Ruthenium-Catalyzed Polycyclization Reactions

Article abstract of DOI:10.1021/jo972279g

The application of ruthenium alkylidenes such as 1 to the catalysis of polycyclization reactions is reported. Several acyclic precursors have been synthesized and reacted with 1. These precursors vary in topology and contain acetylenic and/or cycloolefinic metathesis relays. The cyclization reactions proceed in moderate to good yields to produce polycyclic polyenes when the precursors are subjected to catalytic amounts of 1. In general, precursors bearing n relay units generate polycycles containing (n + 1) rings.

Full text of DOI:10.1021/jo972279g

J . Org. Chem. 1998, 63, 4291-4298
4291
Ru th en iu m -Ca ta lyzed P olycycliza tion Rea ction s
William J . Zuercher, Matthias Scholl, and Robert H. Grubbs*
The Arnold and Mabel Beckman Laboratories of Chemical Synthesis, Division of Chemistry and
Chemical Engineering, California Institute of Technology, Pasadena, California 91125
Received December 18, 1997
The application of ruthenium alkylidenes such as 1 to the catalysis of polycyclization reactions is
reported. Several acyclic precursors have been synthesized and reacted with 1. These precursors
vary in topology and contain acetylenic and/or cycloolefinic metathesis relays. The cyclization
reactions proceed in moderate to good yields to produce polycyclic polyenes when the precursors
are subjected to catalytic amounts of 1. In general, precursors bearing n relay units generate
polycycles containing (n + 1) rings.
Sch em e 1
In tr od u ction
Cascade reactions have proven effective in the as-
sembly of complex polycyclic systems from simple acyclic
precursors.1 These cascade cyclizations are characterized
by the formation of a reactive intermediate that under-
goes a series ring-forming steps before termination.
Examples have been reported for cationic,2 anionic,3
radical,4 and transition-metal-mediated cascade pro-
cesses.1 The application of homogeneous transition metal
catalysts to cascade cyclizations of polyenes and polyynes
appears very promising for the synthesis of polycyclic
structures. For example, the groups of Negishi (eq 1)5
and Trost (eq 2)6 have utilized cyclic carbopalladation
cascades in the one-step, catalytic assembly of systems
containing up to seven rings (Scheme 1). Despite tre-
mendous progress in this area, the development of
efficient methods for the construction of polycyclic sys-
tems remains an important goal of synthetic chemistry.
Previous reports from this laboratory7 demonstrate the
possibility of extending catalytic diene ring-closing me-
tathesis8 (RCM, eq 3) to the formation of polycyclic
