Synthesis of oxaspiro[m.n] skeletons based on the Nicholas reaction

Article abstract of DOI:10.1016/S0040-4020(02)00173-4

Treatment of alkyne-Co₂(CO)₆ complexes possessing a methylidene moiety as well as a terminal hydroxy functionality with SnCl₄ at 0°C effected tandem ring-closure reactions resulting in the formation of 1-oxaspiro[4.4]nonane, 1-oxaspiro[4.5]decane, 6-oxaspiro[4.5]decane, and 1-oxaspiro[5.5]undecane frameworks in high yields.

Full text of DOI:10.1016/S0040-4020(02)00173-4

TETRAHEDRON
Pergamon
Tetrahedron 58(2002) 2755±2762
Synthesis of oxaspiro[m.n] skeletons
based on the Nicholas reaction
Chisato Mukai,p Haruhisa Yamashita, Misato Sassa and Miyoji Hanaoka
Faculty of Pharmaceutical Sciences, Kanazawa University, Takara-machi, Kanazawa 920-0934, Japan
Received 25 January 2002; accepted 18February 2002
AbstractÐTreatment of alkyne±Co2(CO)6 complexes possessing a methylidene moiety as well as a terminal hydroxy functionality with
SnCl4 at 08C effected tandem ring-closure reactions resulting in the formation of 1-oxaspiro[4.4]nonane, 1-oxaspiro[4.5]decane, 6-oxaspiro-
[4.5]decane, and 1-oxaspiro[5.5]undecane frameworks in high yields. q 2002 Elsevier Science Ltd. All rights reserved.
Alkyne±Co2(CO)6 complexes, which are easily prepared by
reacting alkynes with commercially available dicobaltocta-
carbonyl (Co2(CO)8), have been shown to liberate the corre-
sponding propynyl cation species upon treatment with a
suitable acid, such as a Lewis acid. The newly generated
cation species are subsequently inter- or intramolecularly
captured by various kinds of nucleophiles. This reaction is
well known as the Nicholas reaction.1 During the course of
our studies on the development of an ef®cient method for
constructing oxacycles based on the Nicholas reaction, we
noted a highly stereoselective procedure for preparing ®ve-
to seven-membered oxacycles 22 by taking advantage of
endo-mode cyclization of the alkyne±cobalt complexes 1
with an epoxy functionality adjacent to the complexed
alkyne moiety (Scheme 1). In addition, a procedure for
the formation of medium-sized oxacycles 4 (eight or nine
members)3 was developed by combining the propynyl
cation-stabilizing ability of alkyne±Co2(CO)6 complexes 3
with the b-effect of the trimethylsilyl group, as shown in
Scheme 1. In this paper, we describe the use of alkyne±
Co2(CO)6 complexes 5 to construct oxaspiro[4.4]nonane,
oxaspiro[4.5]decane, and oxaspiro[5.5]undecane frame-
works 6 via tandem ring-closure steps initiated by a
Nicholas-type reaction.
yield. An alkyne moiety was introduced by successive
oxidation of 8 under Swern conditions and the addition of
phenylacetylide to give the alkyne derivative 9 in 49%
yield. Methylation of the propynyl alcohol moiety of 9
with methyl iodide was followed by desilylation to provide
10, which was subsequently treated with Co2(CO)8 to
give the alkyne±Co2(CO)6 complex 11 in 83% overall
yield from 9.
At the inception of this program, we investigated ring
construction of 1-oxaspiro[4.4]nonane derivative 13. The
required starting alkyne±Co2(CO)6 complex 11 for ring-
closure experiments was synthesized as depicted in Scheme
2. Wittig reaction of the known 4-heptanone derivative 73
with methylidenetriphenylphosphorane was followed by
debenzylation with 2,3-dichloro-5,6-dicyano-1,4-benzo-
quinone (DDQ) to give the alcohol derivative 8 in 87%
Keywords: oxaspiro[m.n] skeletons; Nicholas reaction; dicobaltocta-
carbonyl.
p
Corresponding author. Tel.: 181-76-234-4411; fax: 181-76-234-4410;
e-mail: cmukai@kenroku.kanazawa-u.ac.jp
Scheme 1.
0040±4020/02/$ - see front matter q 2002 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020(02)00173-4

2756
C. Mukai et al. / Tetrahedron 58 *2002) 2755±2762
Scheme 2. Reagents and conditions: (a) Ph3PCH3Br, tBuOK, THF; (b) DDQ, CH2Cl2, H2O; (c) DMSO, (COCl)2, Et3N, CH2Cl2; (d) phenylacetylene, nBuLi;
(e) MeI, NaH, THF; (f) TBAF, THF; (g) Co2(CO)8, Et2O; (h) Ac2O, DMAP, CH2Cl2.
Alkyne±Co2(CO)6 complex 11 was then subjected to Lewis
acid-catalyzed ring-formation reaction to obtain the 1-oxa-
spiro[4.4]nonane framework. Treatment of the methoxy
derivative 11 with 1.1 equiv. of TMSOTf in CH2Cl2 at
2408C gave a complex mixture. Similar treatment with
TiCl4 again gave an intractable mixture. However, when
complex 11 was exposed to BF3´OEt2 at 08C, the desired
1-oxaspiro derivatives 13a and 13b were obtained in 30%
yield in a ratio of 67:33. After screening various Lewis
acids,4 SnCl4 was found to be suitable for this ring-closure
reaction. Thus, a mixture of 13a and 13b (13a/13bˆ87:13)
was produced in 53% yield on exposure to 2 equiv. of SnCl4
at 08C for 1 h. Although 1-oxaspiro[4.4]nonane derivative
13 was obtained, the yield was far from satisfactory. A
simple mechanistic explanation involves an initial genera-
tion of the propynyl cation species A,1 which induces
cationic ole®n-cyclization with the methylene moiety
anchimerically assisted by the terminal hydroxy group to
give rise to the formation of the 1-oxaspiro skeleton. Conse-
quently, we expected that changing the methoxy group at
the propynyl position to a more powerful leaving group such
as an acetoxy group would improve the chemical yield in
this ring-closure reaction. Thus, alkyne±Co2(CO)6 complex
12 with an acetoxy group was prepared in 82% overall yield
from 9 by successive acetylation, desilylation and cobalt
complex formation (see Section 1). Alkyne±Co2(CO)6
complex 12 was then exposed to the best conditions identi-
®ed thus far i.e. 2 equiv. of SnCl4 in CH2Cl2 at 08C for 1 h,
and this resulted in the formation of 13a and 13b in 83%
yield in a ratio of 83:17. Cobalt complexation is necessary
for this tandem ring-closure reaction. In fact, no reaction
took place when the acetyl derivative of uncomplexed
alkyne 9 was exposed to the conditions used for the syn-
thesis of 13.
