Formation and rearrangement of dithioxo- and diselenoxophosphoranes carrying bulky 4-t-butyl-2,6-bis(methoxyalkyl)phenyl groups

Article abstract of DOI:10.1016/S0040-4020(99)00771-1

[4-t-Butyl-2,6-bis(1-methoxy-1-methylethyl)phenyl]phosphine, [4-t-butyl- 2,6-bis(2-methoxy-1,1-dimethylethyl)phenyl]phosphine, and [4-t-butyl-2,6- bis(3-methoxy-1,1-dimethylpropyl)phenyl]phosphine were prepared and allowed to react with sulfur or selenium, to give heterocyclic compounds containing phosphorus-oxygen bond, via rearrangement of the methyl moiety of the methoxy group.

Full text of DOI:10.1016/S0040-4020(99)00771-1

TETRAHEDRON
Pergamon
Tetrahedron 56 (2000) 43–55
Formation and Rearrangement of Dithioxo- and
Diselenoxophosphoranes Carrying Bulky
4-t-Butyl-2,6-bis(methoxyalkyl)phenyl Groups
*
Masaaki Yoshifuji, Masahiko Nakazawa, Takeshi Sato and Kozo Toyota
Department of Chemistry, Graduate School of Science, Tohoku University, Aoba, Sendai 980-8578, Japan
Received 5 March 1999; accepted 9 June 1999
Abstract—[4-t-Butyl-2,6-bis(1-methoxy-1-methylethyl)phenyl]phosphine, [4-t-butyl-2,6-bis(2-methoxy-1,1-dimethylethyl)phenyl]phos-
phine, and [4-t-butyl-2,6-bis(3-methoxy-1,1-dimethylpropyl)phenyl]phosphine were prepared and allowed to react with sulfur or selenium,
to give heterocyclic compounds containing phosphorus–oxygen bond, via rearrangement of the methyl moiety of the methoxy group. ᭧ 1999
Elsevier Science Ltd. All rights reserved.
Compounds with multiple-bonded heavier main-group
elements, such as phosphorus, are currently of interest.1
By utilizing an extremely bulky 2,4,6-tri-t-butylphenyl
group (hereafter abbreviated as Ar; Chart 1) as a sterically
protecting auxiliary, we and others have successfully
prepared various types of multiple bonded phosphorus
compounds, such as diphosphene 1 (Chart 2),2 dithioxo-
phosphorane (thioxophosphine sulfide) 2,3 and diselenoxo-
phosphorane (selenoxophosphine selenide) 3.4 Recently, we
have developed some novel substituents, such as the
2,4-di-t-butyl-6-(dimethylamino)phenyl group (abbreviated
as Mx),5 the 2,4-di-t-butyl-6-methoxyphenyl group
(abbreviated as Mox),6 the 2,4-di-t-butyl-6-(dimethyl-
aminomethyl)phenyl group (abbreviated as Mamx),7 the
2,4-di-t-butyl-6-(methoxymethyl)phenyl group (abbrevi-
ated as Momx),8 the 4-t-butyl-2,6-bis(dimethylamino-
methyl)phenyl group (abbreviated as Mamt),9 and the 2,4-
di-t-butyl-6-[1,1-dimethyl-2-(dimethylamino)ethyl]phenyl
group (abbreviated as Maar),10 having both a bulky t-butyl
group and an electron donating part at the o-positions.
Contrary to this, the Mox-substituted dithioxophosphorane
6 was not stable, suggesting a weak intramolecular inter-
action within the molecule. When a solution of 6 was
concentrated, the compound dimerized to 7 (Scheme 1).6a
On heating, the monomeric dithioxophosphorane 6 was re-
generated from the dimer 7.6b As for a selenium congener of
6, we have not been successful in preparation of the Mox-
substituted diselenoxophosphorane 8. An attempted
preparation of 8 by the reaction of MoxPH2 with selenium
in the presence of a base, according to the preparative
method of diselenoxophosphoranes with the Mx-type
substituents, resulted in the formation of a heterocyclic
compound 9.6c
This striking difference in the stabilizing abilities between
the Mx group and the Mox group prompted us to examine
the effect of oxygen-functional group on the –P(yS)2 and
–P(ySe)2 moieties by using other type of substituents. As a
part of our investigation on the modified 2,4,6-tri-t-butyl-
phenyl group, we now report the introduction of 4-t-butyl-
2,6-bis(1-methoxy-1-methylethyl)phenyl group (a in Chart
3), 4-t-butyl-2,6-bis(2-methoxy-1,1-dimethylethyl)phenyl
group (b) and 4-t-butyl-2,6-bis(3-methoxy-1,1-dimethyl-
propyl)phenyl group (c).
Dithioxo- and diselenoxophosphorane derivatives 4 and 5,5
bearing the Mx group, are highly stabilized, mainly by intra-
molecular coordination (compared with the kinetically
stabilized ‘genuine’ dithioxophosphorane 2 and diselenoxo-
phosphorane 3). The intramolecular coordination in the
solid state was confirmed by X-ray crystallography in the
case of the compounds bearing the Mx-type substituents11
as well as the compounds with the Mamx7 and the Maar
substituents.10
Results and Discussion
Preparation of 2-bromo-5-t-butyl-1,3-bis(methoxyalkyl)
benzenes
In order to introduce a bulky 4-t-butyl-2,6-bis(methoxy-
alkyl)phenyl moiety into a molecule, the corresponding
bromobenzenes 10a–c were prepared as follows. Bromo-
benzene 10a was prepared by a route shown in Scheme 2.
Keywords: phosphorus heterocycles; phosphines; rearrangements; steric
and strain effects.
* Corresponding author. Tel.: ϩ81-22-217-6558; fax: ϩ81-22-217-6562;
e-mail: yoshifj@mail.cc.tohoku.ac.jp
0040–4020/00/$ - see front matter ᭧ 1999 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020(99)00771-1

44
M. Yoshifuji et al. / Tetrahedron 56 (2000) 43–55
Chart 1.
Chart 2.
Scheme 1.
Oxidation
of
2-bromo-5-t-butyl-1,3-dimethylbenzene
derivative 18. While methylation of 19 with an excess of
dimethyl sulfate gave the mono-methoxy derivative 20
(Chart 4) as a major product (59%) with only a trace amount
(3%) of the desired dimethoxy derivative 10b, methylation
of 19 using MeI/NaH afforded 10b in good yield (93%).
(11)12a afforded the isophthalic acid derivative 12,12b
which was then converted to the corresponding dimethyl
ester 13. The ester 13 was then allowed to react with methyl-
magnesium bromide to give 2-bromo-5-t-butyl-1,3-bis(1-
hydroxy-1-methylethyl)benzene (14) in 64% yield.
Methylation of 14 afforded 10a in 92% yield.
Similarly, bromobenzene 10c was prepared from a synthetic
intermediate 18 by a route as shown in Scheme 4. Thus, the
Wittig reaction of the diformyl derivative 18 with methyl-
enetriphenylphosphorane afforded 21 (91%). Hydroboration
of 21 gave diol 22 as a major product (72%) along with
the Markovnikov-type product 23 (24%, Chart 4). Then
22 was methylated with MeI/NaH to give 10c almost
quantitatively.
Bromobenzene 10b was prepared as shown in Scheme 3.
2-Bromo-1,3-bis(bromomethyl)-5-t-butylbenzene (15)13 was
allowed to react with potassium cyanide in acetonitrile in
the presence of 18-crown-6 to afford the dicyano derivative
16 in 89% yield. Methylation at the benzyl position14 of 16
with MeI/KOH in dimethyl sulfoxide gave 2-bromo-5-t-
butyl-1,3-bis(1-cyano-1-methylethyl)benzene (17) in 65%
yield. Successive reduction of the cyano group in 17 with
diisobutyl aluminum hydride and lithium aluminum hydride
afforded the dihydroxy derivative 19 via the diformyl
Chart 3.
Scheme 2.

M. Yoshifuji et al. / Tetrahedron 56 (2000) 43–55
45
Scheme 3.
Scheme 4.
Preparation of primary phosphines and diphosphenes
with methanol in the presence of triethylamine, compounds
29a,b were obtained via 28a,b [28a: dP (THF–C6D6)ˆ164
(m); 28b: dP (CDCl3)ˆ144.6 (br. s)].
Since bromobenzenes 10a–c were prepared as described
above, attempted preparation of primary phosphines bear-
ing the substituents a–c were made by a normal procedure
via phosphonous dichlorides (Scheme 5). At first, appro-
priate reaction conditions were determined for metallation
of bromobenzenes 10a–c with butyllithium in THF. As
for compounds 10a,b, the best results were obtained at
room temperature and the corresponding benzene deriva-
tives 25a,b were formed in good yields (96 and 92%,
respectively), after quenching of the reaction mixtures
with water. Although lithiation of 10c proceeded effec-
tively (97% yield of 25c) at Ϫ78ЊC, attempted lithiation
of 10c at room temperature gave a complex mixture of
products.
On the other hand, the relatively stable phosphonous
dichloride 26c reacted with methanol to give 31 via 30
[dP (THF–C6D6)ˆ175 (m)]. It should be noted that
successive reaction of 24c with PCl3 and methanol in aceto-
nitrile (instead of THF) afforded 29c [dP (CDCl3)ˆ28.3 (dd,
3
1JPHˆ586 Hz and JPHˆ21 Hz] via intramolecularly
cyclized intermediates 27c [dP (MeCN–C6D6)ˆ164 (br.
s)] and 28c [dP (MeCN–C6D6)ˆ164 (m)]. Thus, the cycli-
zation reaction is largely affected by the solvent.
As an alternative method, the phosphorus atom was intro-
duced by use of diethyl phosphorochloridite as a phosphorus
source. Thus, bromobenzenes 10a,b were lithiated with
butyllithium and the resulting phenyllithiums 24a,b were
allowed to react with diethyl phosphorochloridite to form
32a,b [32a: dP (THF–C6D6)ˆ170.9, 32b: dP (THF–
C6D6)ˆ168.2]. The reaction mixtures were worked up,
and ethyl phosphinates 33a,b were obtained in 63 and
45% yield, respectively, after column chromatographic
treatment. Phosphonous dichloride 26c and ethyl phosphi-
nate 33a,b were reduced with LiAlH4 in THF at 0ЊC, to form
the desired phosphines 34a–c (Scheme 7). Although phos-
phine 34a was isolated, attempted isolations of 34b,c have
been unsuccessful due to the oxidation reaction during the
isolation process.
Then, bromobenzenes 10a–c were lithiated with butyl-
lithium in THF under the conditions mentioned above,
and the resulting mixtures were allowed to react with PCl3
(Scheme 6). However, only 10c gave satisfactory results to
afford the corresponding phosphonous dichloride 26c. In the
cases of 10a,b, intramolecular cyclization of intermediary
phosphonous dichlorides 26a,b proceeded. Compounds
27a,b were observed by 31P NMR spectroscopic monitoring
during the reaction [27a: dP (THF–C6D6)ˆ166; 27b: dP
(THF–C6D6)ˆ156]. Intermediates 26a,b were not detected
by this monitoring, indicating that the cyclization reactions
are rapid. When compounds 27a,b were allowed to react
Chart 4.
Scheme 5.

