Alkyl- and arylation of oxacyclic ethers with triethylsilyl triflate-2,4,6-collidine-Gilman reagent combination: Remarkable discrimination of two ether oxygens

Article abstract of DOI:10.3987/COM-06-S(K)46

The alkylation reaction of oxacyclic ethers such as THP-ethers, THF-ethers, etc., has been developed. The treatment of oxacyclic ether with TESOTf and 2,4,6-collidine gives the collidinium salt intermediate obtained by the reaction of the cyclic oxygen at

Full text of DOI:10.3987/COM-06-S(K)46

HETEROCYCLES, Vol. 72, 2007
529
HETEROCYCLES, Vol. 72, 2007, pp. 529 - 540. © The Japan Institute of Heterocyclic Chemistry
Received, 15th December, 2006, Accepted, 22nd January, 2007, Published online, 23rd January, 2007. COM-06-S(K)46
ALKYL- AND ARYLATION OF OXACYCLIC ETHERS WITH
TRIETHYLSILYL TRIFLATE―2,4,6-COLLIDINE―GILMAN
REAGENT COMBINATION: REMARKABLE DISCRIMINATION OF
TWO ETHER OXYGENS†
Hiromichi Fujioka,* Takuya Ohnaka, Takashi Okitsu, Ozora Kubo,
Kazuhisa Okamoto, Yoshinari Sawama, and Yasuyuki Kita*
Graduate School of Pharmaceutical Sciences, Osaka University, 1-6,
Yamada-oka, Suita, Osaka, 565-0871, Japan
fujioka@phs.osaka-u.ac.jp; kita@phs.osaka-u.ac.jp
Abstract – The alkylation reaction of oxacyclic ethers such as THP-ethers,
THF-ethers, etc., has been developed. The treatment of oxacyclic ether with
TESOTf and 2,4,6-collidine gives the collidinium salt intermediate obtained by
the reaction of the cyclic oxygen atom. The addition of Gilman reagent to the
mixture gives the alkylated product. The reaction proceeds with high
chemoselectivity though there are two different oxygen atoms in the oxacyclic
ethers.
C-C bond formation is a fundamental reaction in organic synthesis. Recently, we succeeded in developing
new C-C bond formation reactions of acetals with Gilman reagents via the collidinium intermediates i
obtained from acetals (Scheme 1, eq. 1).1 We then proposed to apply this reaction to oxacyclic ethers,
because they also have acetal structures. However, two oxygen atoms in the oxacyclic ethers are different
from each other, whereas the two oxygen atoms in the acetal function of eq. 1 are equivalent. When the
reaction proceeds via the intermediate ii obtained by the reaction of the cyclic oxygen atom, a single
product 4 would be obtained (Scheme 1, eq. 2a). On the other hand, when the reaction proceeds via
†This paper is dedicated to Professor Yoshito Kishi on the occasion of his 70th birthday.

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HETEROCYCLES, Vol. 72, 2007
the intermediate iii obtained by the reaction of the exo-cyclic oxygen atom, two products 5 and 6 would
be obtained (Scheme 1, eq. 2b). We quite recently found that the deprotection of THP-ethers 3 (n = 1)
with TESOTf―2,4,6-collidine followed by H2O treatment proceeded via the intermediate ii (n = 1).2 We
now found that the reaction of oxacyclic ethers (n = 0, 1, 2) with TESOTf―2,4,6-collidine followed by
the reaction with Gilman reagents proceeds in a highly chemoselective manner and gives the products via
the intermediate ii (Scheme 1).
OR
TESOTf
2,4,6-collidine
CH2Cl2, 0 oC
OTf
OR
R2
OR
OR
R2 CuLi
R1
N
2
(eq. 1)
R
R1
R1
Gilman
reagent
1
2
i
R
O
OTES
OTES
R1
n
n
R2 CuLi
2
R1
N
R2
O
(eq. 2a)
OTf
TESOTf
2,4,6-collidine
CH2Cl2, 0 oC
R
4
ii
R1
n
O
O
R
R
3
OTf
(n=0,1,2)
R2 CuLi
n
2
O
N
+
n
R2
R1
(eq. 2b)
O
+
5
iii
OTES
R1
OTES
6
Scheme 1 Highly chemoselective alkylation of the acetals and oxacyclic ethers
Since THP-ethers are the most popular oxacyclic ethers in organic synthesis,3 we first examined the
reaction of THP-ethers. Thus, the treatment of the decanol-THP ether 3a with TESOTf (2.0
equiv.)―2,4,6-collidine (3.0 equiv.) gave the polar compound (TLC check).4 The addition of Gilman
reagent, lithium diphenylcuprate (3.0 equiv.),5 to the mixture afforded the product 4a in high yield (86%)
(Scheme 2). Product 4a was a compound obtained by the reaction of the cyclic oxygen atom. That is, the
reaction proceeds via the intermediate ii (Scheme 1, eq. 2a). No formation of the product via the
intermediate iii (Scheme 1, eq. 2b) was observed. These results showed that the reaction proceeded in a
highly chemoselective manner.