Regeneration of the triple bond from the alkyne±Co2(CO)6
moiety is already well established. Thus, 13a was converted
into alkyne derivative 14 (90% yield) by treatment with
cerium(IV) ammonium nitrate (CAN)5 in acetone at room
temperature (Scheme 3). The stereochemistry of 13 was
con®rmed by an NOE experiment with the quinoxaline
derivative 16. Oxidation of 13 with ruthenium dioxide6
in the presence of sodium periodate effected not only
1,2-dicarbonylation of the triple bond, but also conversion
of the tetrahydrofuran ring into the g-lactone to produce
a
labile 4-butanolide derivative with 1,2-dicarbonyl
Scheme 3. Reagents and conditions: (a) CAN, acetone; (b) RuO2, CCl4, CH3CN, H2O; (c) o-phenylenediamine, CH2Cl2; (d) LiAlH4, Et2O; (e) TBDPSCl,
Imid., DMF; (f) TMS-Imid., CH2Cl2.

C. Mukai et al. / Tetrahedron 58 *2002) 2755±2762
2757
t
Scheme 4. Reagents and conditions: (a) nBuLi, THF; (b) H2, 5%Pd±C, AcOEt; (c) Ph3PCH3Br, BuOK, THF; (d) Py´SO3, Et3N, DMSO, CH2Cl2;
(e) phenylacetylene, nBuli; (f) Ac2O, DMAP, CH2Cl2; (g) PPTS, MeoH; (h) Co2(CO)8, Et2O; (i) Cl, Imid., DMF; (j) DDQ, CH2Cl2, H2O; (k) TBAF, THF.
functionality. This compound was subsequently treated with
o-phenylenediamine to give the quinoxaline derivative 157
in 53% yield. Reduction of 15 with LiAlH4 afforded the diol,
the primary hydroxy group of which was ®rst silylated with
TBDPSCl. The resulting tertiary hydroxy moiety was then
protected with a TMS group, resulting in the formation of 16
in an overall yield of 79%. Since an NOE experiment with
16 revealed 8.2% enhancement between the TMS group and
Ha, stereochemistries of both 13 and 16 were con®rmed as
depicted in Schemes 2 and 3.
oxaspiro[4.5]decane skeletons. The starting cobalt complex
20 for the oxaspiro[5.5]undecane derivative was prepared as
follows (Scheme 4). d-Valerolactone was treated with the
n
acetylide, adjusted from the reaction of 17 with BuLi, to
give the crude ring-opened product, which was then hydro-
genated under a hydrogen atmosphere in the presence of 5%
Pd±C to give the saturated 1-hydroxynonanone derivative.
This compound was exposed to the Wittig conditions
described for the conversion of 7 to 9, and this resulted in
the formation of 18 in 58% overall yield. Consecutive
oxidation, addition of phenylacetylide, and acetylation of
18 provided 19 in 96% yield. A tetrahydropyranyl moiety
of 19 was then removed by pyridinium p-toluenesulfonate
(PPTS) in MeOH, and the resulting hydroxy compound was
treated with Co2(CO)8 in Et2O. Thus, the required alkyne±
Co2(CO)6 complex 20 was obtained in 93% yield from 19.
The next step in this program was to see whether this pro-
cedure could be used to prepare other oxaspiro frameworks.
We chose d-valerolactone as a common starting material for
the synthesis of alkyne±Co2(CO)6 complexes 20, 27, and
31, which would produce the oxaspiro[5.5]undecane and
Scheme 5.

2758
C. Mukai et al. / Tetrahedron 58 *2002) 2755±2762
The two other alkyne±Co2(CO)6 complexes 27 and 31 for
the ring-closure reaction were obtained in a manner similar
to that described for the preparation of 20 (Scheme 4).
NaHCO3. The resulting precipitates were ®ltered off and the
®ltrate was extracted with Et2O, which was washed with
water and brine, dried, and concentrated to dryness. The
residue was chromatographed with hexane±AcOEt (4:1)
to give 8 (2.31 g, 87%) as a colorless oil: IR 3456,
Treatment of the alkyne±Co2(CO)6 complex 20 with
2 equiv. of SnCl4 in CH2Cl2 at 08C nonstereoselectively
afforded the ring-closed products, 1-oxaspiro[5.5]undecane
derivatives 32a and 32b (56:44),8 in 63% yield. The ring-
closure of 20 proceeded as anticipated, but no signi®cant
stereoselectivity was observed. This is in sharp contrast to
the case of 11, where 13a was predominantly formed (13a/
13bˆ83:17). Similarly, the 6-oxaspiro[4.5]decane deriva-
tives 33a and 33b (49:51)8 were formed nonstereo-
selectively in 81% yield when 27 was exposed to SnCl4.
In addition, alkyne±Co2(CO)6 complex 31 underwent
acid-catalyzed ring-closure, which gave rise to the forma-
tion of a mixture of 1-oxaspiro[4.5]decane compounds 34a
and 34b in a ratio of 51:49 (Scheme 5).8
1645 cm21
;
1H NMR d 4.75 (2H, s), 3.65 (2H, t, Jˆ
6.4 Hz), 3.61 (2H, t, Jˆ6.4 Hz), 2.10 (2H, t, Jˆ7.8Hz),
2.07 (2H, t, Jˆ7.8Hz), 1.74±1.62 (4H, m), 0.89 (9H, s),
0.04 (6H, s); 13C NMR d 149.0, 109.2, 62.8, 62.7, 32.4,
32.1, 30.9, 30.7, 25.9, 18.3, 25.3; MS m/z 201 (M12tBu,
28). Anal. Calcd for C14H30O2Si: C, 65.06; H, 11.70. Found:
C, 64.75; H, 11.95.
1.1.2. 9-'tert-Butyldimethylsiloxy)-6-methylene-1-phenyl-
non-1-yn-3-ol '9). A solution of DMSO (0.80 mL,
11.3 mmol) in CH2Cl2 (4.00 mL) was added to a solution
of oxalyl chloride (0.49 mL, 5.63 mmol) in CH2Cl2
(20.0 mL) at 2788C over a period of 5 min. After the
mixture was stirred for 30 min, a solution of the alcohol 8
(726 mg, 2.81 mmol) in CH2Cl2 (4.00 mL) was added to the
CH2Cl2 solution, and the reaction mixture was stirred at the
same temperature for 1.5 h. Et3N (3.92 mL, 28.1 mmol) was
then added to the reaction mixture, which was gradually
warmed to room temperature over a period of 1 h and
diluted with CH2Cl2. The CH2Cl2 solution was washed
with water and brine, dried, and concentrated to leave the
crude aldehyde. The crude aldehyde was used directly for
the next reaction. To a solution of phenylacetylene
In summary, we have described here an alternative appli-
cation of the Nicholas reaction to ring construction with
which the 1-oxaspiro[4.4]nonane, 1-oxaspiro[4.5]decane,
6-oxaspiro[4.5]decane, and 1-oxaspiro[5.5]undecane frame-
works were ef®ciently constructed by taking advantage
of the propynyl cation species generated from alkyne±
Co2(CO)6 complexes. Further studies on the scope and
limitations of the endo-mode cyclization of alkyne±
Co2(CO)6 are now in progress.