46
M. Yoshifuji et al. / Tetrahedron 56 (2000) 43–55
Scheme 6.
Furthermore, phosphonous dichloride 26c was converted to
the corresponding diphosphene 35c by addition of lithium
naphthalenide. Although diphosphene 35c was formed as a
major product (indicated by 31P NMR spectrum of the reac-
tion mixture), the isolated yield of 35c was only 4% due to
the decomposition during the aluminum column-chromato-
graphic treatment. It should be noted that phosphonous
dichloride 26b reacted (before formation of 27b) with t-
butyllithium at Ϫ78ЊC to form diphosphene 35b (diphos-
phene 35b was decomposed during the isolation process).
Contrary to this, in the reaction of 26a with t-butyllithium at
Ϫ78ЊC, a signal due to diphosphene was not observed by 31P
NMR spectroscopic monitoring, probably because the cycli-
zation reaction of 26a to 27 was rapid.
Table 1. 31P NMR data for primary phosphines
Tables 1 and 2 show 31P NMR chemical shifts of phos-
phines 34a–c, diphosphenes 35b,c, and some related
compounds. The chemical shifts of 34a–c are very similar
to that of ArPH2 (34d) and considerably different from those
of (2,4-di-t-butyl-6-methylphenyl)phosphine (34e) and
MoxPH2 (34f). Similarly, the chemical shifts for 35b,c are
very close to that for diphosphene 1, probably because the
steric hindrance around the phosphorus atom plays an
R1
R2
d (JPH/Hz) in CDCl3
CMe2OMe
CMe2CH2OMe
CMe2OMe
CMe2CH2OMe
34a Ϫ129.1 (216.6)
34b Ϫ129.4 (209.3)
CMe2CH2CH2OMe CMe2CH2CH2OMe 34c Ϫ130.2 (209.2)
34d Ϫ129.9a (210.6)
34e Ϫ143.0b (203.0)
Table 2. 31P NMR data for diphosphenes
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
t-Bu
CH2NMe2
Me
OMe
NMe2
CH2NMe2
CMe2NMe2
CMe2CH2NMe2
CH2NMe2
34f
Ϫ155.4c (207.4)
Ϫ141.6d (213.7)
Ϫ143.6e (203.6)
Ϫ134.5f (206.8)
Ϫ127.4f (208)
Ϫ148.7g (207.4)
R1
R2
d in CDCl3
a Data taken from Ref. 15.
CMe2CH2OMe
CMe2CH2CH2OMe
t-Bu
CMe2CH2OMe
CMe2CH2CH2OMe
t-Bu
35b
35c
1
493.7
493.8
492.4a
428.2b
b Data reported in Ref. 16: Ϫ149.9 (JPHˆ201.1 Hz) in C6D6.
c Data taken from Ref. 6a, measured in C6D6.
d Data taken from Ref. 5a.
t-Bu
NMe2
e Data taken from Ref. 7.
f Data taken from Ref. 10.
a Data taken from Ref. 2, measured in C6D6.
b Data taken from Ref. 5a, measured in THF–C6D6.
g Data taken from Ref. 9.

M. Yoshifuji et al. / Tetrahedron 56 (2000) 43–55
47
Scheme 7.
Scheme 8.
important role in the chemical shift of these compounds and
electronic effects of the methoxy groups of 34a–c on the
chemical shift are relatively small.
The chemical shift for 37c is very close to that for ArPS2 (2)
[dP (CDCl3)ˆ298.2].3a
However, dithioxophosphorane 37c changed to compound
38c in the reaction mixture, which was isolated in 26% yield
after column chromatographic treatment. Similar results
were obtained in the case of the reaction of the phosphines
34a,b, giving 38a,b, although intermediary dithioxophos-
phoranes 37a,b were not observed by 31P NMR spectro-
scopic monitoring during the reaction.
Reaction of the phosphines with sulfur or selenium
We have reported that the sterically protected (2,4,6-tri-t-
butylphenyl)phosphine (ArPH2) reacted with elemental
sulfur in the presence of a base such as 1,8-diazabicyclo-
[5.4.0]undec-7-ene (DBU) to give dithioxophosphorane 2.3a
Thus, the reactions of phosphines 34a–c with elemental
sulfur were carried out in order to investigate the effect of
the methoxy groups on the phosphorus center in the
corresponding dithioxophosphoranes. When phosphine
34c was allowed to react with S8 in benzene in the presence
of a catalytic amount of DBU at room temperature, a signal
due to dithioxophosphorane 37c was observed (dPˆ295.2),
along with some signals of precursors such as phosphine
When phosphine 34c was allowed to react with elemental
selenium in benzene in the presence of a catalytic amount of
DBU at room temperature, a signal due to diselenoxophos-
phorane 40c was observed at dPˆ267.4, along with some
signals due to the precursors such as phosphine selenide 39c
[dPˆϪ52.3 (t, 1JPHˆ458 Hz), satellite d, 1JSePˆ736 Hz], by
31PNMR spectroscopy. The chemical shift for 40c was simi-
lar to that for ArPSe2 (3) [dP (CDCl3)ˆ273.0].4 However,
the reaction was complicated and the product isolated after
1
sulfide 36c [dPˆϪ25.0 (t, JPHˆ465 Hz)], by 31PNMR
spectroscopic monitoring during the reaction (Scheme 8).

48
M. Yoshifuji et al. / Tetrahedron 56 (2000) 43–55
column chromatography was 42c (11% yield based on 10c),
probably via intramolecular rearrangement of 40c to 41c
followed by oxidation of 41c during the isolation process
performed in the air.
2-Bromo-5-t-butylisophthalic acid (12)12b. To a mixture
of 2-bromo-5-t-butyl-1,3-dimethylbenzene (11, 4.51 g,
18.7 mmol),12a aqueous potassium hydroxide (113 mmol
of KOH in 45 mL of water), and pyridine (90 mL) was
added KMnO4 (31.1 g, 197 mmol) at 100ЊC over a 9-h
period. The resulting mixture was stirred for a further
11 h, then cooled to room temperature. An appropriate
amount of aqueous NaHSO3 was added to the reaction
mixture at 0ЊC, in order to consume unreacted KMnO4.
Then the resulting mixture was acidified with aqueous
H2SO4 to form colorless precipitates. The precipitates,
which consisted of 12 and half-oxidized compound 2-
bromo-5-t-butyl-3-methylbenzoic acid (43), were filtered
off and the filtrate was extracted with Et2O. The organic
phase was washed with saturated aqueous NaCl, dried
over MgSO4, then the solvent was removed under reduced
pressure to give 951.4 mg (17%) of 12.
In the reaction of phosphine 34a with selenium, formation
of 41a was observed as a major product by 31P NMR moni-
toring, however, 41a was isolated in very low yield (3%),
due to decomposition during the isolation procedure. When
34b was allowed to react with selenium under similar con-
ditions, the reaction became more complicated than the case
of 34a and only trace amount of 41b was obtained. In these
reactions of 34a,b, intermediary diselenoxophosphoranes
40a,b were not observed by 31P NMR spectroscopic moni-
toring during the reaction, and products of the 42c-type were
not isolated because of difficulties in separation from other
decomposition products.
1
Although the chemical shift of the dithioxophosphorane 37c
is similar to that of MoxPS2 (6) [dP (C6D6)ˆ277.6],6a 37 and
6 behave differently in reactivities. Compound 37 afforded a
rearranged compound rather than a dimeric compound.6a,b,17
In the case of 37, the methoxy group seems to interact with
the phosphorus atom more effectively than observed in 6,
due to the conformational flexibility. Because sulfur is more
electronegative than phosphorus, the phosphorus atom in
the –P(yS)2 moiety has a partially cationic character. In
the case of dithioxophosphoranes bearing aniline-type
ligands such as MxPS2 (4), this cationic character causes
intramolecular coordination of the nitrogen atom as shown
in Chart 1. When the oxygen atom in 37 coordinates to the
phosphorus atom, the carbon atom of the methoxy group
may become positive to be attacked by the sulfur atom
of the –P(yS)2 moiety. The situation in the diselenoxo-
phosphorane 40 seems to be similar.
12: Colorless prisms, mp 260–262ЊC (AcOEt); H NMR
(200 MHz, CD3OD) d 1.34 (9H, s, t-Bu) and 7.75 (2H, s,
arom.); 13C{1H} NMR (50 MHz, CD3OD) d 32.1 (CMe3),
36.5 (CMe3), 116.2 (arom., CBr), 130.7 (arom., CH), 138.4
(arom.), 153.1 (arom.), and 171.1 (CyO); IR (KBr) 3600–
2500 (br.), 2968, 1722, 1699, 1402, 1248, 1225, 908, and
688 cmϪ1; MS (70 eV) m/z (rel intensity) 302 (Mϩϩ2; 21),
300 (Mϩ; 22), 287 (MϩϪMeϩ2; 99), and 285 (MϩϪMe;
100). Found: m/z 299.9994. Calcd for C12H13BrO4: M,
299.9997.
1
43: Colorless prisms, mp 182–183ЊC (AcOEt); H NMR
(200 MHz, CDCl3) d 1.33 (9H, s, t-Bu), 2.49 (3H, s, Me),
4
4
7.43 (1H, d, Jˆ2.5 Hz, arom.), 7.74 (1H, d, Jˆ2.5 Hz,
arom.), and 9.4–10.3 (1H, br. s, OH); 13C{1H} NMR
(50 MHz, CDCl3) d 24.1 (Me), 31.0 (CMe3), 34.5 (CMe3),
120.6 (arom., CBr), 126.4 (arom., CH), 131.5 (arom.), 131.6
(arom., CH), 139.5 (arom.), 150.0 (arom.), and 172.9
(CyO); IR (KBr) 3200–2200 (br.), 2968, 1701, 1684,
1585, 1460, 1425, 1311, 1284, 1248, 1192, 1032, 937,
887, 715, and 644 cmϪ1; MS (70 eV) m/z (rel intensity)
272 (Mϩϩ2; 23), 270 (Mϩ; 24), 257 (MϩϪMeϩ2; 100),
and 255 (MϩϪMe; 100).
In conclusion, interaction between the methoxy group and
the phosphorus atom is relatively small in the primary
phosphine 34 and diphosphene 35, while there is a large
interaction in the dithioxophosphoranes 37 and diselenoxo-
phosphoranes 40. This interaction causes methyl-group
migration in 37 and 40, to give the cyclized products 38
and 41, respectively. Thus, benzene-fused five- to seven-
membered ring heterocyclic compounds (29, 38, 41, and
42) containing the endo-cyclic phosphorus–oxygen bond
were obtained in this study. Detailed mechanistic studies
of the sulfurization reaction and the selenation reaction, as
well as studies on properties of the heterocycles, are in
progress.
Dimethyl 2-bromo-5-t-butylisophthalate (13). A mixture
of 12 (5.19 g), methanol (50 mL), sulfuric acid (5 mL) was
heated under reflux for 3 h and then cooled to room
temperature. The reaction mixture was poured into
200 mL of water and the resulting suspension was neutra-
lized by addition of solid NaHCO3. Then the mixture was
extracted with ether and the combined organic phase was
dried over MgSO4. The solvent was removed in vacuo and
the residue was recrystallized from hexane to give 13
(3.43 g, 60%).
Experimental
1
13: Colorless plates, mp 100–101ЊC (hexane); H NMR
Melting points were measured on a Yanagimoto MP-J3
micro melting points apparatus and were uncorrected. H
1
(200 MHz, CDCl3) d 1.32 (9H, s, t-Bu), 3.95 (6H, s,
OMe), and 7.69 (2H, s, arom.); 13C{1H} NMR (50 MHz,
CDCl3) d 30.8 (CMe3), 34.7 (CMe3), 52.6 (OMe), 115.6
(arom., CBr), 129.4 (arom., CH), 134.9 (arom.), 150.7
(arom.), and 167.3 (CyO); IR (KBr) 1734, 1716, 1475,
1442, 1433, 1365, 1338, 1292, 1267, 1254, 1216, 1196,
(200 MHz) and 31P (81 MHz) NMR spectra were taken on a
Bruker AC-200P spectrometer. UV–Vis spectra were
obtained on a Hitachi U-3210 spectrometer. IR spectra
were recorded on a Horiba FT-300 spectrometer and mass
spectra were taken on a JEOL HX-110 spectrometer. All
experiments, except for the work-up and chromatographic
treatment, were carried out under argon with anhydrous and
deoxygenated solvents unless otherwise noted.
1177, 1155, 984, 968, 877, 795, 715, and 647 cmϪ1
;
MS (70 eV) m/z (rel intensity) 330 (Mϩϩ2; 20), 328 (Mϩ;
20), 315 (MϩϪMeϩ2; 100), and 313 (MϩϪMe; 100).