TESOTf (2 eq.)
2,4,6-collidine (3 eq.)
Ph2CuLi (3 eq.)
0 oC, 0.5 h
CH2Cl2, 0 oC, 0.5 h
C10H21O
OTES
4a (86%)
Ph
C10H21O
O
3a
Scheme 2. The reaction of decanol-THP ether 3a

HETEROCYCLES, Vol. 72, 2007
531
The generality of the reaction, i.e., high chemoselectivity, was observed for the reaction of 3a and various
Gilman reagents (Table 1). For comparison, the result in Scheme 2 is shown in entry 1. Every reaction
afforded the products 4b-d via the intermediates ii (Scheme 1, eq. 2a) obtained by the reaction of the
cyclic oxygen atom.
Table 1. Alkylation of THP-ether 3a with various Gilman reagents
TESOTf (2 eq.)
2,4,6-collidine (3 eq.)
R2 CuLi (3 eq.)
3
OTES
2
CH2Cl2, 0 oC, 0.5 h
0 oC, 0.5 h
R2
C10H21O
O
C10H21O
3a
4a-d
R2
Entry
Product Yield (%)
Ph
4a
4b
4c
4d
86
95
94
82
1
2
3
4
Me
n-Bu
TMSCH2
The reactions of various THP-ethers 3a-e, in which the alcohol units are different from each other, with
lithium diphenylcuprate were next examined (Table 2). For THP-ethers 3a-d from the primary alcohols,
every reaction well proceeded to give the desired product in high yield (entries 1-4). The reaction
conditions are very mild, and benzyl alcohol and allyl alcohol were used without problems (entries 2 and
4). In the case of THP-ether 3e from the secondary alcohol, the yield of the desired product decreased
(entry 5).
Table 2. Alkylation of tetrahydropyranyl ethers 3a-e with Ph2CuLi
TESOTf (2 eq.)
2,4,6-collidine (3 eq.) Ph2CuLi (3 eq.)
Product
Substrate
Entry
CH2Cl2, 0 oC, 0.5 h
Substrate
0 oC, 0.5 h
Product
3OTES
Ph
Yield (%)
RO
O
RO
3a: R = C10H21
3b: R = PhCH2
3c: R = Ph(CH2)3
3d: R = Allyl
4a: R = C10H21
4e: R = PhCH2
4f : R = Ph(CH2)3
4g: R = Allyl
1
2
3
4
86
86
81
79
3 OTES
Ph
5
62
O
O
O
8
8
3e
4h

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HETEROCYCLES, Vol. 72, 2007
Table 3 shows the applicability of other cyclic ethers in this reaction. The reactions of decanol ethers 3f-i
using lithium diphenylcuprate as a carbon nucleophile were examined. The 6-membered oxacyclic ether
3f having a methyl substituent next to the acetal carbon gave the desired product 4i in 79% yield (entry 1).
Tetrahydrofuranyl ether 3g afforded the desired product 4j in high yield (96%) (entry 2). However, the
introduction of a methyl group next to the acetal carbon decreased the yield of the product 4k (entry 3).
Furthermore, compound 3i with a 7-membered oxacyclic ring well proceeded to give the desired
compound 4l in high yield (94%) (entry 4).
Table 3. Alkylation of Various Oxacyclic Ethers 3f-i with Ph2CuLi
TESOTf (2 eq.)
2,4,6-collidine (3 eq.) Ph2CuLi (3 eq.)
Product
Yield (%)
79
Substrate
Entry
CH2Cl2, 0 oC, 0.5 h
0 oC, 0.5 h
Substrate
Product
b)
a)
3
OTES
1
2
3
9
9 O
Ph
O
O
O
O
3f
4i
2
OTES
96
61
9
9
9
O
Ph
3g
4j
c)
d)
2 OTES
Ph
9
O
O
O
3h
4k
4 OTES
Ph
4
94
9
9
O
O
O
3i
4l
a) 1 to 1 mixture of two diastereomers were used. b) 1 to 1 mixture of two
diastereomers were obtained. c) 6 to 1 mixture of two diastereomers were used. d) 2 to
1 mixture of two diastereomers were obtained.
The characteristic feature of this reaction is the high chemoselectivity. This aspect is also obvious from
the following reactions (Scheme 3). Thus, compound 3j having dioxolane ketal and THP-ether units in
the molecule afforded the monophenyl product 4m obtained by the reaction at only the THP-part. This
tendency was observed even in compound 3k having an acetal, not a ketal. Thus, compound 3k having
dioxolane acetal and THP-ether units in the molecule gave the monophenyl product 4n, obtained by the
reaction at only the THP-position, and the diphenyl product 7 obtained by the reaction at the dioxolane

HETEROCYCLES, Vol. 72, 2007
533
part and THP part. No formation of a monophenyl product, obtained by the reaction at only the dioxolane
part, was observed. This phenomenon became clearer when a lower amount of reagent was used. Thus,
the treatment of 3k with TESOTf (1.2 equiv.) and 2,4,6-collidine (1.8 equiv.) followed by the addition of
lithium diphenylcuprate (1.8 equiv.) gave 4n in 41% yield and 7 in 9% yield along with the recovered
starting material 3k (18 %). These results show that the THP-unit reacts much faster than the dioxolane
unit, although the dioxolane unit also reacts under the same conditions.1
TESOTf (2 eq.)