n
(0.34 mL, 3.09 mmol) in THF (24.0 mL) was added BuLi
(1.42 M hexane solution, 2.20 mL, 3.09 mmol) at 08C, and
the reaction mixture was stirred for 30 min. A solution of the
crude aldehyde in THF (4.00 mL) was then added to a solu-
tion of the acetylide in THF solution thus adjusted at 08C,
and stirring was continued for 1 h. The reaction mixture was
quenched by addition of saturated aqueous NH4Cl and
extracted with AcOEt. The extract was washed with water
and brine, dried, and concentrated to dryness. The residue
was chromatographed with hexane±AcOEt (20:1) to give 9
1. Experimental
1.1. General
Infrared spectra were measured with a Shimazu IR-460
spectrometer in CHCl3, mass spectra with a Hitachi M-80
mass spectrometer, 1H NMR spectra with JEOL JNM-
EX270 and JNM-GSX500 spectrometers for samples in
CDCl3, using either tetramethylsilane (for compounds
without a silyl group) or CHCl3 (7.26 ppm)(for compounds
with a silyl group) as an internal standard, and 13C NMR
spectra with JEOL JNM-EX270 and JNM-GSX500 spectro-
meters in CDCl3 with CDCl3 (77.00 ppm) as an internal
reference. All reactions were carried out under a nitrogen
atmosphere otherwise stated. Silica gel (Silica gel 60, 230±
400 mesh, Merck) was used for chromatography. Organic
1
(491 mg, 49%) as a colorless oil: IR 3412, 1645 cm21; H
NMR d 7.44±7.30 (5H, m), 4.81 (1H, s), 4.80 (1H, s), 4.62
(1H, t, Jˆ6.4 Hz), 3.62 (2H, t, Jˆ6.4 Hz), 2.27 (2H, t, Jˆ
7.3 Hz), 2.11 (2H, t, Jˆ7.3 Hz), 1.97±1.92 (2H, m), 1.71±
1.58(2H, m), 0.89 (9H, s), 0.04 (6H, s); 13C NMR d 148.5,
131.7, 128.4, 128.3, 122.6, 109.6, 89.9, 85.1, 62.8, 62.7,
35.9, 32.3, 31.6, 30.9, 26.0, 18.3, 25.3; MS m/z 301
(M12tBu, 1.3). Anal. Calcd for C22H34O2Si: C, 73.69; H,
9.56. Found: C, 73.31; H, 9.71.
extracts were dried over anhydrous SO4.
2
1.1.3. Hexacarbonyl-m-[h4-3-methoxy-6-methylene-1-
phenylnon-1-yn-9-ol]dicobalt'Co±Co) '11). To a solution
of 9 (1.00 g, 2.79 mmol) in THF (28.0 mL) was added NaH
(134 mg, 3.35 mmol) and MeI (1.04 mL, 16.7 mmol) at 08C.
The reaction mixture was stirred at 08C for 30 min and then
at room temperature for 1 h, quenched by addition of water,
and extracted with AcOEt. The extract was washed with
water and brine, dried, and concentrated to leave 10.
TBAF (1.00 M THF solution, 3.10 mL, 3.10 mmol) was
added to a solution of the crude 10 in THF (28.0 mL) and
the mixture was stirred at room temperature for 30 min.
THF was evaporated off and the resulting oil was dissolved
in Et2O (28.0 mL). Co2(CO)8 (1.08g, 4.18mmol) was
added to the Et2O solution and the mixture was stirred at
room temperature for 30 min. Et2O was evaporated off and
1.1.1. 7-'tert-Butyldimethylsiloxy)-4-methyleneheptan-1-
ol '8). To a suspension of BuOK (3.45 g, 30.8mmol) in
t
THF (41.0 mL) was added methyltriphenylphosphonium
bromide (11.0 g, 30.8mmol) at 0 8C and the THF solution
was stirred for 15 min. A solution of 7 (3.90 g, 10.3 mmol)
in THF (10.0 mL) was added to this THF solution of the
resulting methylenetriphenylphosphorane at room tempera-
ture. After being stirred for 1 h, the reaction mixture was
quenched by addition of saturated aqueous NH4Cl and
extracted with Et2O. The extract was washed with water
and brine, dried, and concentrated to dryness. The residue
was taken up in a combined solution of CH2Cl2 and H2O
(20:1, 50.0 mL), to which was added DDQ (3.49 g,
15.4 mmol). The reaction mixture was stirred at room
temperature and quenched by addition of saturated aqueous

C. Mukai et al. / Tetrahedron 58 *2002) 2755±2762
2759
the residue was chromatographed with hexane±AcOEt (3:1)
to give 11 (1.26 g, 83%) as a reddish brown oil: IR 2091,
2054, 2029 cm21; 1H NMR d 7.50±7.26 (5H, m), 4.82 (1H,
s), 4.78(1H, s), 4.53 (1H, t, Jˆ6.4 Hz), 3.67±3.61 (2H, m),
3.51 (3H, s), 2.39±2.19 (2H, m), 2.13±2.04 (2H, m), 1.98±
1.90 (2H, m), 1.74±1.64 (2H, m); 13C NMR d 199.5, 148.2,
137.9, 129.4, 128.8, 127.7, 109.8, 98.5, 91.7, 81.3, 65.8,
62.5, 59.0, 36.1, 32.4, 30.7; MS m/z 544 (M1, 5.6). Anal.
Calcd for C23H22Co2O8: C, 50.75; H, 4.07. Found: C, 50.63;
H, 4.20.
1.2.3. '5Rp,7Sp)-7-Phenylethynyl-1-oxaspiro[4.4]nonane
'14). CAN (103 mg, 1.87£1021 mmol) was added to a
solution of 13a (23.9 mg, 4.67£1022 mmol) in acetone
(4.70 mL) at 08C. After being stirred for 15 min, the reaction
mixture was concentrated, diluted with water, and extracted
with AcOEt. The extract was washed with water and brine,
dried, and concentrated to dryness. The residue was
chromatographed with hexane±AcOEt (40:1) to give 14
1
(9.50 mg, 90%) as a colorless oil: H NMR d 7.39±7.26
(5H, m), 3.82±3.77 (2H, m), 3.12 (1H, m), 2.22±2.17
(2H, m), 1.95±1.72 (8H, m); 13C NMR d 131.5, 128.1,
127.5, 124.6, 94.1, 90.5, 80.3, 66.7, 45.7, 37.5, 36.2, 32.3,
29.2, 25.9; MS m/z 226 (M1, 91). Anal. Calcd for C16H18O:
C, 84.91; H, 8.02. Found: C, 84.56; H, 8.11.