structures by a cascade of ring-opening olefin metathesis
or carbene-acetylene metathesis reactions.9 For ex-
ample, when a precursor diene containing an acetylene
or a cyclolefin is exposed to ruthenium alkylidene 1,10
bicyclics are produced (eqs 4 and 5). Extending this
reaction to analogous precursors bearing two or more of
these olefin metathesis relays should lead to the produc-
tion of polycyclic molecules. Herein we report the
synthesis of such precursors and their cascade cyclization
reactions catalyzed by 1.
(1) (a) Teitze, L. F. Chem. Rev. 1996, 96, 115-136. (b) Hudlicky, T.
Chem. Rev. 1996, 96, 3-30. (c) Ho, T.-L. Tandem Reactions in Organic
Synthesis; Wiley-Interscience: New York, 1992. (d) Bunce, R. A.
Tetrahedron 1995, 51, 13103-13159.
(2) J ohnson, W. S.; Wiedhaup, K.; Brady, S. F.; Olson, G. L. J . Am.
Chem. Soc. 1974, 96, 3979-3984.
(3) Ihara, M.; Makita, K.; Tokunaga, Y.; Fukumoto, K. J . Org. Chem.
1994, 59, 6008.
(4) Takahashi, T.; Katouda, W.; Sakamoto, Y.; Tomida, S.; Yamada,
H. Tetrahedron Lett. 1995, 36, 2273.
(5) (a) Zhang, Y.; Wu, G.; Agnel, G.; Negishi, E. J . Am. Chem. Soc.
1990, 112, 8590. (b) Negishi, E. Pure Appl. Chem. 1992, 64, 323-334.
(6) Trost, B. M.; Shi, Y. J . Am. Chem. Soc. 1993, 115, 9421-9438.
(7) (a) Kim, S.-H.; Bowden, N. B.; Grubbs, R. H. J . Am. Chem. Soc.
1994, 116, 10801. (b) Kim, S.-H.; Zuercher, W. J .; Bowden, N. B.;
Grubbs, R. H. J . Org. Chem. 1996, 61, 1073-1081. (c) Zuercher, W.
J .; Hashimoto, M.; Grubbs, R. H. J . Am. Chem. Soc. 1996, 118, 6634-
6640.
Resu lts a n d Discu ssion
(8) Recent examples of RCM of R,ω-dienes: (a) Grubbs, R. H.; Chang,
S. B. Tetrahedron 1997, 38, 4757-4760 and references therein. (b)
General RCM: Grubbs, R. H.; Miller, S. J .; Fu, G. C. Acc. Chem. Res.
1995, 28, 446-452 and references therein. General olefin metathesis:
Ivin, K. J .; Mol, J . C. Olefin Metathesis and Metathesis Polymerization;
Academic: San Diego, 1997.
(9) A cascade of diene RCM reactions was employed in the quantita-
tive RCM of poly(1,2-butadiene) to produce a cyclopentene-based
polymer. Coates, G. W.; Grubbs, R. H. J . Am. Chem. Soc. 1996, 118,
230-231.
P r ecu r sor Syn th esis. Several dienes containing two
or more olefin metathesis relay units were prepared in
order to study the possibility of ruthenium-catalyzed
(10) (a) Synthesis: Schwab, P.; Grubbs, R. H.; Ziller, J . W. J . Am.
Chem. Soc. 1996, 118, 100-110. (b) Mechanism and activity: Dias, E.
L.; Nguyen, S. T.; Grubbs, R. H. J . Am. Chem. Soc. 1997, 119, 3887-
3897.
S0022-3263(97)02279-2 CCC: $15.00 © 1998 American Chemical Society
Published on Web 06/05/1998