2,4,6-collidine (3 eq.)
CH2Cl2, 0 oC, 0.5 h
3
OTES
O
O
O
O
Ph2CuLi (3 eq.)
0 oC, 0.5 h
O
O
O
Ph
10
10
3j
4m
80%
1) TESOTf
2,4,6-collidine
3
O
OTES
3
O
Ph
OTES
CH2Cl2, 0 oC, 0.5 h
+
O
O
10
O
2
Ph
O
TESO
O
O
10
O
Ph
2) Ph2CuLi
0 oC, 0.5 h
10
7
3k
4n
TESOTf (2 eq.)
2,4,6-collidine (3 eq.)
Ph2CuLi (3 eq.)
27%
52%
9%
TESOTf (1.2 eq.)
2,4,6-collidine (1.8 eq.)
Ph2CuLi (1.8 eq.)
41%
Scheme 3. The reactions of the compounds having THP-unit and acetal unit in the molecule
The reaction mechanism is rationalized as follows. First, the formation of the collidinium salts ii (Scheme
1, eq. 2a) occurs under the TESOTf―2,4,6-collidine conditions. The reason why the cyclic oxygen atoms
predominantly react is not clear at this stage, though the oxacyclic ethers have two different oxygen atoms.
The formation of the collidinium salt ii is quite easy as shown in Scheme 3, although the dioxolane acetal
is also affected under the reaction conditions as previously reported by us.6 The nucleophilic substitution
of the 2,4,6-collidine substituent by carbon nucleophiles then gives the desired products.
In conclusion, the alkylation reaction of oxacyclic ethers has been developed. This is an extension of the
alkylation of acetals.1 However, it contains several new findings. The reaction proceeds with a high
chemoselectivity though there are two different oxygen atoms in the oxacyclic ethers. The reaction
proceeds in various oxacyclic ethers. Furthermore, it is noteworthy that the reaction selectively proceeds
in the compounds having a dioxolane acetal unit and an oxacyclic ether unit in the molecule.

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HETEROCYCLES, Vol. 72, 2007
EXPERIMENTAL
General techniques
1
The H and 13C NMR spectra were measured by 300 MHz or 270 MHz spectrometers with
o
tetramethylsilane as an internal standard at 20-25 C. IR spectra were recorded by a diffuse reflectance
measurement of samples dispersed in KBr powder. Merck silica gel 60 was used for column
chromatography.
General Procedure for Preparation of Oxacyclic Ethers 3a-e, 3g, and 3j,k.
According to a literature,7 a solution of alcohol (1 equiv.), pyridinium p-toluenesulfonate (PPTS) (0.1
equiv.) and 3,4-dihydro-2H-pyran or 2,3-dihydrofuran (1.8-2 equiv.) in dry CH2Cl2 (0.1 M) was stirred at
rt. After checking disappearance of the alcohol on TLC, the mixture was quenched with saturated aqueous
NaHCO3 and extracted with CH2Cl2. The organic layer was washed with brine, dried over Na2SO4,
filtered, and evaporated in vacuo. The residue was purified by flash SiO2 column chromatography to give
a THP-ether. 3a,8a 3b,8b 3c,8c 3d,8d and 3g8e are known in the literatures.
1
3e: colorless oil, IR (KBr) 2925, 913, 743 cm-1; H NMR (300 MHz, CDCl3) δ 0.88 (3H, t, J = 6.6 Hz),
1.10 (3/2H, d, J = 6.3 Hz), 1.22 (3/2H, d, J = 6.3 Hz), 1.27-1.58 (20H, m), 1.63-1.95 (2H, m), 3.46-3.53
13
(1H, m), 3.67-3.97 (2H, m), 4.64 (1/2H, t, J = 3.5 Hz), 4.71 (1/2H, t, J = 3.5 Hz); C NMR (75 MHz,
CDCl3) δ 14.0, 19.0, 19.7, 20.0, 21.5, 22.6, 25.4, 25.46, 25.51, 25.8, 29.3, 29.5, 29.56, 29.58, 29.67, 29.70,
31.1, 31.8, 36.4, 37.5, 62.3, 62.8, 71.0, 73.8, 95.4, 98.5; HRMS (FAB) calcd for C16H33O2 (M++H)
257.2481, found 257.2489.