1.1.4.
Hexacarbonyl-m-[h4-3-acetoxy-6-methylene-1-
phenylnon-1-yn-9-ol]dicobalt'Co±Co) '12). A solution
of 9 (720 mg, 2.01 mmol), DMAP (736 mg, 6.03 mmol),
and Ac2O (0.28mL, 3.02 mmol) in CH 2Cl2 (20.0 mL) was
allowed to stand at 08C for 30 min. The mixture was washed
with water and brine, dried, and concentrated to leave the
crude acetate. According to the procedure described for the
preparation of 11, this crude acetate was successively
treated with TBAF and Co2(CO)8 to afford, after puri®cation
by chromatography with hexane±AcOEt (3:1), 12 (948mg,
82%) as a reddish brown oil: IR 2093, 2056, 2025,
1.2.4. '5Rp,7Sp)-7-'2-Phenylquinoxalin-3-yl)-1-oxaspiro-
[4.4]nonan-2-one '15). RuO2´(H2O)n (5.90 mg, 0.45£1021
mmol) and NaIO4 (715 mg, 3.35 mmol) was added to a two-
phase solution of 14 (50.5 mg, 2.23£1021 mmol) in CCl4
(0.50 mL), CH3CN (0.50 mL), and water (0.90 mL) under
vigorous stirring. Stirring was continued for 12 h at room
temperature. The reaction mixture was diluted with water
and extracted with AcOEt. The extract was washed with
water and brine, dried, and concentrated to dryness. The
crude lactone derivative was dissolved in CH2Cl2
(2.20 mL), to which o-phenylenediamine (28.9 mg,
0.27 mmol) was added. The reaction mixture was stirred
at room temperature for 15 min, diluted with water, and
extracted with CH2Cl2. The extract was washed with
water and brine, dried, and concentrated to dryness.
Chromatography of the residue with hexane±AcOEt (3:1)
gave 15 (41.0 mg, 53%) as a colorless oil: IR 1763 cm21; 1H
NMR d 8.12±8.04 (2H, m), 7.76±7.71 (2H, m), 7.57±7.50
(5H, m), 3.99 (1H, tt, Jˆ8.8, 7.5 Hz), 2.66±2.60 (2H, m),
2.57±1.99 (8H, m); 13C NMR d 176.5, 157.9, 154.9, 141.4,
140.7, 139.7, 129.7, 129.5, 129.2, 129.1, 128.7, 128.6, 128.5,
95.3, 45.1, 41.8, 38.3, 32.2, 32.0, 29.8; MSm/z 344 (M1, 0.2).
HRMS calcd for C22H20N2O2 344.1525, found 344.1522.
1
1733 cm21; H NMR d 7.47±7.28(5H, m), 6.40 (1H, m),
4.81 (1H, s), 4.74 (1H, s), 3.65±3.61 (2H, m), 2.20±1.96
(6H, m), 2.14 (3H, s), 1.68±1.65 (2H, m); 13C NMR d 198.8,
170.5, 147.4, 137.4, 129.4, 128.9, 128.0, 110.0, 96.2, 90.5,
73.8, 62.5, 35.5, 32.4, 32.2, 30.6, 20.7; MS m/z 571 (M121,
3.5). Anal. Calcd for C24H22Co2O9: C, 50.37; H, 3.87.
Found: C, 50.20; H, 3.97.
1.2. Ring closure of 11, 12, 20, 27, and 30 with SnCl4
A solution of SnCl4 in CH2Cl2 (0.10 M solution; 2.36 mL,
2.36£1021 mmol) was added to a solution of 12 (67.5 mg,
1.18£1021 mmol), in CH2Cl2 (11.8mL) at 0 8C for 30 min.
The reaction mixture was stirred for 1 h and quenched by
addition of water. The CH2Cl2 layer was separated, washed
with water and brine, dried, and concentrated to dryness.
Chromatography with hexane±AcOEt (100:1) afforded
13a (41.6 mg, 72%) and 13b (6.50 mg, 11%). Treatment
of 11 with SnCl4 also gave a mixture of 13a and 13b.
Similar treatment of 20, 27, and 31 with SnCl4 gave the
corresponding oxaspiro derivatives 32, 33, and 34, respec-
tively. Chemical yields and ratio of diastereoisomers are
summarized in Schemes 2 and 5.
1.2.5. '10Rp,30Sp)-2-[10-'100-tert-Butyldiphenylsiloxy)pro-
pyl-10-trimethylsiloxycyclopent-30-yl]-3-phenylquinoxa-
line '16). To a solution of 15 (33.5 mg, 0.97£1021 mmol) in
Et2O (1.00 mL) was added LiAlH4 (5.50 mg, 1.46£1021
mmol) at 08C. The reaction mixture was stirred at the
same temperature for 30 min and quenched by addition of
water. The precipitates were ®ltered off and the ®ltrate
was dried and concentrated. The crude diol derivative was
dissolved in DMF (0.10 mL), to which TBDPSCl (40.0 mg,
1.46£1021 mmol) and imidazole (19.8mg, 0.29 mmol).
The reaction mixture was stirred at room temperature for
1 h, diluted with water, and extracted with Et2O. The extract
was washed with water and brine, dried, and concentrated to
dryness. A solution of the crude product thus prepared and
TMS±imidazole (20.5 mg, 1.46£1021 mmol) in CH2Cl2
(1.00 mL) was allowed to stand for 10 min at room tempera-
ture. The reaction mixture was diluted with water and
extracted with CH2Cl2. The extract was washed with
water and brine, dried, and concentrated to dryness. Chroma-
tography of the residue with hexane±AcOEt (8:1) gave 16
1.2.1. Hexacarbonyl-m-[h4-'5Rp,7Sp)-7-phenylethynyl-1-
oxaspiro[4.4]-nonane]dicobalt'Co±Co) '13a). A reddish
1
brown oil: IR 2090, 2050, 2023 cm21; H NMR d 7.56±
7.29 (5H, m), 3.85±3.80 (2H, m), 3.52 (1H, m), 2.40±1.70
(10H, m); 13C NMR d 199.8, 138.2, 129.4, 128.8, 127.7,
104.3, 91.7, 90.8, 66.9, 47.7, 42.7, 38.0, 36.0, 34.0, 25.9;
MS m/z 512 (M1, 0.8). HRMS calcd for C22H18Co2O7
511.9717, found 511.9707.
1.2.2. Hexacarbonyl-m-[h4-'5Rp,7Rp)-7-phenylethynyl-1-
oxaspiro[4.4]-nonane]dicobalt'Co±Co) '13b). A reddish
1
brown oil: IR 2090, 2050, 2023 cm21; H NMR d 7.39±
1
7.26 (5H, m), 3.84±3.77 (2H, m), 3.11 (1H, m), 2.24±2.17
(2H, m), 1.95±1.72 (8H, m); MS m/z 512 (M1, 1.5). Anal.