M. Yoshifuji et al. / Tetrahedron 56 (2000) 43–55
49
Found: m/z 328.0301. Calcd for C14H17BrO4: M,
328.0310.
recrystallized from ethanol to give 11.0 g (89% yield) of
16.
1
2-Bromo-5-t-butyl-1,3-bis(1-hydroxy-1-methylethyl)-
benzene (14). To a solution of 13 (299.8 mg, 0.911 mmol)
in THF (15 mL) was added 9.3 mmol of methylmagnesium
bromide (0.93M in THF) at 0ЊC. The resulting mixture was
stirred at ambient temperature for 18 h. The reaction was
quenched by addition of aqueous NH4Cl at 0ЊC. Then the
resulting suspension was extracted using ether and saturated
aqueous NaHCO3 and the organic phase was dried over
MgSO4. Removal of the solvent under reduced pressure
followed by chromatographic treatment (SiO2/CHCl3)
afforded 193.1 mg (64%) of 14.
16: Colorless needles, mp 145–146ЊC (EtOH); H NMR
(200 MHz, CDCl3) d 1.35 (9H, s, t-Bu), 3.87 (4H, s,
CH2), and 7.51 (2H, s, arom.); 13C{1H} NMR (50 MHz,
CDCl3) d 25.7 (CH2), 31.0 (CMe3), 34.9 (CMe3), 116.7
(CN), 121.6 (arom., CBr), 127.0 (arom., CH), 130.8
(arom.), and 152.2 (arom.); UV (CH3CN) 220 (sh, log e
3.99), 235 (sh, 3.67), 261 (sh, 2.47), 268 (2.57), and
280 nm (sh, 2.24); IR (KBr) 2254, 1481, 1458, 1412,
1363, 1149, 1028, and 889 cmϪ1; MS (70 eV) m/z (rel inten-
sity) 292 (Mϩϩ2; 13), 290 (Mϩ; 15), 277 (MϩϪMeϩ2;
100), and 275 (MϩϪMe; 99). Found: C, 57.50; H, 5.49;
Br, 27.20; N, 9.47%. Calcd for C14H15BrN2: C, 57.75; H,
5.19; Br, 27.44; N, 9.62%.
14: Colorless crystals, mp 135–137ЊC; 1H NMR (200 MHz,
CDCl3) d 1.32 (9H, s, t-Bu), 1.81 (12H, s, CMe2), 3.06 (2H,
br. s, OH), and 7.66 (2H, s, arom.); 13C{1H} NMR (50 MHz,
CDCl3) d 30.2 (CMe3), 31.2 (CMe2O), 34.9 (CMe3), 74.8
(CMe2O), 116.6 (arom., CBr), 123.9 (arom., CH), 146.6
(arom.), and 149.9 (arom.); IR (KBr) 3334, 3018, 2929,
2870, 1477, 1458, 1400, 1362, 1255, 1213, 1178, 1136,
1011, 956, 901, 760, and 737 cmϪ1; MS (70 eV) m/z (rel
intensity) 330 (Mϩϩ2; 14), 328 (Mϩ; 14), 315
(MϩϪMeϩ2; 96), 313 (MϩϪMe; 100), 297
(MϩϪ2OHϩ3; 24), 295 (MϩϪ2OHϩ1; 21), and 57
(t-Buϩ; 44). Found: m/z 328.1041. Calcd for C16H25BrO2:
M, 328.1038.
2-Bromo-5-t-butyl-1,3-bis(1-cyano-1-methylethyl)benzene
(17). To a solution of 16 (5.10 g, 17.5 mmol) in dimethyl
sulfoxide (50 mL) was added 1.0 mL of water and 14.1 g
(251 mmol) of powdered KOH. The resulting dark solution
was cooled using an ice-bath and 15.0 mL (240 mmol) of
iodomethane was added. Then the mixture was warmed to
room temperature and stirred for 41 h. The reaction mixture
was extracted with ether, washed with saturated aqueous
NaCl, and then the organic layer was dried over MgSO4.
The solvent was removed under reduced pressure and the
residue was treated with column chromatography (SiO2/
CHCl3) to give 3.96 g (65%) of 17.
2-Bromo-5-t-butyl-1,3-bis(1-methoxy-1-methylethyl)-
benzene (10a). A solution of 14 (1.34 g, 4.07 mmol) in THF
(50 mL) was added to ca. 25 mmol of NaH at 0ЊC over a
5-min period. The resulting mixture was stirred at 0ЊC for
5 min, and 24.1 mmol of iodomethane was added. The
reaction mixture was warmed to room temperature and
stirred for 21 h. The reaction was quenched by addition of
methanol and the solvent was removed in vacuo. The
residue was worked up using hexane and aqueous Na2SO3
and the organic phase was dried over MgSO4. Removal of
the solvent gave 1.33 g (92%) of 10a.
1
17: Colorless fine needles, mp 222–222.5ЊC (EtOH); H
NMR (200 MHz, CDCl3) d 1.33 (9H, s, t-Bu), 1.94 (12H,
s, CMe2), and 7.48 (2H, s, arom.); 13C{1H} NMR
(50 MHz, CDCl3) d 28.3 (CMe2), 31.1 (CMe3), 35.1
(CMe3), 38.3 (CMe2), 120.8 (arom., CBr), 123.5 (CN),
124.3 (arom., CH), 140.0 (arom.), and 150.9 (arom.);
UV (hexane) 224 (sh, log e 3.59), 228 (3.58), 234 (sh,
3.53), 269 (2.22), and 278 nm (2.10); IR (KBr) 2231,
1415, 1371, 1020, and 739 cmϪ1; MS (70 eV) m/z (rel
intensity) 348 (Mϩϩ2; 18), 346 (Mϩ; 18), 333
(MϩϪMeϩ2; 100), 331 (MϩϪMe; 100), and 57 (t-Buϩ;
30). Found: m/z 346.1056. Calcd for C18H23BrN2: M,
346.1044.
1
10a: Colorless crystals, mp 62–65ЊC; H NMR (200 MHz,
CDCl3) d 1.32 (9H, s, t-Bu), 1.76 (12H, s, CMe2), 3.12 (6H,
s, OMe), and 7.43 (2H, s, arom.); 13C{1H} NMR (50 MHz,
CDCl3) d 27.5 (CMe2O), 31.2 (CMe3), 34.6 (CMe3), 50.5
(OMe), 79.6 (CMe2O), 117.9 (arom., CBr), 125.3 (arom.,
CH), 143.8 (arom.), and 148.9 (arom.); IR (KBr) 1477,
1396, 1375, 1360, 1171, 1068, 1012, 879, 850, and
748 cmϪ1; MS (70 eV) m/z (rel intensity) 358 (Mϩϩ2;
11), 356 (Mϩ; 11), 343 (MϩϪMeϩ2; 100), 341
(MϩϪMe; 99), 247 (MϩϪBr–OMeϩ1; 27), 72
(CMe2OMeϩ; 55), and 57 (t-Buϩ; 17). Found: m/z
356.1354. Calcd for C18H29BrO2: M, 356.1351.
2-Bromo-5-t-butyl-1,3-bis(1-formyl-1-methylethyl)benzene
(18). To a solution of 17 (4.24 g, 12.2 mmol) in benzene
(260 mL) was added 30.3 mmol of diisobutylaluminum
hydride (1.01 M solution in toluene) and the resulting
mixture was stirred at ambient temperature for 4 h. The
resulting mixture was cooled using an ice-bath and 5%
aqueous sulfuric acid was added to the mixture. After
being stirred for 20 min, the reaction mixture was worked
up using benzene and saturated aqueous NaCl. The organic
layer was dried over MgSO4, and the solvent was removed
under reduced pressure to give 18 (4.29 g, 99% yield).
2-Bromo-5-t-butyl-1,3-bis(cyanomethyl)benzene (16). To
a mixture of 2-bromo-1,3-bis(bromomethyl)-5-t-butylben-
zene (15, 17.0 g, 42.5 mmol)13 and 18-crown-6 (2.92 g,
11.0 mmol) in acetonitrile (200 mL) was added potassium
cyanide (8.16 g, 125 mmol) and water (33 mL), then the
resulting mixture was refluxed for 3.5 h. The reaction
mixture was extracted with ether and saturated aqueous
NaCl, and then the organic layer was dried over MgSO4.
The solvent was removed in vacuo and the residue was
18: Colorless powder, mp 142.5–145.0ЊC; 1H NMR
(200 MHz, CDCl3) d 1.36 (9H, s, t-Bu), 1.53 (12H, s,
CMe2), 7.42 (2H, s, arom.), and 9.78 (2H, s, CHO);
13C{1H} NMR (50 MHz, CDCl3) d 23.8 (CMe2), 31.2
(CMe3), 35.0 (CMe3), 52.7 (CMe2), 121.6 (arom., CBr),
125.3 (arom., CH), 143.5 (arom.), 150.9 (arom.), and
203.0 (CHO); UV (hexane) 223 (sh, log e 4.02), 232