4292 J . Org. Chem., Vol. 63, No. 13, 1998
Zuercher et al.
Sch em e 2a
The synthesis of dienetriyne 14 (Scheme 3) began with
silylation of 4-pentyn-1-ol with TBSCl. Deprotonation of
O-silyl derivative 9 and BF3‚OEt3-promoted ring-opening
of oxetane afforded the monoprotected acetylenic diol 10.
Oxidation and Wittig olefination of the resultant alde-
hyde produced O-silyl enyne 11. Desilylation and oxida-
tion with J ones reagent produced the carboxylic acid 12.
Conversion of 12 to the Weinreb amide 13 was ac-
complished via the acid chloride. Sequential addition of
3-butenylmagnesium bromide and the lithium monoan-
ion of 1,5-hexadiyne produced the tertiary alcohol, which
was protected with TBSOTf to afford dienetriyne 14.
Four N-protected polyamines (26-29) bearing one to
four cycloolefinic relay linkages, respectively, were pre-
pared to study the possibility of a cascade ring-opening/
ring-closing metathesis in such systems. The strategy
for the synthesis of 26-29 (Scheme 4) was comprised by
four reactions: (a) palladium-catalyzed ring opening6 of
cyclopentadiene monoepoxide; (b) treatment of the result-
ing amino alcohol with methyl chloroformate to form an
amino carbonate; and (c) or (d) palladium-catalyzed
amination6,15 reactions with either sodium p-toluene-
sulfonamide or N-allyl-p-toluenesulfonamide. Steps a-c
were repeated one to four times, respectively, and
terminated with step d, which yielded the desired pro-
tected polyamines 26-29. The N-protected polyamine
37 was prepared by the above-outlined procedure to study
the effect of olefin substitution on the yield of the
metathesis reaction. Because palladium-catalyzed ring-
opening of cyclopentadiene monoxide is stereoselective
and yields only the syn isomer, the total number of
stereoisomers in 26-29 and 37 was equal to the number
of relay linkages n.
To explore the possibility of utilizing cyclohexenes as
relays for polyamines in ring-opening/ring-closing me-
tathesis reactions, 30 was prepared by palladium-
catalyzed 1,4-diacetoxylation16 of 1,3-cyclohexadiene fol-
lowed by palladium-catalyzed amination of the resulting
diacetate.
P olycycliza tion Rea ction s. Treatment of the acyclic
precursors containing acetylenic relay units with a
catalytic amount of 1 at ambient or slightly elevated
temperatures results in the formation of fused and
nonfused carbo- and heterocyclic products in moderate
to good yields (Table 1).17 The products contain conju-
gated triene and tetraene systems.
a
Key: (a) NaH allyl or crotyl bromide, DMF, 70%; (b) TsCl,
NEt3, DMAP, CH2Cl2; (c) NaH, DMF, 3a , 60-82%; (d) (i) TMSC-
CH, BuLi, THF, (ii) K2CO3, MeOH, 86%; (e) allyl-NHTs, Pd2dba3‚
CHCl3, dppe, BSA, THF, %; (f) 3-butenylMgBr, THF, 89%; (g)
Ph3PCH2Br, t-BuOK, THF, 70%; (h) (i) BuLi, THF then 14, (ii)
Et3SiOTf, NEt3, CH2Cl2, two steps, 60%.
polycyclizations (Scheme 2). The linear precursor 4 was
prepared by alkylation of the anion of 2-butyne-1,4-diol
monoallyl ether 2a with propargyl chloride 3a .11 For the
preparation of 5, lithium (trimethylsilyl)acetylide was
added to trans-4-decenal; after desilylation, O-alkylation
with 3a produced 5. Palladium-catalyzed ring opening6
of cyclopentadiene monoepoxide with N-allyl-p-toluene-
sulfonamide and O-alkylation of the resulting amino
alcohol with propargyl chlorides 3a and 3b produced 6a
and 6b, respectively. The branched precursor 8 was
formed via sequential addition of 3-butenylmagnesium
bromide and the lithium anion of 7 to the Weinreb
amide12 of 4-pentynoic acid13 followed by silylation with
TESOTf. Enyne 7 was prepared via Corey-Fuchs reac-
tion of cis-4-decenal.14
In general, fused polycyclics are formed in higher yield
than nonfused ring systems (i.e., 17 and 18 vs 15). In
the intermediate case where the product contains both
types of ring linkages, 16, yields are also high. However,
it is not known whether this originates from the ther-
modynamic stability of product due to increased conjuga-
tion (17 and 18 are conformationally rigid while 15 is
not), a kinetic factor of conformational origin, or some
other effect.
The mechanism of the polycyclizations involves the
initial formation of a ruthenium alkylidene that under-
(14) (a) Matsumoto, M.; Kuroda, K. Tetrahedron Lett. 1980, 21,
4021-4024. (b) Corey, E. J .; Fuchs, P. L. Tetrahedron Lett. 1972, 13,
3679.
(15) Ba¨ckvall, J .-E.; Bystro¨m, S. E.; Aslanian, R. Tetrahedron Lett.
1985, 26, 1749-1752.
(16) Ba¨ckvall, J .-E.; Bystro¨m, S. E.; Nordberg, R. E. J . Org. Chem.
1984, 49, 4619.
(11) Propargyl chloride 3, rather than the tosylate, was isolated from
the reaction of 2 with tosyl chloride.
(12) Nahm, S.; Weinreb, S. M. Tetrahedron Lett. 1981, 22, 3815-
(17) Compounds 4 and 5 have been protected as trialkylsilyl ethers.
Cyclization proceeds without this protection, but the reaction rate is
slowed dramatically, possibly due to intramolecular chelation.
3818.
(13) Trost, B. M.; Shi, Y. J . Am. Chem. Soc. 1993, 115, 9421-9438.