1
3j: colorless oil, IR (KBr) 2925, 1078 cm-1; H NMR (300 MHz, CDCl3) δ 0.90 (3H, t, J = 7.4 Hz),
1.27-1.43 (16H, m), 1.43-1.87 (12H, m), 3.38 (1H, dt, J = 9.5, 6.7 Hz), 3.46-3.53 (1H, m), 3.73 (1H, dt, J
= 9.5, 6.7 Hz), 3.84-3.90 (1H, m), 3.93 (4H, br s), 4.58 (1H, t, J = 3.5 Hz); 13C NMR (75 MHz, CDCl3) δ
8.1, 19.7, 23.8, 25.5, 26.2, 29.5, 29.55, 29.58, 29.7, 29.8, 29.9, 30.8, 36.7, 62.3, 64.9, 67.7, 98.8, 112.1;
HRMS (FAB) calcd for C21H40O4Na (M++Na) 379.2824, found 379.2826.
1
3k: colorless oil, IR (KBr) 2926, 912, 743 cm-1; H NMR (300 MHz, CDCl3) δ 1.21-1.47 (15H, m),
1.49-1.75 (10H, m), 1.74-1.88 (1H, m), 3.38 (1H, dt, J = 9.6, 6.8 Hz), 3.46-3.54 (1H, m), 3.73 (1H, dt, J =
13
9.6, 6.8 Hz), 3.82-4.02 (5H, m), 4.58 (1H, t, J = 3.6 Hz), 4.84 (1H, t, J = 4.9 Hz); C NMR (75 MHz,
CDCl3) δ 19.7, 24.1, 25.5, 26.2, 29.46, 29.47, 29.52, 29.54, 29.7, 30.8, 33.9, 62.3, 64.8, 67.7, 98.8, 104.7;
HRMS (FAB) calcd for C19H36O4Na (M++Na) 351.2511, found 351.2510.
General Procedure for Preparation of Oxacyclic Ethers 3f and 3h.
n-BuLi (1.1 equiv.) in hexane was added dropwise to a solution of diisopropylamine (1.1 equiv.) in dry

HETEROCYCLES, Vol. 72, 2007
535
o
o
THF (2.0 M) at 0 C. After being stirred for 1 h at the same temperature and cooled to -78 C,
δ-valerolactone or γ-butyrolactone was added dropwise to the reaction mixture. After being stirred for 0.5
h at the same temperature, hexamethylphosphoric triamide (HMPA) (1.0 equiv.) was added dropwise to
the reaction mixture. After being stirred for 0.5 h at the same temperature, MeI (1.0 equiv.) was added
dropwise to the reaction mixture and the mixture was warmed to -40 oC. After checking disappearance of
the δ-valerolactone on TLC, the mixture was quenched with saturated aqueous NH4Cl and extracted with
EtOAc. The organic layer was washed with brine, dried over Na2SO4, filtered, and evaporated in vacuo.
DIBAL-H (1.05 equiv.) in hexane was added dropwise to a solution of the crude residue in dry CH2Cl2
(0.2 M) at -78 oC. After checking disappearance of the residue on TLC, the mixture was quenched with
MeOH and H2O, filtered with celite, and evaporated in vacuo. A solution of the crude product,
pyridinium p-toluenesulfonate (PPTS) (0.1 equiv.) and decanol (2.0 equiv.) in dry CH2Cl2 (0.2 M) was
stirred at rt. After checking disappearance of the crude product on TLC, the mixture was quenched with
saturated aqueous NaHCO3 and extracted with CH2Cl2. The organic layer was washed with brine, dried
over Na2SO4, filtered, and evaporated in vacuo. The residue was purified by flash SiO2 column
chromatography to give a THP-ether.
1
3f: colorless oil, IR (KBr) 2928, 913, 742 cm-1; H NMR (300 MHz, CDCl3) δ 0.86-0.97 (6H, m),
1.14-1.26 (15H, m), 1.43-1.68 (5H, m), 1.71-1.87 (1H, m), 3.28-3.54 (2H, m), 3.64-3.85 (3/2H, m),
13
3.92-4.06 (1H, m), 4.51 (1/2H, d, J = 2.7 Hz); C NMR (75 MHz, CDCl3) δ 14.1, 16.72, 16.74, 22.7,
24.6, 25.5, 26.10, 26.13, 26.2, 29.3, 29.4, 29.57, 29.59, 29.6, 29.7, 29.8, 31.9, 34.9, 35.1, 59.4, 65.0, 67.3,
68.7, 100.3, 106.0; HRMS (FAB) calcd for C16H33O2 (M++H) 257.2481, found 257.2480.
1
3h: colorless oil, IR (KBr) 2925, 913, 743 cm-1; H NMR (300 MHz, CDCl3) δ 0.88 (3H, t, J = 6.5 Hz),
1.04 (3H, d, J = 6.9 Hz), 1.10-1.39 (15H, m), 1.40-1.57 (2H, m), 2.06-2.26 (2H, m), 3.29-3.39 (1H, m),
3.57-3.70 (1H, m), 3.77-4.00 (2H, m), 4.69 (6/7H, br s), 4.82 (1/7H, d, J = 4.5 Hz); 13C NMR (75 MHz,
CDCl3) δ 14.1, 17.7, 22.7, 26.1, 29.3, 29.4, 29.5, 29.6, 29.7, 31.8, 31.9, 39.5, 66.6, 67.5, 109.7; HRMS
(FAB) calcd for C15H30O2Na (M++Na) 265.2143, found 265.2151.