50
M. Yoshifuji et al. / Tetrahedron 56 (2000) 43–55
(3.79), 267 (2.54), 280 (2.39), and 306 nm (2.07); IR
(KBr) 2962, 2803, 2705, 1722, 1587, 1469, 1389, and
1016 cmϪ1; MS (70 eV) m/z (rel intensity) 352 (Mϩ; 0.2),
323 (MϩϪCHO; 5), 273 (MϩϪBr; 37), and 57 (t-Buϩ;
100).
15% yield, indicating that the second methylation
proceeded slowly.
10b: Colorless oil; 1H NMR (200 MHz, CDCl3) d 1.33 (9H,
s, t-Bu), 1.58 (12H, s, CMe2), 3.35 (6H, s, OMe), 3.79 (4H,
s, CH2), and 7.37 (2H, s, arom.); 13C{1H} NMR (50 MHz,
CDCl3) d 26.2 (CMe2), 31.3 (CMe3), 34.6 (CMe3), 42.7
(CMe2), 59.0 (s, OMe), 81.1 (CH2), 121.3 (arom., CBr),
125.5 (arom., CH), 145.4 (arom.), and 148.2 (arom.); UV
(hexane) 233 nm (sh, log e 3.90); IR (neat) 1590, 1479,
2-Bromo-5-t-butyl-1,3-bis(2-hydroxy-1,1-dimethylethyl)-
benzene (19). A THF (80 mL) solution of 18 (1.61 g,
4.50 mmol) was added dropwise to a suspension of
LiAlH4 (473 mg, 12.5 mmol) in THF (10 mL) at 0ЊC.
Then the resulting mixture was stirred at room temperature
for 1.5 h and treated with MeOH. The reaction mixture was
extracted with ether, washed with saturated aqueous NaCl,
and then the organic layer was dried over MgSO4. The
solvent was removed in vacuo, then the residue was treated
with column chromatography (SiO2/CHCl3–Et2O) to afford
1.10 g (68%) of 19.
1462, 1392, 1363, 1198, 1109, 1012, 966, and 736 cmϪ1
;
MS (70 eV) m/z (rel intensity) 339 (MϩϪCH2OMe; 12),
305 (MϩϪBr; 28), 245 (MϩϪBr–2OMeϩ2; 9), and 57 (t-
Buϩ; 100) (molecular ion peak was not observed in the mass
spectrum).
20: Colorless oil; 1H NMR (200 MHz, CDCl3) d 1.32 (9H, s,
t-Bu), 1.57 (12H, s, CMe2), 3.35 (3H, s, OMe), 3.78 (2H, s,
CH2OMe), 4.10 (2H, s, CH2OH), 7.40 (1H, d, 4JHHˆ2.5 Hz,
19: Colorless powder, mp 210.5–213.5ЊC (hexane); 1H
NMR (200 MHz, CDCl3) d 1.32 (9H, s, t-Bu), 1.42 (2H,
br. s, OH), 1.57 (12H, s, CMe2), 4.10 (4H, s, CH2), and 7.45
(2H, s, arom.); 13C{1H} NMR (50 MHz, CDCl3) d 26.7
(CMe2), 31.2 (CMe3), 34.9 (CMe3), 44.0 (CMe2), 69.9
(CH2), 120.8 (arom., CBr), 126.5 (arom., CH), 144.4
(arom.), and 148.7 (arom.); UV (CH2Cl2) 235 nm (sh,
log e 3.74); IR (KBr) 3330, 2958, 2881, 1475, 1411,
1394, 1363, and 1031 cmϪ1; MS (70 eV) m/z (rel intensity)
307 (MϩϪMe–2OH; 10), 276 (MϩϪBrϪ1; 5), 267
(MϩϪt-Bu–2OH; 7), 259 (MϩϪBr–OHϪ1; 27), 245
(MϩϪBr–2OH; 55), and 57 (t-Buϩ; 100) (molecular ion
peak was not observed in the mass spectrum).
4
arom.), and 7.41 (1H, d, JHHˆ2.5 Hz, arom.); 13C{1H}
NMR (50 MHz, CDCl3) d 26.3 (CMe2CH2OH), 26.7
(CMe2CH2OMe), 31.3 (CMe3), 34.8 (CMe3), 42.7
(CMe2CH2OH), 44.0 (CMe2CH2OMe), 59.0 (s, OMe),
70.0 (CH2OH), 81.1 (CH2OMe), 121.0 (arom., CBr),
125.9 (arom., CH), 126.2 (arom., CH), 144.2 (arom.)
145.6 (arom.), and 148.5 (arom.); UV (hexane) 235 nm
(sh, log e 3.62); IR (neat) 3432, 2964, 2873, 1590, 1477,
1461, 1392, 1363, 1108, 1041, 1012, 879, and 736 cmϪ1
;
MS (70 eV) m/z (rel intensity) 339 (MϩϪOMe; 2), 291
(MϩϪBr; 3), 259 (MϩϪBr–OMeϪ1; 45), 245 (MϩϪBr–
OMe–OHϩ2; 67), and 57 (t-Buϩ; 100) (molecular ion peak
was not observed in the mass spectrum).
2-Bromo-5-t-butyl-1,3-bis(2-methoxy-1,1-dimethylethyl)-
benzene (10b). Method A: A THF (25 mL) solution of 19
(1.12 g, 3.14 mmol) was added to ca. 9.9 mmol of sodium
hydride at 0ЊC and the resulting mixture was stirred for
15 min at 0ЊC. To this suspension was added 1.2 mL
(19 mmol) of iodomethane at 0ЊC and the reaction mixture
was stirred for 6 h at ambient temperature. Then the mixture
was treated with methanol and the solvent was evaporated.
The residue was worked up using hexane and aqueous
NaHSO4, and the organic layer was dried over MgSO4.
The solvent was removed under reduced pressure to give
1.13 g (93%) of 10b.
2-Bromo-5-t-butyl-1,3-bis(1,1-dimethyl-2-propenyl)ben-
zene (21). To a solution of methyltriphenylphosphonium
bromide (7.80 g, 21.8 mmol) in THF (60 mL) was added
22.0 mmol of sodium bis(trimethylsilyl)amide (1.00 M
solution in THF) and the resulting mixture was heated to
reflux for 3 h. Then the reaction mixture was cooled to room
temperature, and to this mixture was added a THF (50 mL)
solution of 18. The resulting mixture was stirred at ambient
temperature for 2 h. Then the reaction was quenched by
addition of water. The mixture was extracted with ether
and the organic phase was dried over MgSO4, and the
solvent was removed in vacuo. The residue was treated
with column chromatography (SiO2/hexane–CHCl3) to
give 2.03 g (91%) of 21.
Method B: To a solution of 19 (180.3 mg, 0.505 mmol) and
benzyltriethylammonium chloride (3.2 mg, 0.014 mmol) in
benzene (45 mL) was added 50% aqueous NaOH (2.0 mL)
and the reaction mixture was vigorously stirred for 30 min.
Then the mixture was cooled over an ice-bath and 1.15 mL
(12.1 mmol) of dimethyl sulfate was added. After being
stirred for 6 h, the reaction mixture was treated with 29%
aqueous ammonia, and the resulting mixture was stirred at
room temperature for 30 min. Then the mixture was
extracted with benzene, the organic phase was dried over
MgSO4, and the solvent was removed in vacuo. The
residue was treated with column chromatography (SiO2/
CHCl3) to give 6.4 mg (3%) of 10b, 110.3 mg (59%) of
2-bromo-5-t-butyl-1-(2-hydroxy-1,1-dimethylethyl)-3-(2-
methoxy-1,1-dimethylethyl)benzene (20), and 49.2 mg
(27% recovery) of the starting 19. Attempted reaction of
the isolated 20 with dimethyl sulfate under similar con-
ditions with longer reaction time (1 day) gave 10b in only
1
21: Colorless oil; H NMR (200 MHz, CDCl3) d 1.34 (9H,
s, t-Bu), 1.60 (12H, s, CMe2), 4.91 (2H, dd, 3Jˆ17.6 Hz and
2Jˆ0.8 Hz, CH2), 5.00 (2H, dd, 3Jˆ10.6 Hz and 2Jˆ0.8 Hz,
CH2), 6.24 (2H, dd, 3Jˆ17.6 Hz and 3Jˆ10.6 Hz,
CHyCH2), and 7.43 (2H, s, arom.); 13C{1H} NMR
(50 MHz, CDCl3) d 29.7 (CMe2), 31.3 (CMe3), 34.9
(CMe3), 44.1 (CMe2), 110.7 (CH2), 122.4 (arom., CBr),
124.0 (arom., CH), 147.6 (arom.), 148.5 (arom.), and
148.8 (CHyCH2); UV (hexane) 240 (log e 3.62) and
266 nm (2.47); IR (neat) 3082, 2966, 1633, 1465, 1408,
1362, 1173, 1016, 989, 903, 879, 742, and 676 cmϪ1; MS
(70 eV) m/z (rel intensity) 350 (Mϩϩ2; 39), 348 (Mϩ; 38),
335 (MϩϪMeϩ2; 49), 333 (MϩϪMe; 48), and 57 (t-Buϩ;
100). Found: m/z 348.1455. Calcd for C20H29Br: M,
348.1453.