Calcd for C22H18Co2O7: C, 51.59; H, 3.54. Found: C, 51.70;
H, 3.76.
(50.5 mg, 79%) as a colorless oil: H NMR d 8.12±8.05
(2H, m), 7.74±7.34 (17H, m), 3.90 (1H, m), 3.69 (2H, t,
Jˆ5.4 Hz), 2.12±1.89 (6H, m), 1.82±1.64 (4H, m), 1.06
(9H, s), 20.02 (9H, s); 13C NMR d 159.2, 155.1, 141.6,

2760
C. Mukai et al. / Tetrahedron 58 *2002) 2755±2762
140.4, 139.1, 139.0, 135.6, 134.1, 129.5, 129.2, 129.1,
128.9, 128.8, 128.6, 128.5, 127.6, 85.8, 64.5, 47.2, 42.0,
39.6, 37.7, 31.8, 28.3, 26.9, 19.2, 2.1; FABMS m/z
659 (M111, 11). FABHRMS calcd for C41H51N2O2Si2
659.3489, found 659.3499.
tion of 19 (602 mg, 1.51 mmol) in MeOH (15.0 mL) was
added PPTS (38.9 mg, 1.51£1021 mmol) and the reaction
mixture was allowed to stand at room temperature for 1 day.
MeOH was evaporated off and the residue was diluted with
water, and extracted with AcOEt. The extract was washed
with water and brine, dried, and concentrated to dryness.
According to the procedure described for conversion of 10
to 11, the crude hydroxy compound was treated with
Co2(CO)8 (775 mg, 2.23 mmol) to give 20 (843 mg, 93%)
as a reddish brown oil: IR 2093, 2058, 2031, 1734 cm21; 1H
NMR d 7.49±7.32 (5H, m), 6.41 (1H, t, Jˆ6.6 Hz), 4.72
(1H, s), 4.68(1H, s), 3.64 (2H, dt, Jˆ10.9, 5.9 Hz), 2.13
(3H, s), 2.08±1.96 (4H, m), 1.89±1.81 (2H, m), 1.63±1.43
(6H, m); 13C NMR d 198.9, 170.6, 148.5, 137.4, 129.4,
128.9, 127.9, 109.7, 96.4, 90.5, 73.9, 62.7, 37.0, 35.5,
35.2, 32.4, 24.1, 23.8, 20.6; MS m/z 516 (M1284, 21).
Anal. Calcd for C26H26Co2O9: C, 52.02; H, 4.37. Found:
C, 51.82; H, 4.50.
1.2.6. 9-Tetrahydropyranyloxy-5-methylenenonan-1-ol
'18). To a solution of 17 (7.64 g, 49.5 mmol) in THF
(145 mL) was added nBuLi (1.34 M hexane solution,
36.9 mL, 49.5 mmol) at 08C, and the reaction mixture was
stirred for 30 min. A solution of d-valerolactone (4.95 g,
49.5 mmol) in THF (20.0 mL) was then added to a solution
of the acetylide in THF solution thus adjusted at 08C over a
period of 20 min, and stirring was continued for 30 min. The
reaction was quenched by addition of saturated aqueous
NH4Cl, extracted with AcOEt, dried, and concentrated. A
solution of the crude adduct in AcOEt (165 mL) in the
presence of 5% Pd±C (760 mg) was hydrogenated under
hydrogen atmosphere for 1 h. The catalyst was ®ltered
off and the ®ltrated was concentrated to leave the crude
nonanone derivative. According to the procedure described
for conversion of 7 to 8, this compound was exposed to
methylenetriphenylphosphorane, prepared from tBuOK
(16.6 g, 148.5 mmol) and methyltriphenylphosphonium
bromide (53.0 g, 148.5 mmol), to give 18 (7.36 g, 58%) after
puri®cation by chromatography with hexane±AcOEt (3:1).
1.2.9. 8-'tert-Butyldimethylsiloxy)-1-'4-methoxyphenyl-
oxy)octan-4-one '22). According to the procedure
described for preparation of 18, d-valerolactone (3.39 g,
33.9 mmol) was treated with the acetylide, derived from
n
21 (6.56 g, 37.3 mmol) and BuLi (1.58M hexane solu-
tion, 23.6 mL, 37.3 mmol), and the resulting acetylenic
compound was hydrogenated in the presence of 5% Pd±C.
The residue was dissolved in DMF (17.0 mL), to which a
solution of imidazole (5.54 g, 81.3 mmol) and TBSCl
(6.13 g, 40.7 mmol) in DMF (17.0 mL) was added. The
reaction mixture was stirred at room temperature for 1 h,
diluted with water, and extracted with AcOEt. The extract
was washed with water and brine, dried, and concentrated to
dryness. Chromatography of the residue with hexane±
AcOEt (9:1) gave 22 (5.91 g, 45%) as a colorless oil: IR
1710 cm21; 1H NMR d 7.30±7.25 (2H, m), 6.93±6.88 (2H,
m), 4.44 (2H, s), 3.84 (3H, s), 3.66 (2H, t, Jˆ6.3 Hz), 3.48
(2H, t, Jˆ6.3 Hz), 2.53 (2H, t, Jˆ7.3 Hz), 2.45 (2H, t,
Jˆ7.3 Hz), 1.95±1.85 (2H, m), 1.73±1.47 (4H, m), 0.92
(9H, s), 0.08(6H, s); 13C NMR d 210.7, 159.1, 130.5,
129.2, 113.7, 72.5, 69.0, 62.8, 55.2, 42.6, 39.3, 32.2, 25.9,
23.8, 20.3, 18.3, 25.4; FABMS m/z 395 (M111, 0.6). Anal.
Calcd for C22H38O4Si: C, 66.96; H, 9.71. Found: C, 66.72;
H, 9.78.
1
Compound 18 was a colorless oil: IR 3449, 1643 cm21; H
NMR d 4.75 (2H, s), 4.58(1H, dd, Jˆ4.4, 2.9 Hz), 3.87 (1H,
ddd, Jˆ11.2, 7.3, 2.9 Hz), 3.75 (1H, dt, Jˆ 9.8, 6.8 Hz), 3.66
(2H, t, Jˆ6.4 Hz), 3.50 (1H, m), 3.40 (1H, dt, Jˆ9.8, 6.4 Hz),
2.04 (4H, t, Jˆ7.4 Hz), 1.86±1.42 (14H, m); 13C NMR d
149.3, 109.0, 98.7, 67.4, 62.6, 62.2, 35.6, 32.4, 30.7, 29.3,
25.4, 24.3, 23.8, 19.5; FABMS m/z 257 (M111, 2.0).
FABHRMS calcd for C15H29O3 257.2117, found 257.2124.