Preparation of Oxacyclic Ether 3i.
DIBAL-H (9.95 mL, 9.64 mmol) in hexane was added dropwise to a solution of 6-hexanolactone (1.00 g,
8.76 mmol) in dry CH2Cl2 (43.8 mL) at -78 oC. After checking disappearance of 6-hexanolactone on TLC,
the mixture was quenched with MeOH and H2O, and filtered with celite, and evaporated in vacuo. A
solution of the crude product, pyridinium p-toluenesulfonate (PPTS) (75.4 mg, 0.438 mmol) and decanol
(3.34 mL, 17.5 mmol) in dry CH2Cl2 (29.2 mL) was stirred at rt. After checking disappearance of the
crude product on TLC, the mixture was quenched with saturated aqueous NaHCO3 and extracted with
CH2Cl2. The organic layer was washed with brine, dried over Na2SO4, filtered, and evaporated in vacuo.

536
HETEROCYCLES, Vol. 72, 2007
The residue was purified by flash SiO2 column chromatography to give a THP-ether 3i (997 mg, 44%).
This reaction is not optimized.
3i: colorless oil, IR (KBr) 2924, 1128, 964 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.88 (3H, t, J = 6.6 Hz),
1.26-1.68 (22H, m), 1.81-1.86 (1H, m), 2.01-2.10 (1H, m), 3.36 (1H, dt, J = 9.6, 6.8 Hz), 3.49-3.55 (1H,
m), 3.68 (1H, dt, J = 9.6, 6.8 Hz), 3.76-3.84 (1H, m), 4.69 (1H, t, J = 6.9 Hz); 13C NMR (75 MHz,
CDCl3) δ 14.1, 22.65, 22.69, 26.2, 29.3, 29.4, 29.50, 29.54, 29.6, 29.7, 30.7, 31.9, 35.0, 61.5, 67.2, 101.8;
HRMS (FAB) calcd for C16H33O2 (M++H) 257.2481, found 257.2480.
Typical Reaction Procedure: Reaction of THP-ether 3a and Ph2CuLi
2,4,6-Collidine (69 µL, 0.522 mmol) and TESOTf (79 µL, 0.348 mmol) were added to a solution of a
o
THP-ether 3a (42.2 mg, 0.174 mmol) in CH2Cl2 (1.74 mL) at 0 C under N2. The reaction mixture was
stirred at the same temperature. After checking disappearance of 3a on TLC (0.5 h), Ph2CuLi (0.522
mmol, 0.4 M diethyl ether solution prepared according to Johnson’s method9) was added to the reaction
mixture and stirred for 0.5 h. Disappearance of the polar component was ascertained by TLC analysis.
The reaction mixture was quenched with saturated aqueous NH4Cl and stirred for more than 10 min at rt.
The mixture was extracted with CH2Cl2. The organic layer was washed with brine, dried over Na2SO4,
filtered, and evaporated in vacuo. The residue was purified by flash SiO2 column chromatography using
hexanes-Et2O (50/1) to give 4a (64.9 mg, 86%) as a colorless oil.
4a: colorless oil, IR (KBr) 2928, 1101, 748 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.58 (6H, q, J = 7.9 Hz),
0.88 (3H, t, J = 6.9 Hz), 0.94 (9H, t, J = 7.9 Hz), 1.15-1.32 (16H, m), 1.38-1.67 (5H, m), 1.75-1.87 (1H,
m), 3.21 (1H, dt, J = 9.0, 6.7 Hz), 3.30 (1H, dt, J = 9.0, 6.7 Hz), 3.57 (2H, t, J = 6.5 Hz), 4.16 (1H, t, J =
13
6.6 Hz), 7.22-7.35 (5H, m); C NMR (75 MHz, CDCl3) δ 4.4, 6.8, 14.1, 22.3, 22.7, 26.2, 29.3, 29.5,
29.56, 29.59, 29.9, 31.9, 32.8, 38.3, 62.8, 68.9, 82.2, 126.5, 127.2, 128.2, 143.3; Anal. Calcd for
C27H50O2Si: C, 74.59; H, 11.59. Found: C, 74.79; H, 11.50.