M. Yoshifuji et al. / Tetrahedron 56 (2000) 43–55
51
2-Bromo-5-t-butyl-1,3-bis(3-hydroxy-1,1-dimethylpropyl)-
benzene (22). To a THF (25 mL) solution of 21 (199 mg,
0.570 mmol) was added 3.40 mmol of borane–THF
complex (1.0 M solution in THF) at 0ЊC, and the reaction
mixture was stirred at room temperature for 45 min. The
resulting solution was cooled to 0ЊC, and the reaction
was quenched by addition of water. Aqueous NaOH
(5.46 mmol), 30% aqueous hydrogen peroxide (5.3 mmol)
were added successively to the reaction mixture at 0ЊC, and
the resulting mixture was stirred at room temperature for
3 h. Then the reaction mixture was extracted with ether, the
organic phase was dried over MgSO4, and the solvent was
removed under reduced pressure. The residue was treated
with column chromatography (SiO2/Et2O) to give 157.6 mg
(72%) of 22 and 52.8 mg (24%) of 2-bromo-5-t-butyl-1-(2-
hydroxy-1,1-dimethylpropyl)-3-(3-hydroxy-1,1-dimethyl-
propyl)benzene (23).
residue was extracted with hexane. The organic phase was
dried over MgSO4, and the solvent was removed to give
2.16 g (99%) of 10c.
1
10c: Colorless crystals, mp 42–43ЊC; H NMR (200 MHz,
CDCl3) d 1.31 (9H, s, t-Bu), 1.58 (12H, s, CMe2), 2.40 (4H,
3
3
t, Jˆ7.5 Hz, CH2CH2O), 3.11 (4H, t, Jˆ7.5 Hz, CH2O),
3.19 (6H, s, OMe), and 7.33 (2H, s, arom.); 13C{1H} NMR
(50 MHz, CDCl3) d 30.4 (CMe2), 31.2 (CMe3), 34.8
(CMe3), 39.4 (CH2CH2O), 40.3 (CMe2), 58.4 (OMe), 70.5
(CH2O), 121.6 (arom., CBr), 124.8 (arom., CH), 146.1
(arom.), and 148.3 (arom.); IR (neat) 1589, 1477, 1462,
1387, 1363, 1205, 1119, 1012, 966, and 879 cmϪ1; MS
(70 eV) m/z (rel intensity) 414 (Mϩϩ2; 0.4), 412 (Mϩ;
0.4), 275 (MϩϪBr–t-BuϪ1; 52), 243 (MϩϪBr–t-Bu–
OMeϪ2; 81), and 57 (t-Buϩ; 100). Found: m/z 412.1981.
Calcd for C22H37BrO2: M, 412.1977.
1
22: Colorless plates, mp 123–125ЊC; H NMR (200 MHz,
General procedure for the lithiation of the bromo-
benzenes 10a–c. To a solution of 10 (0.08 mmol) in
THF (3 mL) was added 0.09 mmol of butyllithium
(1.54M in hexane) at room temperature (for 10a,b) or
at Ϫ78ЊC (for 10c) and the resulting mixture was further
stirred at those temperatures for 20 min. Then the reac-
tion was quenched by addition of water. The reaction
mixture was extracted using ether and the organic phase
was dried over MgSO4. Removal of the solvent afforded
25.
CDCl3) d 1.30 (9H, s, t-Bu), 1.39 (2H, br. s, OH), 1.58 (12H,
3
s, CMe2), 2.42 (4H, t, Jˆ7.5 Hz, CH2CH2O), 3.41 (4H, t,
3Jˆ7.5 Hz, CH2O), and 7.33 (2H, s, arom.); 13C{1H} NMR
(50 MHz, CDCl3) d 30.5 (CMe2), 31.2 (CMe3), 34.8
(CMe3), 40.3 (CMe2), 42.5 (CH2CH2O), 60.4 (CH2O),
121.5 (arom., CBr), 124.8 (arom., CH), 146.1 (arom.), and
148.7 (arom.); IR (neat) 3292, 2960, 2927, 2871, 1591,
1479, 1463, 1404, 1385, 1363, 1061, 1039, 1028, 1014,
985, 879, 775, and 740 cmϪ1; MS (70 eV) m/z (rel intensity)
339 (MϩϪCH2CH2OH; 0.3), 259 (MϩϪBr–CH2
CH2OHϪ1; 17), 219 (MϩϪBr–CMe2CH2CH2OHϩ1; 42),
and 57 (t-Buϩ; 100) (molecular ion peak was not observed
in the mass spectrum). Found: C, 62.55; H, 8.57%. Calcd for
C20H33BrO2: C, 62.33; H, 8.63%.
25a (96% yield): Colorless oil; 1H NMR (200 MHz, CDCl3)
d 1.34 (9H, s, t-Bu), 1.54 (12H, s, CMe2), 3.07 (6H, s,
4
OMe), 7.24 (1H, t, Jˆ1.6 Hz, arom.), and 7.32 (2H, d,
4Jˆ1.6 Hz, arom.); 13C{1H} NMR (50 MHz, CDCl3) d
28.1 (CMe2), 31.5 (CMe3), 34.8 (CMe3), 50.5 (OMe), 77.1
(CMe2), 120.3 (arom., CH), 121.1 (arom., CH), 145.1
(arom.), and 150.7 (arom.); IR (neat) 1599, 1462, 1435,
1377, 1362, 1242, 1173, 1076, 877, 816, 760, and
719 cmϪ1; MS (70 eV) m/z (rel intensity) 278 (Mϩ; 3),
263 (MϩϪMe; 100), and 247 (MϩϪOMe; 10). Found:
m/z 278.2246. Calcd for C18H30O2: M, 278.2246.
23: Colorless crystals, mp 148–149ЊC; 1H NMR (200 MHz,
3
CDCl3) d 1.06 (3H, d, Jˆ6.4 Hz, CHMe), 1.30 (9H, s,
t-Bu), 1.54 (3H, s, CMe2), 1.57 (3H, s, CMe2), 1.58 (6H,
s, CMe2), 2.33-2.49 (2H, m, CH2CH2O), 3.41 (2H, t,
3Jˆ7.5 Hz, CH2O), 5.20 (1H, q, Jˆ6.4 Hz, CHMe), 7.35
3
4
4
(1H, d, Jˆ2.4 Hz, arom.), and 7.40 (1H, d, Jˆ2.4 Hz,
arom.); 13C{1H} NMR (50 MHz, CDCl3) d 17.6 (CHMe),
24.4 (CMe2), 30.4 (CMe2), 30.6 (CMe2), 31.2 (CMe3), 34.8
(CMe3), 40.2 (CMe2CH2), 42.6 (CH2CH2O), 46.6
(CMe2CO), 60.6 (CH2O), 69.4 (CHMe), 120.9 (arom.,
CBr), 125.1 (arom., CH), 126.0 (arom., CH), 145.9
(arom.), 146.4 (arom.), and 148.6 (arom.); IR (neat) 3325,
2966, 2929, 2879, 1475, 1458, 1412, 1402, 1392, 1362,
1311, 1149, 1095, 1068, 1059, 1030, 1012, 901, 881, 744,
and 636 cmϪ1; MS (70 eV) m/z (rel intensity) 368
(MϩϪOHϩ1; 0.3), 366 (MϩϪOHϪ1; 0.3), 341
(MϩϪCH(OH)Meϩ2; 3), 339 (MϩϪCH(OH)Me; 2), and
261 (MϩϪCH(OH)Me–Br; 100) (molecular ion peak was
not observed in the mass spectrum).
25b (92% yield): Colorless oil; 1H NMR (200 MHz, CDCl3)
d 1.33 (9H, s, t-Bu), 1.34 (12H, s, CMe2), 3.33 (6H, s,
4
OMe), 3.40 (4H, s, CH2), 7.22 (1H, t, Jˆ1.7 Hz, arom.),
and 7.30 (2H, d, 4Jˆ1.7 Hz, arom.); 13C{1H} NMR
(50 MHz, CDCl3) d 26.1 (CMe2), 31.5 (CMe3), 34.9
(CMe3), 39.3 (CMe2), 59.3 (OMe), 82.9 (CH2), 120.6
(arom., CH), 120.7 (arom., CH), 146.4 (arom.), and 149.9
(arom.); IR (neat) 1597, 1477, 1456, 1362, 1194, 1111, 964,
874, and 714 cmϪ1; MS (70 eV) m/z (rel intensity) 306 (Mϩ;
8), 261 (MϩϪCH2OMe; 100), 215 (MϩϪ2CH2OMeϪ1;
11), and 57 (t-Buϩ; 11). Found: m/z 306.2558. Calcd for
C20H34O2: M, 306.2559.
2-Bromo-5-t-butyl-1,3-bis(3-methoxy-1,1-dimethylpropyl)-
benzene (10c). A THF (100 mL) solution of 22 (2.02 g,
5.24 mmol) was added to sodium hydride (31 mmol) at
0ЊC over a 15-min period. The resulting mixture was stirred
at 0ЊC for 5 min, and to this mixture was added 32.1 mmol
of iodomethane at 0ЊC. The reaction mixture was warmed to
room temperature and stirred for 72 h. Appropriate amount
of methanol was added to the mixture in order to quench the
unreacted NaH. Then the solvent was evaporated and the
25c (97% yield): Colorless oil; 1H NMR (200 MHz, CDCl3)
d 1.33 (9H, s, t-Bu), 1.35 (12H, s, CMe2), 1.94 (4H, t,
3Jˆ7.8 Hz, CH2CH2O), 3.20 (4H, t, 3Jˆ7.8 Hz, CH2O),
4
3.24 (6H, s, OMe), 7.14 (1H, t, Jˆ1.7 Hz, arom.), and
4
7.20 (2H, d, Jˆ1.7 Hz, arom.); 13C{1H} NMR (50 MHz,
CDCl3) d 29.3 (CMe2), 31.5 (CMe3), 34.9 (CMe3), 36.8
(CMe2), 43.4 (CH2CH2O), 58.4 (OMe), 70.1 (CH2O),
119.8 (arom., CH), 120.1 (arom., CH), 147.8 (arom.), and
150.1 (arom.); IR (neat) 1597, 1460, 1363, 1117, and