1.2.7. 3-Acetoxy-11-tetrahydropyranyloxy-7-methylene-
1-phenylundec-1-yne '19). Sulfur trioxide pyridine com-
plex (1.53 g, 9.60 mmol) was added to a solution of 18
(612 mg, 2.40 mmol), DMSO (4.80 mL, 67.6 mmol), and
Et3N (1.67 mL, 12.0 mmol) in CH2Cl2 (24.0 mL) at 08C.
The reaction mixture was stirred for 30 min at the same
temperature, quenched by addition of water, and extracted
with CH2Cl2. The extract was washed with water and brine,
dried, and concentrated to dryness. According to the pro-
cedure described for conversion of 8 to 12, the crude
aldehyde was successively exposed to the acetylide,
prepared from phenylacetylene (0.40 mL, 3.60 mmol) and
nBuLi (1.44 M, hexane solution, 2.50 mL, 3.60 mmol), and
acetylation conditions (Ac2O (0.34 mL, 3.60 mmol), DMAP
(880 mg, 7.20 mmol)) to produce 19 (918mg, 96%) as a
1.2.10. 8-'tert-Butyldimethylsiloxy)-1-'4-methoxyphenyl-
oxy)-4-methyleneoctane '23). According to the procedure
described for conversion of 7 to 8, 23 (2.91 g, 93%) was
obtained from 22 (3.17 g, 8.02 mmol). Compound 23 was a
colorless oil: IR 1643 cm21; 1H NMR d 7.28±7.25 (2H, m),
6.89±6.87 (2H, m), 4.71 (2H, s), 4.43 (2H, s), 3.81 (3H, s),
3.61 (2H, t, Jˆ6.4 Hz), 3.45 (2H, t, Jˆ6.4 Hz), 2.07 (2H, t,
Jˆ7.8Hz), 2.02 (2H, t, Jˆ7.8Hz), 1.77±1.71 (2H, m),
1.56±1.43 (4H, m), 0.89 (9H, s), 0.05 (6H, s); 13C NMR d
159.0, 149.0, 130.7, 129.1, 113.7, 108.9, 72.5, 69.7, 62.9,
55.1, 35.7, 32.4, 32.4, 27.8, 25.9, 23.9, 18.3, 25.4; MS m/z
392 (M1, 0.3). Anal. Calcd for C23H40O3Si: C, 70.35; H,
10.27. Found: C, 70.11; H, 10.39.
1
colorless oil: IR 1736, 1643 cm21; H NMR d 7.45±7.28
(5H, m), 5.61 (1H, t, Jˆ6.6 Hz), 4.76 (2H, s), 4.57 (1H, t,
Jˆ3.0 Hz), 3.86 (1H, dd, Jˆ10.9, 3.6 Hz), 3.74 (1H, dd, Jˆ
9.9, 6.6 Hz), 3.49 (1H, m), 3.39 (1H, dt, Jˆ9.9, 6.6 Hz),
2.11 (3H, s), 2.09±1.51 (18H, m); 13C NMR d 169.9,
148.7, 131.8, 128.5, 128.2, 122.2, 109.5, 98.7, 86.4, 85.2,
67.3, 64.4, 62.2, 35.6, 35.2, 34.4, 30.7, 29.4, 25.4, 24.3,
23.0, 21.0, 19.6; FABMS m/z 399 (M111, 0.6). Anal.
Calcd for C25H34O4: C, 75.34; H, 8.60. Found: C, 75.24;
H, 8.77.
1.2.11. 8-'tert-Butyldimethylsiloxy)-4-methyleneoctan-1-
ol '24). According to the procedure described for conversion
of 7 to 8, 24 (938mg, 91%) was obtained from 23 (1.49 g,
3.79 mmol). Compound 24 was a colorless oil: IR 3456,
1.2.8.
phenylundec-1-yn-11-ol]dicobalt'Co±Co) '20). To a solu-
Hexacarbonyl-m-[h4-3-acetoxy-7-methylene-1-
1
1643 cm21; H NMR d 4.75 (1H, s), 4.74 (1H, s), 3.66

C. Mukai et al. / Tetrahedron 58 *2002) 2755±2762
2761
(2H, t, Jˆ6.4 Hz), 3.61 (2H, t, Jˆ6.4 Hz), 2.09 (2H, t, Jˆ
7.3 Hz), 2.04 (2H, t, Jˆ7.8Hz), 1.71 (2H, tt, Jˆ7.3, 6.4 Hz),
1.55±1.43 (4H, m), 0.89 (9H, s), 0.05 (6H, s); 13C NMR d
159.0, 149.0, 130.7, 129.1, 113.7, 108.9, 72.5, 69.7, 62.9,
55.1, 35.7, 32.4, 32.4, 27.8, 25.9, 23.9, 18.3, 25.4; FABMS
m/z 273 (M111, 12). FABHRMS calcd for C15H33O2Si
273.2250, found 273.2256.
28 (2.00 g, 7.18mmol). Compound 29 was a colorless oil:
IR 3402, 1646 cm21; 1H NMR d 7.44±7.24 (7H, m), 6.90±
6.85 (2H, m), 4.75 (2H, s), 4.60 (1H, dd, Jˆ11.9, 6.3 Hz),
4.42 (2H, s), 3.80 (3H, s), 3.45 (2H, t, Jˆ6.3 Hz), 2.10 (4H,
t, Jˆ7.6 Hz), 1.86±1.61 (6H, m); 13C NMR d 159.0, 148.6,
131.6, 130.5, 129.1, 128.2, 128.1, 122.6, 113.7, 109.3, 90.2,
84.7, 72.4, 69.6, 62.6, 55.1, 37.3, 35.5, 32.3, 27.7, 23.1; MS
m/z 378(M 1, 0.9). Anal. Calcd for C25H30O3: C, 79.33; H,
7.99. Found: C, 79.49; H, 8.26.
1.2.12.
10-'tert-Butyldimethylsiloxy)-6-methylene-1-
phenyldec-1-yn-3-ol '25). According to the procedure
described for the preparation of 9, 25 (5.20 g, 55%) was
obtained from 24 (6.95 g, 25.5 mmol). Compound 25 was
a colorless oil: IR 3453, 1684 cm21; 1H NMR d 7.44±7.29
(5H, m), 4.81 (1H, s), 4.78 (1H, s), 4.62 (1H, t, Jˆ6.4 Hz),
3.62 (2H, t, Jˆ6.4 Hz), 2.26 (2H, t, Jˆ7.8Hz), 2.07 (2H, t,
Jˆ7.3 Hz), 1.97±1.92 (2H, m), 1.55±1.48(4H, m), 0.90
(9H, s), 0.05 (6H, s); 13C NMR d 148.8, 131.6, 128.4,
128.2, 122.6, 109.5, 89.9, 85.1, 63.0, 62.6, 35.9, 35.8,
32.5, 31.5, 26.0, 23.9, 18.3, 25.3; MS m/z 372 (M1, 0.5).