4b: colorless oil, IR (KBr) 2932, 1097, 743 cm-1; 1H NMR (270 MHz, CDCl3) δ 0.60 (6H, q, J = 7.9 Hz),
0.88 (3H, t, J = 6.5 Hz), 0.96 (9H, t, J = 7.9 Hz), 1.12 (3H, d, J = 6.3 Hz), 1.26-1.49 (16H, m), 1.50-1.62
13
(6H, m), 3.27-3.37 (2H, m), 3.40-3.51 (1H, m), 3.60 (2H, t, J = 6.5 Hz); C NMR (75 MHz, CDCl3) δ
4.4, 6.8, 14.1, 19.7, 21.9, 22.7, 26.2, 29.3, 29.5, 29.58, 29.61, 30.2, 31.9, 32.9, 36.5, 62.9, 68.6, 75.2;
HRMS (FAB) calcd for C22H49O2Si (M++H) 373.3502, found 373.3477.
4c: colorless oil, IR (KBr) 2928, 1097, 743 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.60 (6H, q, J = 7.8 Hz),
0.86-0.99 (15H, m), 1.27-1.66 (28H, m), 3.15-3.20 (1H, m), 3.39 (2H, t, J = 6.6 Hz), 3.60 (2H, t, J = 6.6
13
Hz); C NMR (75 MHz, CDCl3) δ 4.4, 6.8, 14.1, 21.8, 22.7, 22.9, 26.3, 27.6, 29.3, 29.5, 29.58, 29.60,
29.63, 30.2, 31.9, 33.1, 33.8, 33.9, 62.9, 69.0, 79.4; HRMS (FAB) calcd for C25H55O2Si (M++H)

HETEROCYCLES, Vol. 72, 2007
537
415.3971, found 415.3984.
4d: colorless oil, IR (KBr) 2855, 912, 743 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.10 (9H, s), 0.59 (6H, q,
J = 7.9 Hz), 0.76 (1H, dd, J = 14.7, 6.9 Hz), 0.87 (3H, t, J = 6.8 Hz), 0.92 (1H, dd, J = 14.7, 7.2 Hz), 0.95
(9H, t, J = 7.9 Hz), 1.26-1.58 (22H, m), 3.31-3.37 (3H, m), 3.60 (2H, t, J = 6.8 Hz); 13C NMR (75 MHz,
CDCl3) δ –0.7, 4.4, 6.8, 14.1, 21.6, 22.7, 22.8, 26.3, 29.3, 29.5, 29.58, 29.61, 30.2, 31.9, 33.0, 36.3, 62.9,
68.3, 77.3; Anal. Calcd for C25H56O2Si2: C, 67.49; H, 12.69. Found: C, 67.53; H, 12.46.
1
4e: colorless oil, IR (KBr) 912, 743 cm-1; H NMR (270 MHz, CDCl3) δ 0.57 (6H, q, J = 7.9 Hz), 0.93
(9H, t, J = 7.9 Hz), 1.23-1.35 (1H, m), 1.43-1.72 (4H, m), 1.81-1.95 (1H, m), 3.56 (2H, t, J = 6.4 Hz),
13
4.24 (1H, d, J = 11.9 Hz), 4.29 (1H, t, J = 6.6 Hz), 4.44 (1H, d, J = 11.9 Hz), 7.26-7.39 (10H, m); C
NMR (75 MHz, CDCl3) δ 4.4, 6.8, 22.2, 32.7, 38.2, 62.7, 70.4, 81.5, 126.8, 127.4, 127.5, 127.7, 128.3,
128.4, 138.6, 142.6; HRMS (FAB) calcd for C24H37O2Si (M++H) 385.2563, found 385.2553.
4f: colorless oil, IR (KBr) 2951, 1101, 748 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.57 (6H, q, J = 7.9 Hz),
0.94 (9H, t, J = 7.9 Hz), 1.12-1.69 (5H, m), 1.77-1.91 (3H, m), 2.58-2.75 (2H, m), 3.24 (1H, dt, J = 9.3,
6.4 Hz), 3.34 (1H, dt, J = 9.3, 6.4 Hz), 3.58 (2H, t, J = 6.6 Hz), 4.17 (1H, dd, J = 7.8, 5.7 Hz), 7.13-7.35
13
(10H, m); C NMR (75 MHz, CDCl3) δ 4.4, 6.8, 22.3, 31.5, 32.5, 32.8, 38.2, 62.8, 68.0, 82.3, 125.7,
126.6, 127.3 128.2, 128.3, 128.4, 142.1, 143.1; Anal. Calcd for C26H40O2Si: C, 75.67; H, 9.77. Found: C,
75.34; H, 9.73.
4g: colorless oil, IR (KBr) 2953, 1265, 748 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.57 (6H, q, J = 7.9 Hz),
0.94 (9H, t, J = 7.9 Hz), 1.15-1.70 (5H, m), 1.79-1.91 (1H, m), 3.57 (2H, t, J = 6.6 Hz), 3.74 (1H, dd like,
J = 12.7, 6.2 Hz), 3.90 (1H, dd like, J = 12.7, 5.1 Hz), 4.26 (1H, t, J = 6.6 Hz), 5.12-5.25 (2H, m), 5.88
13
(1H, m), 7.24-7.36 (5H, m); C NMR (75 MHz, CDCl3) δ 4.4, 6.7, 22.2, 32.8, 38.1, 62.8, 69.5, 81.5,
116.6, 126.7, 127.4, 128.3, 135.0, 142.6; Anal. Calcd for C20H34O2Si: C, 71.80; H, 10.24. Found: C,
71.96; H, 10.21.