52
M. Yoshifuji et al. / Tetrahedron 56 (2000) 43–55
715 cmϪ1; MS (70 eV) m/z (rel intensity) 334 (Mϩ; 20) and
276 (MϩϪt-BuϩϪ1; 100). Found: m/z 334.2865. Calcd for
C22H38O2: M, 334.2872.
1365, 1238, 1232, 1106, 1010, 941, 821, and 756 cmϪ1
;
MS (70 eV) m/z (rel intensity) 338 (Mϩ; 6), 323
(MϩϪMe; 11), 306 (MϩϪOMeϪ1; 5), 293
(MϩϪCH2OMe; 31), and 57 (t-Buϩ; 100). Found: m/z
338.2012. Calcd for C19H31O3P: M, 338.2011.
Attempted preparation of the phosphonous dichlorides
26a,b. To a solution of bromobenzene 10a (39.4 mg,
0.110 mmol) in THF (4 mL) was added 0.123 mmol of
butyllithium at room temperature and the resulting solution
was stirred for 10 min. The solution was cooled to 0ЊC and
0.287 mmol of PCl3 was added. Then the reaction mixture
was warmed to room temperature. Formation of the cyclized
product 27a was observed by 31P NMR spectroscopy. To this
solution was added 1.0 mL of methanol at room temperature
and the solvent was evaporated. The residue was worked
up with hexane and saturated aqueous NaCl, the organic
phase was dried over MgSO4, and the solvent was
removed in vacuo. Chromatographic treatment of the
residue afforded 8.3 mg (24%) of 5-t-butyl-3,3-dimethyl-
7-(1-methoxy-1-methylethyl)-2-oxa-1-phosphaindan 1-oxide
(29a). Similarly, 6-t-butyl-4,4-dimethyl-8-(2-methoxy-1,1-
dimethylethyl)-2-oxa-1-phospha-1,2,3,4-tetrahydronaphth-
alene 1-oxide (29b) was obtained from 10b in 41% yield.
Formation of [4-t-Butyl-2,6-bis(3-methoxy-1,1-dimethyl-
propyl)phenyl]phosphonous dichloride (26c). To
a
solution of 10c (33.6 mg, 0.0813 mmol) in THF (5 mL)
was added 0.0882 mmol of butyllithium (1.47 M in hexane)
at Ϫ78ЊC, and the resulting solution was stirred at that
temperature for 20 min. Phosphorus trichloride
(0.138 mmol) was added to the solution and the resulting
mixture was stirred at Ϫ78ЊC for 20 min. Aliquots of the
reaction mixture were occasionally removed and analyzed
by 31P NMR spectroscopy and a signal due to 26c [dP (THF–
C6D6)ˆ152.7] was observed as a single product. The
reaction mixture was stirred for an additional hour. Triethyl-
amine (0.10 mL) and methanol (0.80 mL) were added to the
solution and the resulting mixture was warmed to room
temperature. 31P NMR spectrum of the reaction mixture
indicated the formation of 30. The solvent was removed
in vacuo and the residue was worked up using ether and
saturated aqueous NaCl, dried over MgSO4, and the
solvent was evaporated. Chromatographic treatment of
the residue afforded 13.9 mg (39%) of dimethyl [4-t-butyl-
2,6-bis(3-methoxy-1,1-dimethylpropyl)phenyl]phosphonate
(31).
29a: Colorless crystals, mp 139–142ЊC; 1H NMR
(200 MHz, CDCl3) d 1.35 (9H, s, t-Bu), 1.60 (3H, s,
CMe2OP), 1.61 (6H, s, CMe2OMe), 1.75 (3H, s,
4
CMe2OP), 3.43 (3H, s, OMe), 7.13 (1H, pseudo-t, JPHˆ
4
4JHHˆ1.5 Hz, arom.), 7.29 (1H, dd, JPHˆ5.5 Hz,
1
4JHHˆ1.5 Hz, arom.), and 7.96 (1H, d, JPHˆ631.8 Hz,
PH); 13C{1H} NMR (50 MHz, CDCl3) d 24.1 (s, CMe2),
28.6 (s, CMe2), 30.5 (d, JPCˆ4.0 Hz, CMe2), 31.1 (s,
CMe2), 31.2 (s, CMe3), 35.3 (d, JPCˆ0.7 Hz, CMe3), 49.4
(s, OMe), 77.8 (d, JPCˆ1.0 Hz, CMe2), 87.0 (d, JPCˆ0.8 Hz,
CMe2), 116.9 (d, JPCˆ13.2 Hz, arom., CH), 121.1 (d,
JPCˆ126.6 Hz, arom., CP), 121.7 (d, JPCˆ10.4 Hz, arom.,
CH), 151.6 (d, JPCˆ7.7 Hz, arom.), 154.3 (d, JPCˆ20.9 Hz,
arom.), and 157.5 (d, JPCˆ2.6 Hz, arom.); 31PNMR
1
31: Colorless crystals, mp 68–71ЊC; H NMR (200 MHz,
CDCl3) d 1.29 (9H, s, t-Bu), 1.56 (12H, s, CMe2), 2.02 (4H,
3
3
t, JHHˆ7.6 Hz, CH2CH2O), 2.92 (4H, t, JHHˆ7.6 Hz,
3
CH2O), 3.16 (6H, s, OMe), 3.55 (6H, d, JPHˆ11.0 Hz,
POMe), and 7.39 (2H, d, JPHˆ5.1 Hz, arom.); 13C{1H}
4
NMR (50 MHz, CDCl3) d 30.2 (s, CMe2), 30.9 (s, CMe3),
34.6 (d, JPCˆ1.5 Hz, CMe3), 41.7 (d, 3JPCˆ3.8 Hz, CMe2),
5
2
1
47.3 (s, CH2CH2O), 52.2 (d, JPCˆ7.2 Hz, POMe), 58.4 (s,
(81 MHz, CDCl3) d 34.6 (d, JPHˆ632.9 Hz); IR (KBr)
1
CH2OMe), 69.7 (s, CH2O), 120.5 (d, JPCˆ99.9 Hz, arom.,
2393, 1603, 1460, 1383, 1363, 1240, 1223, 1066, 980,
881, 773, and 557 cmϪ1; MS (70 eV) m/z (rel intensity)
310 (Mϩ; 3), 295 (MϩϪMe; 65), 280 (MϩϪ2Me; 100),
and 263 (MϩϪMe–OMeϪ1; 80). Found: m/z 310.1718.
Calcd for C17H27O3P: M, 310.1698.
3
CP), 123.5 (d, JPCˆ15.6 Hz, arom., CH), 152.7 (d,
4JPCˆ4.2 Hz, arom.), and 157.0 (d, JPCˆ8.8 Hz, arom.);
2
31P{1H} NMR (81 MHz, CDCl3) d 23.3; IR (KBr) 1591,
1460, 1394, 1362, 1232, 1207, 1173, 1122, 1061, 1047,
1020, 829, 762, and 638 cmϪ1; MS (70 eV) m/z (rel inten-
sity) 442 (Mϩ; 0.1), 427 (MϩϪMe; 1), 411 (MϩϪOMe; 2),
397 (MϩϪCH2OMe; 2), 384 (MϩϪCH2CH2OMeϩ1; 21),
and 275 (MϩϪt-Bu–P(O)(OMe)2Ϫ1; 100).
29b: Colorless oil, 1H NMR (200 MHz, CDCl3) d 1.32 (9H,
s, t-Bu), 1.34 (3H, s, CMe2), 1.40 (3H, s, CMe2), 1.60 (3H, s,
CMe2), 1.61 (3H, s, CMe2), 3.34 (3H, s, OMe), 3.60 (1H, d,
3
2JHHˆ10.2 Hz, CH2OMe), 3.97 (1H, dd, JPHˆ15.1 Hz and
2
2JHHˆ11.3 Hz, CH2OP), 4.01 (1H, d, JHHˆ10.2 Hz,
Preparation of the ethyl phosphinates 33a,b. To a
solution of bromobenzene 10a in THF (25 mL) was
added 1.62 mmol of butyllithium at room temperature,
and the resulting solution was stirred for 10 min. Then
the solution was cooled to 0ЊC, and 6.18 mmol of
diethyl phosphorochloridite was added to the solution.
The resulting mixture was stirred at room temperature
for 1 h. The solvent was removed under reduced pressure,
the residue was worked up using hexane and water, the
organic phase was dried over MgSO4, and the solvent was
evaporated. Chromatographic treatment of the residue
afforded 331.4 mg (63%) of ethyl [4-t-butyl-2,6-bis(1-meth-
oxy-1-methylethyl)phenyl]phosphinate (33a). Compound
33b was obtained from 10b by a similar procedure in 45%
yield.
CH2OMe), 4.30 (1H, dd, 3JPHˆ13.9 Hz and
4
2JHHˆ11.3 Hz, CH2OP), 7.34 (1H, dd, JPHˆ3.6 Hz and
4
4JHHˆ1.8 Hz, arom.), 7.49 (1H, dd, JPHˆ5.0 Hz and
1
4JHHˆ1.8 Hz, arom.), and 7.68 (1H, d, JPHˆ586.5 Hz,
PH); 13C{1H} NMR (50 MHz, CDCl3) d 26.9 (s, CMe2),
28.0 (s, CMe2), 28.2 (s, CMe2), 28.6 (s, CMe2), 30.9 (s,
3
CMe3), 35.1 (s, CMe3), 37.7 (d, JPCˆ4.6 Hz, CMe2), 43.1
3
(d, JPCˆ1.9 Hz, CMe2), 59.0 (s, OMe), 71.1 (d,
2JPCˆ5.7 Hz, CH2OP), 82.1 (s, CH2OMe), 121.7 (d,
3
1JPCˆ111.4 Hz, arom., CP), 121.8 (d, JPCˆ10.0 Hz,
3
arom., CH), 124.8 (d, JPCˆ12.6 Hz, arom., CH), 151.2 (s,
2
arom.), 151.3 (d, JPCˆ4.9 Hz, arom.), and 154.9 (d,
2JPCˆ2.7 Hz, arom.); 31PNMR (81 MHz, CDCl3) d 22.3
1
(d, JPHˆ585.0 Hz); IR (neat) 1726, 1601, 1473, 1396,