Anal. Calcd for C23H36O2Si: C, 74.14; H, 9.74. Found: C,
73.84; H, 10.01.
1.2.17. 3-Acetoxy-7-methylene-1-phenyldec-1-yn-10-ol
'30). According to the procedure described for acetylation
and debenzylation (25 to 26 and 23 to 24), 30 (635 mg,
80%) was obtained from 29 (1.00 g, 2.64 mmol). Com-
pound 30 was a colorless oil: IR 3444, 1733, 1644 cm21
;
1H NMR d 7.47±7.43 (5H, m), 5.62 (1H, t, Jˆ6.4 Hz), 4.79
(1H, s), 4.78(1H, s), 3.68±3.64 (2H, m), 2.12±2.10 (4H, m),
2.11 (3H, s), 1.88±1.60 (6H, m); 13C NMR d 170.0, 148.4,
131.8, 128.5, 128.2, 122.2, 109.7, 86.4, 85.3, 64.3, 62.5,
35.3, 34.3, 32.0, 30.6, 22.9, 21.0; MS m/z 300 (M1, 8.7).
Anal. Calcd for C19H24O3: C, 75.97; H, 8.05. Found: C,
75.68; H, 8.19.
1.2.13. 3-Acetoxy-6-methylene-1-phenyldec-1-yn-10-ol
'26). According to the procedure described for the prepa-
ration of 12, 26 (52.2 mg, 57%) was obtained from 25
(112 mg, 0.29 mmol). Compound 26 was a colorless oil:
1.2.18. Hexacarbonyl-m-[h4-3-acetoxy-7-methylene-1-
phenyldec-1-yn-10-ol]dicobalt'Co±Co) '31). According
to the procedure described for the preparation of 12, 31
(139 mg, 88%) was obtained from 30 (80.7 mg, 0.27
mmol). Compound 31 was a reddish brown oil: IR 2093,
2056, 2025, 1732 cm21; 1H NMR d 7.48±7.31 (5H, m), 6.40
(1H, dd, Jˆ7.8, 5.3 Hz), 4.79 (1H, s), 4.70 (1H, s), 3.65±
3.61 (2H, m), 2.14 (3H, s), 2.09±2.03 (4H, m), 1.87±1.57
(6H, m); 13C NMR d 198.9, 170.6, 148.3, 137.4, 129.4,
128.9, 127.9, 109.9, 96.4, 90.5, 73.9, 62.7, 37.1, 35.3,
32.0, 30.7, 24.1, 20.7; MS m/z 530 (M1256, 0.8). Anal.
Calcd for C25H24Co2O9: C, 51.21; H, 4.13. Found: C,
50.93; H, 4.19.
1
IR 3460, 1734 cm21; H NMR d 7.45±7.28(5H, m), 5.60
(1H, t, Jˆ6.8Hz), 4.76 (1H, s), 4.75 (1H, s), 3.66 (2H, t,
Jˆ6.8Hz), 2.12±2.05 (4H, m), 2.11 (3H, s), 1.89±1.45 (6H,
m); 13C NMR d 170.0, 147.8, 131.8, 128.6, 128.2, 122.2,
109.9, 86.3, 85.5, 64.2, 62.8, 35.7, 33.0, 32.4, 31.3, 23.8,
21.0; MS m/z 300 (M1, 5.2). HRMS calcd for C19H24O3
300.1725, found 300.1730.
1.2.14. Hexacarbonyl-m-[h4-3-acetoxy-6-methylene-1-
phenyldec-1-yn-10-ol]dicobalt'Co±Co) '27). According
to the procedure described for the preparation of 12, 27
(271 mg, 92%) was obtained from 26 (150 mg, 0.50
mmol). Compound 27 was a reddish brown oil: IR 2093,
2056, 2025, 1734 cm21; 1H NMR d 7.48±7.28(5H, m), 6.39
(1H, t, Jˆ6.3 Hz), 4.78(1H, s), 4.72 (1H, s), 3.66±3.60 (2H,
m), 2.19±1.94 (6H, m), 2.13 (3H, s), 1.62±1.37 (4H, m); 13C
NMR d 198.8, 170.5, 147.7, 137.4, 129.4, 128.9, 127.9,
109.8, 96.3, 90.5, 73.8, 62.7, 35.9, 35.5, 32.3, 32.2, 23.8,
20.7; MS m/z 586 (M1, 3.3). Anal. Calcd for C25H24Co2O9:
C, 51.21; H, 4.13. Found: C, 51.06; H, 4.21.
1.2.19. Hexacarbonyl-m-[h4-'6Rp,8Sp)-8-phenylethynyl-
1-oxaspiro[5.5]-undecane]dicobalt'Co±Co) '32a).
A
reddish brown oil: IR 2087, 2050, 2023 cm21; H NMR d
7.54±7.26 (5H, m), 3.73±3.59 (2H, m), 3.31 (1H, tt, Jˆ
11.9, 3.3 Hz), 2.48±2.43 (1H, m), 2.14±1.98 (2H, m),
1.91±1.09 (11H, m); 13C NMR d 200.0, 138.4, 129.2,
128.8, 127.5, 106.5, 91.5, 71.9, 60.8, 42.2, 37.0, 36.4,
35.3, 34.8, 26.1, 21.0, 18.9; FABMS m/z 541 (M111,
0.8). FABHRMS calcd for C24H23Co2O7 541.0108, found
541.0089.
1
1.2.15. 1-'4-Methoxyphenyloxy)-4-methyleneoctan-8-ol
'28). According to the procedure described for the prepa-
ration of 10, 28 (5.44 g, 98%) was obtained from 23 (7.85 g,
20.0 mmol). Compound 28 was a colorless oil: IR 3421,
1.2.20. Hexacarbonyl-m-[h4-'6Rp,8Rp)-8-phenylethynyl-
1-oxaspiro[5.5]-undecane]dicobalt'Co±Co) '32b).
A
reddish brown oil: IR 2089, 2050, 2023 cm21; H NMR d
7.52±7.30 (5H, m), 3.74±3.70 (2H, m), 3.03 (1H, tt, Jˆ
11.9, 3.3 Hz), 2.40 (1H, m), 2.12±2.03 (2H, m), 1.88±
1.25 (11H, m); 13C NMR d 199.7, 138.3, 129.2, 128.8,
127.6, 10.5.1, 91.1, 73.1, 61.2, 44.4, 38.5, 35.4, 35.2, 31.4,
26.2, 22.6, 19.1; FABMS m/z 541 (M111, 0.7). FABHRMS
calcd for C24H23Co2O7 541.0108, found 541.0140.
