 and the solvent was removed in vacuo. The
crude product was purified by column chromatography on
silica-gel deactivated by Et3N (6:1 hexane/EtOAc) to give
2-(2-bromobenzyl)-2-methyl-1,3-dioxane. [97% yield; 1H
NMR (CDCl3) d 1.22 (s, 3H), 1.45–1.55 (m, 1H), 1.67–
1.77 (m, 1H), 3.14 (s, 2H), 3.86 (dd, J¼12.5, 8.5 Hz, 4H),
6.92–6.97 (m, 1H), 7.08–7.14 (m, 1H), 7.30–7.33 (m, 1H),
7.40–7.43; 13C NMR (CDCl3) d 19.9, 25.4, 43.2, 59.8, 99.6,
126.0, 126.9, 127.9, 132.4, 132.6, 136.7.]
Acknowledgements
This research was supported by a Grant-in-Aid for Scientific
Research on Priority Areas (A) ‘Exploitation of Multi-Element

1344
T. Azemi et al. / Tetrahedron 60 (2004) 1339–1344
6. Hart, D. W.; Schwartz, J. J. Am. Chem. Soc. 1974, 96, 8115.
7. Brokowsky, S. L.; Jordan, R. F.; Hinch, G. D. Organometallics
1991, 10, 1268.
Cyclic Molecules’ and a Grant-in-Aid for The 21st Century
COE Program for Frontiers in Fundamental Chemistry from
the Ministry of Education, Culture, Sports, Science and
Technology, Japan.
8. Ishikawa, T.; Ogawa, A.; Hirao, T. J. Organomet. Chem. 1999,
575, 76.
9. Although addition of bases such as K2CO3, NaHCO3, Et3N,
pyridine, and diisopropyl amine was examined to neutralize
nitric acid that would form with the progress of the reaction,
the yield of cyclization product 3a was not increased.
10. Baldwin, J. E. J. Chem. Soc. Chem. Commun. 1976, 734.
11. Muathen, H. A. Indian J. Chem., B 1992, 522.
12. McMurry, J. E.; Fleming, M. P.; Kees, K. L.; Krepski, L. R.
J. Org. Chem. 1978, 43, 3255.
References and Notes
1. Curran, P. D. Chem. Rev. 1991, 91, 1237.
2. Mn (a) Snider, B. B. Chem. Rev. 1996, 96, 339. (b) Nishino,
H.; Yoshida, T.; Kurosawa, K. Bull. Chem. Soc. Jpn 1991, 64,
1097. (c) Narasaka, K. Pure. Appl. Chem. 1997, 69, 601. (d)
Iwasawa, N.; Funakoshi, M.; Hayakawa, S.; Ikeno, T.;
Narasaka, K. J. Org. Chem. 1997, 62, 3762. (e) Hirao, V.;
Fujii, T.; Ohshiro, Y. Tetrahedron Lett. 1994, 35, 8005. (f)
Clark, A. J.; Dell, C. P.; McDonagh, M. J.; Geden, J.;
Mawdsley, P. Org. Lett. 2003, 5, 2063. (g) Corey, E. J.; Ghosh,
A. K. Chem. Lett. 1997, 223. Cu (h) Snider, B. B.; Kwon, T.
J. Org. Chem. 1997, 62, 3762. Fe (i) Sartori, G.; Maggi, R.;
Bigi, F.; Arienti, A.; Casnati, G.; Bocelli, G.; Mori, G.
Tetrahedron 1992, 48, 9483. (j) Jahn, U.; Hartmann, P.
J. Chem. Soc., Perkin Trans. 1 2001, 2227. Co (k) Iqbal, J.;
Praveen, T. K.; Manogran, S. Tetrahedron 1989, 30, 4701. (l)
Tarakeshwer, P.; Iqbal, J.; Manogran, S. Tetrahedron 1991,
47, 297. Ce (m) Arai, N.; Narasaka, K. Chem. Lett. 1995, 987.
(n) Kohno, Y.; Narasaka, K. Bull. Chem. Soc. Jpn 1996, 68,
322. (o) Nair, V.; Matthew, J.; Radhakrishnan, K. J. J. Chem.
Soc., Perkin Trans. 1 1996, 1487.
13. Newcomb, M.; Choi, S. Y.; Horner, J. H. J. Org. Chem. 1999,
64, 1225.
14. Tokunaga, Y.; Sakakura, T.; Tanaka, M. J. Mol. Cata. 1989,
56, 305.
15. Avasthi, K.; Baba, T.; Suzuki, A. Tetrahedron Lett. 1980, 21,
945.
16. Rieke, R. D.; Hanson, M. V.; Brown, J. D.; Niu, Q. J. Org.
Chem. 1996, 61, 2726.
17. Blay, G.; Fernandez, I.; Formentin, P.; Monje, B.; Pedro, J. R.;
Ruiz, R. Tetrahedron 2001, 576, 1075.
18. Mejer, S.; Pacut, R. Polish J. Chem. 1978, 52, 529.
19. Foehlisch, B.; Schwaiger, G. Liebigs Ann. Chem. 1975, 1, 1.
20. Eisch, J. J.; Merkley, J. H. J. Am. Chem. Soc. 1979, 101, 1148.
21. Snider, B. B.; Kwon, T. J. Org. Chem. 1992, 57, 2399.
22. Hauser, C. F.; Brooks, T. W.; Miles, M. L.; Raymond, M. A.;
Butler, G. B. J. Org. Chem. 1963, 24, 372.
3. Morgat, J. L.; Pallaud, R.; Hebd, C. R. Seances Acad. Sci.
1965, 260, 5579.
23. Taber, D. F.; Rahimizadeh, M.; You, K. K. J. Org. Chem.
1995, 60, 529.
4. For reviews see: (a) Schwartz, J.; Labinger, J. A. Angew.
Chem., Int. Ed. Engl. 1976, 15, 333. (b) Negishi, E.;
Takahashi, T. Synthesis 1988, 1. (c) Wipf, P. Synthesis 1993,
537. (d) Wipf, P.; Jahn, H. Tetrahedron 1996, 52, 12853.
5. Blackburn, T. F.; Labinger, J. A.; Schwarts, J. Tetrahedron
Lett. 1975, 3041.
24. Viswanathan, R.; Prabhakaran, E. N.; Plotkin, M. A.;
Johnston, J. N. J. Am. Chem. Soc. 2003, 125, 163.
25. Boger, D. L.; Mathvink, J. Org. Chem. 1992, 57, 1429.