M. Yoshifuji et al. / Tetrahedron 56 (2000) 43–55
53
4
33a: Colorless oil; 1H NMR (200 MHz, CDCl3) d 1.30 (9H,
s, t-Bu), 1.37 (3H, t, 3JHHˆ7.0 Hz, CH2Me), 1.65 (12H, br. s,
CMe2), 3.28 (6H, s, OMe), 3.9–4.3 (2H, m, CH2Me), 7.24
PH), and 7.16 (2H, d, JPHˆ2.2 Hz, arom.); 13C{1H}
NMR (50 MHz, CDCl3) d 28.3 (s, CMe2), 31.2 (s, CMe3),
34.4 (s, CMe3), 50.3 (d, JPCˆ5.4 Hz, OMe), 80.0 (d,
4
3
(2H, d, JPHˆ4.4 Hz, arom.), and 7.92 (1H, d,
3JPCˆ1.9 Hz, CMe2), 122.8 (d, JPCˆ1.0 Hz, arom., CH),
1JPHˆ585.1 Hz, PH); 13C{1H} NMR (50 MHz, CDCl3) d
126.2 (d, 1JPCˆ27.5 Hz, arom., CP), 148.1 (d,
3
4
16.2 (d, JPCˆ7.7 Hz, CH2Me), 27.9 (s, CMe2), 28.6 (s,
2JPCˆ4.2 Hz, arom.), and 149.0 (d, JPCˆ1.1 Hz, arom.);
1
CMe2), 30.9 (s, CMe3), 34.6 (s, CMe3), 49.6 (s, OMe),
31P NMR (81 MHz, CDCl3) d Ϫ129.1 (t, JPHˆ216.6 Hz);
2
3
62.6 (d, JPCˆ4.8 Hz, CH2), 79.1 (d, JPCˆ3.1 Hz, CMe2),
IR (KBr) 2355, 2339, 1598, 1462, 1415, 1377, 1360, 1240,
1182, 1169, 1068, 877, 847, 816, 735, and 606 cmϪ1; MS
(70 eV) m/z (rel intensity) 310 (Mϩ; 4), 278 (MϩϪPH2ϩ1;
100), and 263 (MϩϪPH2–Meϩ1; 85). Found: m/z
310.2051. Calcd for C18H31O2P: M, 310.2062.
122.7 (d, 3JPCˆ12.6 Hz, arom., CH), 124.3 (d,
1JPCˆ138.8 Hz, arom., CP), 152.6 (d, JPCˆ8.8 Hz,
2
arom.), and 153.6 (d, JPCˆ3.0 Hz, arom.); 31PNMR
4
1
(81 MHz, CDCl3) d 23.3 (d, JPHˆ585.3 Hz); IR (neat)
2447, 1603, 1464, 1381, 1362, 1190, 1211, 1171, 1068,
1020, 935, 879, 781, 752, and 623 cmϪ1; MS (70 eV) m/z
(rel intensity) 370 (Mϩ; 2), 369 (MϩϪ1; 10), 338
(MϩϪOMeϪ1; 100), 309 (MϩϪ2OMeϩ1; 96), and 295
(MϩϪOMe–OEtϩ1; 84). Found: m/z 370.2254. Calcd for
C20H35O4P: M, 370.2273.
1,2-Bis[4-t-butyl-2,6-bis(3-methoxy-1,1-dimethylpropyl)-
phenyl]diphosphene (35c). Phosphonous dichloride 26c
was prepared from 201.2 mg (0.487 mmol) of the bromo-
benzene 10c by a method described above, then the solvent
and unreacted PCl3 was removed under reduced pressure.
THF (20 mL) was added to the residue and the solution was
cooled to Ϫ78ЊC. To the solution was added 1.0 mmol of
lithium naphthalenide at the same temperature and the
resulting mixture was stirred for 30 min. Then the reaction
mixture was warmed to room temperature, and the solvent
was removed in vacuo. Hexane was added to the residue, the
insoluble material was removed by filtration, and the solvent
was evaporated. Chromatographic treatment (Al2O3/hex-
ane–benzene) of the residue afforded 6.9 mg (4%) of the
diphosphene 35c.
33b: Colorless oil; 1H NMR (200 MHz, CDCl3) d 1.31 (9H,
3
s, t-Bu), 1.33 (3H, t, JHHˆ7.0 Hz, CH2Me), 1.56 (6H, s,
CMe2), 1.58 (6H, s, CMe2), 3.34 (6H, s, OMe), 3.60 (2H, d,
2
2JHHˆ9.3 Hz, CH2OMe), 3.64 (2H, d, JHHˆ9.3 Hz,
CH2OMe), 3.9–4.2 (2H, m, CH2Me), 7.50 (2H, d,
1
4JPHˆ4.5 Hz, arom.), and 8.11 (1H, d, JPHˆ569.1 Hz,
PH); 13C{1H} NMR (50 MHz, CDCl3) d 15.7 (d,
4
3JPCˆ7.1 Hz, CH2Me), 29.0 (d, JPCˆ11.2 Hz, CMe2),
5
30.9 (s, CMe3), 34.9 (d, JPCˆ1.1 Hz, CMe3), 42.8 (d,
2
3JPCˆ4.2 Hz, CMe2), 58.9 (s, OMe), 62.3 (d, JPCˆ6.1 Hz,
CH2Me), 82.9 (s, CH2OMe), 124.8 (d, 3JPCˆ13.5 Hz, arom.,
35c: Yellow crystals, mp 116–117ЊC (decomp); H NMR
(200 MHz, CDCl3) d 1.35 (18H, s, t-Bu), 1.47 (24H, s,
1
1
CH), 126.0 (d, JPCˆ127.0 Hz, arom., CP), 152.6 (d,
4
2
2JPCˆ9.2 Hz, arom.), and 152.7 (d, JPCˆ3.3 Hz, arom.);
CMe2), 2.10 (8H, t, JHHˆ7.3 Hz, CH2CH2O), 3.06 (8H, t,
31P NMR (81 MHz, CDCl3) d 27.9 (d, JPHˆ568.6 Hz);
2JHHˆ7.3 Hz, CH2O), 3.17 (12H, s, OMe), and 7.33 (4H, br.
s, arom.); 13C{1H} NMR (50 MHz, CDCl3) d 31.2 (CMe3),
32.6 (CMe2), 34.6 (CMe3), 40.4 (CMe2), 44.9 (CH2CH2O),
58.4 (OMe), 70.0 (CH2O), 122.6 (arom., CH), 138.4 (arom.,
CP), 149.4 (arom.), and 152.1 (arom.); 31P{1H} NMR
(81 MHz, CDCl3) d 493.8; UV (hexane) 291 (log e 4.0),
343 (3.6), and 466 nm (2.8); IR (neat) 1589, 1460, 1360,
1196, 1113, 962, 879, and 746 cmϪ1; FAB-MS m/z (rel
intensity) 365 (Mϩ/2ϩ1; 100), 349 (Mϩ/2ϪMe; 21), 333
(Mϩ/2ϪOMe; 21), 306 (Mϩ/2Ϫt-BuϪ1; 52), and 274 (Mϩ/
2Ϫ2CH2OMe; 25) (molecular ion peak was not observed in
the mass spectrum).
1
IR (neat) 2466, 1599, 1461, 1396, 1363, 1222, 1108,
1025, 944, 750, and 619 cmϪ1; MS (70 eV) m/z (rel inten-
sity) 398 (Mϩ; 3), 383 (MϩϪMe; 6), 353 (MϩϪOEt; 34),
261 (MϩϪP(O)H(OEt)–CH2OMeϩ1; 100), and 57 (t-Buϩ;
41). Found: m/z 398.2586. Calcd for C22H39O4P: M,
398.2586.
Preparation of the phosphines 34a–c. A THF (5 mL) solu-
tion of the phosphinate 33a (52.0 mg, 0.140 mmol) was
added to 0.261 mmol of LiAlH4 at 0ЊC and the resulting
mixture was stirred for 1 h. An appropriate amount of
methanol was added to the mixture and the solvent was
removed in vacuo. Hexane was added to the residue and
insoluble materials were filtered off. Removal of the solvent
under reduced pressure followed by chromatographic treat-
ment (SiO2/CHCl3) afforded 11.7 mg (27%) of [4-t-butyl-
2,6-bis(1-methoxy-1-methylethyl)phenyl]phosphine (34a).
[4-t-Butyl-2,6-bis(2-methoxy-1,1-dimethylethyl)phenyl]-
General procedure for the reaction of phosphines 34a–c
with sulfur. Phosphine 34 was formed in situ by the method
described above. To a mixture of phosphine 34a–c
(0.17 mmol) and elemental sulfur (0.6 mg-atom) were
added successively benzene (10 mL) and DBU
(0.02 mmol), then the resulting mixture was stirred at
room temperature for 1–3 days. The solvent was removed
under reduced pressure and the residue was washed with
hexane. Chromatographic treatment (SiO2/CHCl3) of the
washings afforded 38a–c.
1
phosphine (34b) [dP (CDCl3)ˆϪ129.4 (t, JPHˆ209.3 Hz)]
was formed from 33b by a similar procedure, however,
attempted isolation of 34b resulted in decomposition.
Similarly, attempted isolation of [4-t-butyl-2,6-bis(3-
methoxy-1,1-dimethylpropyl)phenyl]phosphine (34c) [dP
1
(CDCl3)ˆϪ130.2 (t, JPHˆ209.2 Hz)], formed by the reac-
38a (53% yield): mp 115–117ЊC; 1H NMR (200 MHz,
CDCl3) d 1.34 (9H, s, t-Bu), 1.60 (3H, s, CMe2OP), 1.67
(6H, br. s, CMe2OMe), 1.74 (3H, s, CMe2OP), 2.39 (3H, d,
3JPHˆ15.8 Hz, SMe), 3.39 (3H, s, OMe), 7.09 (1H, pseudo t,
tion of phosphonous dichloride 26c with LiAlH4, resulted in
decomposition of 34c.
34a: Colorless crystals; mp 124–125ЊC (decomp); 1H NMR
(200 MHz, CDCl3) d 1.30 (9H, s, t-Bu), 1.68 (12H, s,
4JPHˆ4JHHˆ1.7 Hz, arom.), and 7.36 (1H, dd, JPHˆ6.5 Hz
4
and JHHˆ1.7 Hz, arom.); 13C{1H}NMR (50 MHz, CDCl3)
4
1
2
CMe2), 3.17 (6H, s, OMe), 4.16 (2H, d, JPHˆ216.4 Hz,
d 14.5 (d, JPCˆ4.2 Hz, SMe), 25.9 (s, CMe2), 26.9 (d,