1
1645 cm21 1H NMR d 7.28±7.25 (2H, m), 6.89±6.86
;
(2H, m), 4.72 (2H, s), 4.43 (2H, s), 3.80 (3H, s), 3.65 (2H,
t, Jˆ6.4 Hz), 3.45 (2H, t, Jˆ6.4 Hz), 2.08(2H, t, Jˆ7.8Hz),
2.04 (2H, t, Jˆ7.3 Hz), 1.77±1.71 (2H, m), 1.59±1.46 (4H,
m); 13C NMR d 159.0, 158.9, 148.9, 130.6, 129.2, 113.7,
109.1, 72.5, 69.7, 62.6, 55.2, 35.7, 32.3, 27.8, 23.8; MS m/z
278(M 1, 9.9). Anal. Calcd for C17H26O3: C, 73.34; H, 9.41.
Found: C, 72.97; H, 9.69.
1.2.21. Hexacarbonyl-m-[h4-'2Rp,5Sp)-2-phenylethynyl-
6-oxaspiro[4.5]-decane]dicobalt'Co±Co) '33a). A reddish
brown oil: IR 2087, 2050, 2023 cm21; 1H NMR d 7.56±7.30
(5H, m), 3.74±3.45 (3H, m), 2.29 (1H, m), 2.20±2.02 (2H,
m), 1.98±1.80 (2H, m), 1.73±1.43 (7H, m); 13C NMR 199.8,
1.2.16. 10-'4-Methoxyphenyloxy)-7-methylene-1-phenyl-
dec-1-yn-3-ol '29). According to the procedure described
for the preparation of 9, 29 (2.29 g, 84%) was obtained from

2762
C. Mukai et al. / Tetrahedron 58 *2002) 2755±2762
138.2, 129.5, 128.8, 127.6, 103.5, 91.4, 82.8, 62.8, 45.9,
43.4, 38.2, 36.2, 34.2, 25.9, 20.8; FABMS m/z 527
(M111, 1.2). Anal. Calcd for C23H20Co2O7: C, 52.49; H,
3.83. Found: C, 52.60; H, 3.90.
References
1. (a) Nicholas, K. M. Acc. Chem. Res. 1987, 20, 307. (b) Dias, D.;
Martin, V. S. J. Org. Chem. 2000, 65, 7896. (c) Dias, D.;
Martin, T.; Martin, V. S. Org. Lett. 2001, 3, 3289. (d) Liu,
T.-Z.; Isobe, M. Synlett 2000, 266. (e) Kira, K.; Isobe, M.
Tetrahedron Lett. 2000, 41, 5951.
1.2.22. Hexacarbonyl-m-[h4-'2Rp,5Rp)-8-phenylethynyl-
6-oxaspiro[4.5]-decane]dicobalt'Co±Co) '33b). A reddish
brown oil: IR 2087, 2050, 2023 cm21; 1H NMR d 7.54±7.30
(5H, m), 3.86±3.63 (3H, m), 2.49 (1H, m), 2.34 (1H, m),
2.11±2.00 (1H, m), 1.80 (1H, m), 1.69±1.42 (8H, m); 13C
NMR d 199.8, 138.2, 129.4, 128.8, 127.7, 104.2, 91.7, 83.3,
62.6, 47.2, 42.0, 36.0, 35.8, 33.9, 26.0, 21.0; FABMS m/z
541 (M111, 1.3). Anal. Calcd for C23H20Co2O7: C, 52.49;
H, 3.83. Found: C, 52.82; H, 3.93.
2. (a) Mukai, C.; Ikeda, Y.; Sugimoto, Y.; Hanaoka, M.
Tetrahedron Lett. 1994, 35, 2179. (b) Mukai, C.; Sugimoto,
Y.; Ikeda, Y.; Hanaoka, M. J. Chem. Soc., Chem. Commun.
1994, 1161. (c) Mukai, C.; Sugimoto, Y.; Ikeda, Y.; Hanaoka,
N. Tetrahedron 1998, 54, 823. (d) Mukai, C.; Yamaguchi, S.;
Sugimoto, Y.; Miyakoshi, N.; Kasamatsu, E.; Hanaoka, M.
J. Org. Chem. 2000, 65, 6761. (e) Mukai, C.; Yamaguchi, S.;
Kim, I. J.; Hanaoka, M. Chem. Pharm. Bull. 2001, 49, 613.
3. Mukai, C.; Yamashita, H.; Ichiryu, T.; Hanaoka, M.
Tetrahedron 2000, 56, 2203.
1.2.23. Hexacarbonyl-m-[h4-'5Rp,7Sp)-7-phenylethynyl-
1-oxaspiro[4.5]-decane]dicobalt'Co±Co) '34a). A reddish
brown oil: IR 2089, 2050, 2023 cm21; 1H NMR d 7.53±7.29
(5H, m), 3.93±3.82 (2H, m), 3.39 (1H, tt, Jˆ12.2, 3.3 Hz),
2.12±1.64 (8H, m), 1.45±1.26 (4H, m); 13C NMR d 199.8,
138.4, 129.2, 128.8, 127.6, 106.1, 91.1, 81.6, 66.9, 45.1,
38.3, 38.1, 36.1, 34.6, 25.2; MS m/z 526 (M1, 0.3). Anal.
Calcd for C23H20Co2O7: C, 52.49; H, 3.83. Found: C, 52.59;
H, 3.89.
4. Although several mineral acids were also examined, acceptable
yields were not attained.
5. (a) Seyferth, D.; Nestle, M.; Wehman, O. J. Am. Chem. Soc.
1975, 97, 7417. (b) Montana, A. M.; Nicholas, K. M. J. Org.
Chem. 1988, 53, 5193.
6. (a) Carlsen, P. H. J.; Katsuki, T.; Martin, V. S.; Sharpless, K. B.
J. Org. Chem. 1981, 46, 3937. (b) Smith, III, A. B.;
Scarborough, R. M. Synth. Commun. 1980, 10, 205.
7. Christl, M.; Kraft, A. Angew. Chem., Int. Ed. Engl. 1988, 27,
1369.
1.2.24. Hexacarbonyl-m-[h4-'5Rp,7Rp)-7-phenylethynyl-
1-oxaspiro[4.5]-decane]dicobalt'Co±Co) '34b). A reddish
brown oil: IR 2089, 2050, 2023 cm21; 1H NMR d 7.50±7.30
(5H, m), 3.92±3.80 (2H, m), 2.97 (1H, tt, Jˆ11.9, 3.0 Hz),
2.08±1.23 (12H, m); 13C NMR d 199.7, 138.3, 129.2, 128.8,
127.6, 104.7, 91.2, 82.9, 66.5, 46.4, 40.6, 36.9, 34.7, 34.4,
26.1; FABMS m/z 527 (M111, 1.1). Anal. Calcd for
C23H20Co2O7: C, 52.49; H, 3.83. Found: C, 52.72; H, 4.04.
8. Stereochemistries of 32, 33, and 34 were tentatively assigned by
1
comparison of their H NMR spectra to that of 13.