4h: colorless oil, IR (KBr) 2928, 1099, 743 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.57 (6H, q, J = 7.9 Hz),
0.85-0.99 (14H, m), 1.10 (1H, d, J = 6.2 Hz), 1.15-1.35 (15H, m), 1.38-1.62 (6H, m), 1.72-1.84 (1H, m),
3.27-3.59 (1H, m), 3.57 (2H, t, J = 6.9 Hz), 4.28 (1H, dd, J = 7.7, 5.6 Hz), 7.21-7.35 (5H, m); 13C NMR
(75 MHz, CDCl3) δ 4.4, 6.8, 14.1, 20.9, 22.3, 22.7, 25.2, 29.3, 29.6, 29.7, 29.9, 31.9, 32.8, 35.8, 38.6,
62.8, 73.4, 80.1, 126.6, 127.1, 128.1, 144.2; HRMS (FAB) calcd for C28H52O2SiLi (M++Li) 455.3897,
found 455.3890.
1
4i: colorless oil, IR (KBr) 2855, 913, 743 cm-1; H NMR (300 MHz, CDCl3) δ 0.51-0.64 (6H, m), 0.69
(3/2H, d, J = 6.6 Hz), 0.80-0.99 (12H+3/2H, m), 1.11-1.35 (15H, m), 1.43-1.75 (6H, m), 3.12-3.33 (2H,
13
m), 3.48-3.61 (2H, m), 3.89 (1/2H, d, J = 7.5 Hz), 3.98 (1/2H, d, J = 6.3 Hz), 7.22-7.34 (5H, m); C
NMR (75 MHz, CDCl3) δ 4.36, 4.40, 6.77, 6.79, 14.1, 15.2, 15.7, 22.7, 26.2, 28.8, 29.2, 29.3, 29.5, 29.59,

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29.62, 29.9, 30.3, 30.5, 31.9, 39.4, 39.9, 63.2, 63.4, 69.1, 69.2, 86.1, 86.7, 127.0, 127.1, 127.2, 127.5,
127.89, 127.91, 141.7, 142.0; HRMS (FAB) calcd for C28H52O2SiLi (M++Li) 455.3897, found 455.3925.
4j: colorless oil, IR (KBr) 2926, 1275, 748 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.57 (6H, q, J = 7.9 Hz),
0.88 (3H, t, J = 6.6 Hz), 0.94 (9H, t, J = 7.9 Hz), 1.17-1.30 (15H, m), 1.43-1.85 (5H, m), 3.21 (1H, dt, J =
9.2, 6.7 Hz), 3.30 (1H, dt, J = 9.2, 6.7 Hz), 3.53-3.66 (2H, m), 4.18 (1H, dd, J = 7.8, 5.1 Hz), 7.25-7.35
13
(5H, m); C NMR (75 MHz, CDCl3) δ 4.4, 6.8, 14.1, 22.7, 26.2, 29.27, 29.31, 29.5, 29.56, 29.60, 29.9,
31.9, 34.7, 62.8, 68.9, 82.1, 126.6, 127.2, 128.2, 143.2; Anal. Calcd for C26H48O2Si: C, 74.22; H, 11.50.
Found: C, 74.30; H, 11.32.
4k: colorless oil, IR (KBr) 2856, 1263, 748 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.50-0.62 (6H, m), 0.73
(1H, d, J = 6.9 Hz), 0.86-0.98 (14H, m), 1.20-1.39 (15H, m), 1.50-1.65 (8/3H, m), 1.84-1.99 (4/3H, m),
3.13-3.36 (2H, m), 3.50-3.72 (2H, m), 3.92 (1/3H, d, J = 6.6 Hz), 4.01 (2/3H, d, J = 6.0 Hz), 7.23-7.34
13
(5H, m); C NMR (75 MHz, CDCl3) δ 4.39, 4.43, 6.78, 6.80, 14.1, 15.1, 16.3, 22.7, 26.3, 29.3, 29.5,
29.58, 29.62, 29.9, 31.9, 36.0, 36.3, 36.68, 36.71, 61.1, 61.5, 69.1, 69.2, 86.0, 86.8, 127.0, 127.1, 127.3,
127.5, 127.90, 127.94, 141.7, 141.9; HRMS (FAB) calcd for C27H51O2Si (M++H) 435.3658, found
435.3656.