54
M. Yoshifuji et al. / Tetrahedron 56 (2000) 43–55
JPCˆ1.0 Hz, CMe2), 29.5 (d, JPCˆ1.6 Hz, CMe2), 30.8 (d,
24), 396 (MϩϪS; 82), 381 (MϩϪSMe; 83), 371 (MϩϪt-
Bu; 55), 355 (MϩϪt-Bu–MeϪ1; 93), 323 (MϩϪt-Bu–
SMeϪ1; 93), and 57 (t-Buϩ; 100). Found: m/z 428.1971.
Calcd for C22H37O2PS2: M, 428.1973.
5
JPCˆ2.7 Hz, CMe2), 31.1 (s, CMe3), 35.2 (d, JPCˆ1.1 Hz,
3
CMe3), 48.1 (s, OMe), 78.0 (d, JPCˆ0.8 Hz, CMe2OMe),
2
3
87.7 (d, JPCˆ4.2 Hz, CMe2OP), 117.1 (d, JPCˆ14.2 Hz,
3
arom., CH), 123.0 (d, JPCˆ11.4 Hz, arom., CH), 124.9 (d,
1JPCˆ107.2 Hz, arom., CP), 151.0 (d, JPCˆ8.4 Hz, arom.),
Typical procedure for the reaction of phosphines 34a–c
with selenium. Phosphine 34a–c was formed in situ by the
method described above. To a mixture of phosphine 34a–c
(0.18 mmol) and elemental selenium (0.58 mg-atom) were
2
2
152.4 (d, JPCˆ23.2 Hz, arom.), and 156.7 (d, 4JPCˆ3.1 Hz,
arom.); 31P{1H} NMR (81 MHz, CDCl3) d 106.4; IR (KBr)
1603, 1456, 1377, 1363, 1252, 1224, 1190, 1144, 1072,
1061, 947, 916, 901, 877, 847, 802, 775, 698, 611, and
559 cmϪ1; MS (70 eV) m/z (rel intensity) 372 (Mϩ; 46),
342 (MϩϪOMeϩ1; 12), 340 (MϩϪS; 12), 325
(MϩϪSMe; 20), and 295 (MϩϪSMe–Sϩ2; 100). Found:
m/z 372.1345. Calcd for C18H29O2PS2: M, 372.1347.
added successively benzene (10 mL) and
a
base
(0.03 mmol), then the resulting mixture was stirred at
room temperature for 1–3 days. The solvent was removed
under reduced pressure and the residue was washed with
hexane. The hexane-insoluble material was removed by
filtration, and the filtrate was treated with column chromato-
graphy to give 41 and/or 42.
38b (11% yield): Colorless oil; 1H NMR (600 MHz, CDCl3)
d 1.32 (9H, s, t-Bu), 1.35 (3H, s, CMe2), 1.42 (3H, s, CMe2),
3
1.75 (6H, s, CMe2), 2.35 (3H, d, JPHˆ15.2 Hz, SMe), 3.32
41a (3% yield): Colorless crystals, mp 150–151ЊC; 1H
NMR (200 MHz, CDCl3) d 1.34 (9H, s, t-Bu), 1.59 (3H,
s, CMe2), 1.66 (3H, s, CMe2), 1.68 (3H, s, CMe2), 1.74 (3H,
2
(3H, s, OMe), 3.67 (1H, d, JHHˆ9.6 Hz, CH2OMe), 3.97
3
2
(1H, dd, JPHˆ22.5 Hz and JHHˆ11.2 Hz, CH2OP), 4.09
3
(1H,
d,
2JHHˆ9.6 Hz,
CH2OMe),
4.48
(1H,
s, CMe2), 2.37 (3H, d, JPHˆ13.6 Hz, SeMe), 3.43 (3H, s,
3
2
4
dd, JPHˆ13.9 Hz and JHHˆ11.2 Hz, CH2OP), 7.34
OMe), 7.07 (1H, pseudo-t, JPHˆ4JHH4 ˆ1.9 Hz, arom.), and
4
4
4
(1H, dd, JPHˆ4.4 Hz and JHHˆ2.0 Hz, arom.), and 7.59
7.31 (1H, dd, JPHˆ6.5 Hz and JHHˆ1.6 Hz, arom.);
4
4
2
(1H, dd, JPHˆ6.2 Hz and JHHˆ2.0 Hz, arom.); 13C{1H}
13C{1H} NMR (50 MHz, CDCl3) d 8.2 (d, JPCˆ4.2 Hz,
2
NMR (150 MHz, CDCl3) d 13.8 (d, JPCˆ3.6 Hz, SMe),
SeMe), 25.9 (s, CMe2), 26.8 (d, JPCˆ1.1 Hz, CMe2), 29.6
27.0 (s, CMe2), 29.4 (s, CMe2), 30.2 (s, CMe2), 30.8 (s,
CMe2), 30.9 (s, CMe3), 35.1 (s, CMe3), 38.1 (d,
(s, CMe2), 30.8 (d, JPCˆ2.5 Hz, CMe2), 31.2 (s, CMe3), 35.1
5
(d, JPCˆ1.1 Hz, CMe3), 47.5 (s, OMe), 78.1 (s,
3
2
3JPCˆ4.6 Hz, CMe2), 44.1 (d, JPCˆ2.3 Hz, CMe2), 59.0
CMe2OMe), 89.5 (d, JPCˆ7.2 Hz, CMe2OP), 117.1 (d,
2
3
(s, OMe), 72.6 (d, JPCˆ8.5 Hz, CH2OP), 82.6 (s,
3JPCˆ13.7 Hz, arom., CH), 122.9 (d, JPCˆ10.9 Hz, arom.,
3
1
CH2OMe), 123.1 (d, JPCˆ11.0 Hz, arom., CH), 126.1 (d,
CH), 126.6 (d, JPCˆ83.5 Hz, arom., CP), 150.5 (d,
1JPCˆ91.6 Hz, arom., CP), 126.9 (d, JPCˆ13.9 Hz, arom.,
2JPCˆ7.9 Hz, arom.), 150.7 (d, JPCˆ22.0 Hz, arom.), and
3
2
2
4
CH), 151.1 (d, JPCˆ12.5 Hz, arom.), 151.2 (d,
156.6 (d, JPCˆ3.1 Hz, arom.); 31P{1H} NMR (81 MHz,
2JPCˆ6.7 Hz, arom.), and 154.3 (d, JPCˆ3.2 Hz, arom.);
CDCl3) d 70.6, satellite, JSePˆ841.9 and 436.6 Hz; IR
4
1
31P{1H}NMR (81 MHz, CDCl3) d 97.4; IR (neat) 1600,
1469, 1107, 1041, 812, 701, and 684 cmϪ1; MS (70 eV)
m/z (rel intensity) 400 (Mϩ; 0.4), 385 (MϩϪMe; 10), 367
(MϩϪS; 7), 353 (MϩϪSMe; 100), 321 (MϩϪSMe–S; 11),
and 57 (t-Buϩ; 17). Found: m/z 400.1666. Calcd for
C20H33O2PS2: M, 400.1660.
(KBr) 1600, 1458, 1377, 1362, 1190, 1070, 947, 914, 899,
877, 845, 771, 642, 570, 536, and 521 cmϪ1; MS (70 eV) m/
z (rel intensity) 468 (Mϩ; 17), 373 (MϩϪSeMe; 24), and
293 (MϩϪSeMe–Se; 100). Found: m/z 468.0216. Calcd for
C18H29O2PSe2: M, 468.0236.
41b (trace): 31P{1H} NMR (81 MHz, CDCl3) d 82.9,
38c (26% yield): Colorless oil; 1H NMR (600 MHz, CDCl3)
d 1.17 (3H, s, CMe2), 1.30 (9H, s, t-Bu), 1.59 (1H, m,
CH2CH2O), 1.62 (3H, s, CMe2), 1.62 (3H, s, CMe2), 1.84
satellite, JPSeˆ832.4 and 420.4 Hz.
1
42c (11% yield): Colorless oil; 1H NMR (200 MHz, CDCl3)
d 1.26 (3H, s, CMe2), 1.30 (9H, s, t-Bu), 1.56 (3H, s, CMe2),
1.70 (3H, s, CMe2), 1.78 (3H, s, CMe2), 1.91 (3H, d,
3JPHˆ11.8 Hz, SeMe), 2.0–2.2 (2H, m, CH2CH2O), 2.7–
2.9 (3H, m, CH2CH2O and CH2O), 3.1–3.2 (1H, m,
CH2O), 3.17 (3H, s, OMe), 4.1–4.3 (1H, m, CH2O), 4.5–
3
(3H, s, CMe2), 1.91 (3H, d, JPHˆ15.3 Hz, SMe), 2.18 (1H,
m, CH2CH2O), 2.39 (1H, m, CH2CH2O), 2.91 (1H, m,
CH2O), 3.03 (1H, m, CH2O), 3.11 (1H, m, CH2CH2O),
3.17 (3H, s, MeO), 4.19 (1H, m, CH2OP), 4.70 (1H, m,
4
4
CH2OP), 7.31 (1H, dd, JPHˆ4.5 Hz and JHHˆ2.1 Hz,
4
4
4
arom.), and 7.36 (1H, dd, JPHˆ5.9 Hz and JHHˆ2.1 Hz,
arom.); 13C{1H} NMR (150 MHz, CDCl3) d 13.5 (d,
2JPCˆ4.5 Hz, SMe), 27.6 (s, CMe2), 30.9 (s, CMe3), 32.4
4.6 (1H, m, CH2O), 7.30 (1H, dd, JPHˆ4.6 Hz
4
4
and JHHˆ2.0 Hz, arom.), and 7.43 (1H, dd, JPHˆ5.6 Hz
and 4JHHˆ2.0 Hz, arom.); 13C{1H} NMR (50 MHz, CDCl3)
4
5
2
(d, JPCˆ6.2 Hz, CMe2), 34.7 (d, JPCˆ1.4 Hz, CMe3),
d 5.0 (d, JPCˆ4.9 Hz, SeMe), 28.3 (s, CMe2), 30.8 (s,
3
5
37.2 (s, CMe2), 39.9 (d, JPCˆ2.6 Hz, CH2CH2OP), 42.1
CMe3), 31.7 (s, CMe2), 34.7 (d, JPCˆ1.5 Hz, CMe3), 35.8
3
3
3
(d, JPCˆ3.2 Hz, CMe2), 42.6 (d, JPCˆ2.6 Hz, CMe2),
45.9 (s, CH2CH2OMe), 58.4 (s, OMe), 63.9 (d,
2JPCˆ6.5 Hz, CH2OP), 70.0 (s, CH2OMe), 123.1 (d,
(s, CMe2), 40.1 (s, CH2CH2OP), 41.7 (d, JPCˆ3.8 Hz,
CMe2), 41.8 (d, 3JPCˆ3.4 Hz, CMe2), 46.7 (s,
2
CH2CH2OMe), 58.3 (s, OMe), 64.3 (d, JPCˆ7.1 Hz,
3JPCˆ13.3 Hz, arom., CH), 125.2 (d, JPCˆ14.9 Hz, arom.,
CH2OP), 69.9 (s, CH2OMe), 122.7 (d, JPCˆ13.7 Hz,
3
3
1
3
CH), 131.9 (d, JPCˆ99.3 Hz, arom., CP), 152.3 (d,
arom., CH), 125.4 (d, JPCˆ15.2 Hz, arom., CH), 129.1
4JPCˆ4.5 Hz, arom.), 154.1 (d, JPCˆ11.8 Hz, arom.), and
(d, JPCˆ119.4 Hz, arom., CP), 152.7 (d, JPCˆ4.2 Hz,
2
1
4
157.6 (d, JPCˆ6.6 Hz, arom.); 31P{1H} NMR (81 MHz,
arom.), 154.1 (d, JPCˆ13.4 Hz, arom.), and 155.8 (d,
2
2
CDCl3) d 101.9; IR (neat) 1591, 1464, 1389, 1363, 1169,
1117, 1066, 1038, 985, 781, 677, and 600 cmϪ1; MS
(70 eV) m/z (rel intensity) 428 (Mϩ; 2), 413 (MϩϪMe;
2JPCˆ8.4 Hz, arom.); 31P{1H} NMR (81 MHz, CDCl3) d
1
(42.2, satellite, JSePˆ424.2 Hz; IR (neat) 1593, 1463,
1223, 1117, 1068, 985, 757, and 609 cmϪ1; MS (70 eV)

M. Yoshifuji et al. / Tetrahedron 56 (2000) 43–55
55
m/z (rel intensity) 445 (MϩϪMe; 1) and 365 (MϩϪSeMe;
100) (molecular ion peak was not observed in the mass
spectrum).
1993, 34, 1043. (b) Yoshifuji, M.; Sangu, S.; Hirano, M.; Toyota,
K. Chem. Lett. 1993, 1715.
6. (a) Yoshifuji, M.; An, D.-L.; Toyota, K.; Yasunami, M. Chem.
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Yasunami, M. Tetrahedron Lett. 1994, 35, 4379. (c) Yoshifuji,
M.; Higeta, N.; An, D.-L.; Toyota, K. Chem. Lett. 1998, 17.
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1993, 66, 3440.
9. Yoshifuji, M.; Otoguro, A.; Toyota, K. Bull. Chem. Soc. Jpn.
1994, 67, 1503.
Acknowledgements
This work was supported in part by the Grants-in-Aid for
Scientific Research Nos. 02403008 and 03214101 from
the Ministry of Education, Science, Sports and Culture,
Japanese Government.
10. Yoshifuji, M.; Kamijo, K.; Toyota, K. Chem. Lett. 1994,
1931.
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