4l: colorless oil, IR (KBr) 2927, 1100, 746 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.58 (6H, q, J = 7.9 Hz),
0.88 (3H, t, J = 6.6 Hz), 0.95 (9H, t, J = 7.9 Hz), 1.13-1.66 (23H, m), 1.74-1.86 (1H, m), 3.21 (1H, dt, J =
9.0, 6.7 Hz), 3.29 (1H, dt, J = 9.0, 6.7 Hz), 3.57 (2H, t, J = 6.6 Hz), 4.16 (1H, t, J = 6.6 Hz), 7.22-7.35
(5H, m); 13C NMR (75 MHz, CDCl3) δ 4.4, 6.8, 14.1, 22.7, 25.7, 26.2, 29.3, 29.5, 29.56, 29.60, 29.9, 31.9,
32.8, 38.5, 62.9, 68.9, 82.2, 126.6, 127.2, 128.2, 143.3; HRMS (EI) calcd for C28H52O2Si (M+) 448.3736,
found 448.3725.
4m: colorless oil, IR (KBr) 2854, 1101, 743 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.57 (6H, q, J = 7.9 Hz),
0.90 (3H, t, J = 7.4 Hz), 0.94 (9H, t, J = 7.9 Hz), 1.25-1.40 (17H, m), 1.42-1.70 (10H, m), 1.75-1.87 (1H,
m), 3.21 (1H, dt, J = 9.0, 6.7 Hz), 3.30 (1H, dt, J = 9.0, 6.7 Hz), 3.57 (2H, t, J = 6.6 Hz), 3.93 (4H, br s),
4.16 (1H, t, J = 6.6 Hz), 7.22-7.35 (5H, m); 13C NMR (75 MHz, CDCl3) δ 4.4, 6.7, 8.1, 22.2, 23.8, 26.2,
29.4, 29.55, 29.57, 29.59, 29.8, 29.89, 29.93, 32.7, 36.7, 38.2, 62.8, 64.9, 68.9, 82.2, 112.1, 126.5, 127.2,
128.2, 143.3; HRMS (FAB) calcd for C33H60O4SiNa (M++Na) 571.4159, found 571.4193.
4n: colorless oil, IR (KBr) 2930, 912, 743 cm-1; 1H NMR (300 MHz, CDCl3) δ 0.58 (6H, q, J = 8.0 Hz),
0.94 (9H, t, J = 8.0 Hz), 1.24-1.68 (25H, m), 1.75-1.86 (1H, m), 3.21 (1H, dt, J = 9.0, 6.7 Hz), 3.30 (1H,
dt, J = 9.0, 6.7 Hz), 3.57 (2H, t, J = 6.6 Hz), 3.80-4.02 (4H, m), 4.16 (1H, dd, J = 7.5, 5.7 Hz), 4.84 (1H, t,
J = 4.8 Hz), 7.20-7.35 (5H, m); 13C NMR (75 MHz, CDCl3) δ 4.4, 6.8, 22.2, 24.1, 26.2, 29.4, 29.49,
29.52, 29.54, 29.6, 29.9, 32.8, 33.9, 38.3, 62.8, 64.8, 68.9, 82.2, 104.7, 126.6, 127.2, 128.2, 143.3; HRMS
(FAB) calcd for C31H56O4SiNa (M++Na) 543.3846, found 543.3851.

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1
7: colorless oil, IR (KBr) 2856, 912, 744 cm-1; H NMR (300 MHz, CDCl3) δ 0.53-0.67 (12H, m), 0.94
(9H, t, J = 7.8 Hz), 0.95 (9H, t, J = 7.8 Hz), 1.22-1.65 (24H, m), 1.76-1.87 (2H, m), 3.17-3.43 (4H, m),
3.57 (2H, t, J = 6.6 Hz), 3.67-3.79 (2H, m), 4.16 (1H, t, J = 6.6 Hz), 4.24 (1H, t, J = 6.6 Hz), 7.23-7.35
13
(10H, m); C NMR (75 MHz, CDCl3) δ 4.4, 6.8, 22.2, 25.8, 26.2, 29.5, 29.6, 29.9, 32.8, 38.26, 38.33,
62.3, 62.8, 68.9, 70.0, 77.2, 82.2, 82.7, 126.6, 126.7, 127.21, 127.24, 128.2, 143.0, 143.3; HRMS (FAB)
calcd for C43H76O4Si2Li (M++Li) 719.5442, found 719.5440.
ACKNOWLEDGEMENTS
This work was supported by a Grant-in-Aid for Scientific Research (S) and a Grant-in-Aid for Scientific
Research for Exploratory Research from the Japan Society for the Promotion of Science and by a
Grant-in-Aid for Scientific Research on Priority Areas (17035047) from the Ministry of Education,
Culture, Sports, Science, and Technology, Japan.
REFERENCES AND NOTES
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collidinium salt intermediates iv to give alcohols in good yields [H. Fujioka, T. Okitsu, T. Ohnaka, Y.
Sawama, O. Kubo, K. Okamoto, and Y. Kita, Adv. Synth. Catal, in press.]
TESOTf
O
4
2,4,6-collidine
CH2Cl2, 0 oC
R
OTES
N
R
OTHP
R
OH
then H2O work-up
OTf
iv
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