Ruthenium-Catalyzed Polycyclization Reactions
J . Org. Chem., Vol. 63, No. 13, 1998 4293
Sch em e 3a
a
Key: (a) TBDMSCl, Net3, CH2Cl2, 98%; (b) BuLi, THF then oxetane, BF3‚OEt2, 84%; (c) PDC, CH2Cl2; (d) BuLi, Ph3PEtBr, THF, 64%
from 10; (e) CrO3, H2SO4, i-PrOH, 83%; (f) (COCl)2, CH2Cl2 then H2NMe(OMe)Cl, NEt3, 72%; (g) 3-butenylMgBr, THF, 86%; (h) 1,5-
hexadiyne, 1.0 equiv of BuLi, THF, 48%; (i) TBDMSOTf, NEt3, CH2Cl2, 96%.
goes a series of intramolecular metatheses with the relay
units prior to termination by a final ring closure. For
example, the conversion of 8 to 17 (Scheme 5) presumably
begins with metathesis of 1 with the monosubstituted
olefin of 8.18 The newly formed carbene subsequently
undergoes two intramolecular carbene-acetylene met-
atheses19 involving the respective metallacyclobutene
intermediates. The cyclization is completed by intramo-
lecular metathesis of the vinylcarbene with the disub-
stituted olefin to yield product 17 and propagating
alkylidene 20.
are consistent with the reported reactivity of 1 with
R-olefins.10a
Despite initial observation of low yields and competing
side reactions, cycloolefins as well as acetylenes are
effective relays in these polycyclization reactions. When
precursor 6a is exposed to 4 mol % 1, tricycle 19 is
recovered in only 40% yield. The mass balance is found
in an uncharacterized side product that appears to be
oligomerized starting material. This type of side reaction
The initiation and subsequent reactions of 1 are
1
followed by observing the H NMR signal of the R-proton
of the ruthenium alkylidene. As the benzylidene (singlet
20.02 ppm in CD2Cl2) is consumed, a signal for the
propagating alkylidene 20 appears. In the reactions of
5, 8, and 14, this species is expected to be ethylidene or
n-pentylidene and is observed initially as a multiplet
(ethylidene: quartet at 19.26 ppm in CD2Cl2; n-pentyl-
idene: triplet at 19.24 ppm). However, as the reaction
progresses, a singlet corresponding to the ruthenium
methylidene 21 (18.94 ppm in CD2Cl2) grows as the
alkylidene signal decays. Additionally, the formation of
ethylene (singlet, 5.35 ppm in CD2Cl2) and either 2-butene
or 5-decene is observed in the reaction mixture. These
observations indicate a secondary metathesis with the
R-olefin byproduct of the cyclization reaction (eq 6) and
Sch em e 4a
(18) The extra substituent on the disubstituted olefin is employed
to increase the relative rate of metathesis at the monosubstituted
“productive” olefin. When the reaction is conducted with an acyclic
precursor containing two monosubstituted olefins, product formation
is observed at a slower rate and to a lesser extent.
(19) A related process involving carbene-acetylene metathesis,
enyne metathesis ring-closure, has been reported utilizing tungsten
and ruthenium carbene complexes. (a) Katz, T. J .; Sivavec, T. M. J .
Am. Chem. Soc. 1985, 107, 737. (b) Kinoshita, A.; Mori, M. Synlett
1994, 1020. (c) Kinoshita, A.; Mori, M. J . Org. Chem. 1996, 61, 8356.
Similarly, carbene-acetylene metathesis allows for the recently
reported rearrangement-cyclization of triynes to produce aromatics,
an example of which is shown. (d) Peters, J . U.; Blechert, S. Chem.
Commun. 1997, 1983.
a
Key: (a) Pd2dba3‚CHCl3, dppe, BSA, THF, 40-100%; (b)
CH3OCOCl, C5H5N, CH2Cl2, 80-100%; (c) Ts-NHNa, Pd(PPH3)4,
dppe, THF, 60-80%; (d) allyl-NHTs, Pd2dba3‚CHCl3, PPh3, BSA,
THF, 40-88% or allyl-NTsNa, Pd(PPH3)4, dppe, THF, 72%.

4294 J . Org. Chem., Vol. 63, No. 13, 1998
Zuercher et al.
Sch em e 5
Ta ble 1. Resu lts of Rin g-Op en in g-Rin g-Closin g
has been observed previously in cycloolefins metathesis
relay reactions, and the problem was ameliorated through
alkyl substitution of one of the acyclic olefins of 6a ,
thereby slowing the relative rate of the competing side
reaction.7c This strategy works in the present study as
well: when 6b is exposed to 4 mol % 1, cyclization
proceeds cleanly to a single product, and the tricycle 19
is isolated in 76% yield.
Meta th esis Rea ction s
Multiple cycloolefinic relays can be used to promote
cascades of ring-opening/ring-closing metathesis reac-
tions. Treatment of N-protected polyamines 26-29,
bearing one to four cycloolefinic relays, respectively, with
catalytic amounts of 1 at ambient or slightly elevated
temperatures results in the formation of N-protected
polycyclic amines 31-34 in moderate to good yields (eq
7; Table 2). Similarly, N-protected polyamine 37, bearing
one terminal and one methyl-substituted olefin, is con-
verted to N-protected polycyclic amine 31 in good yield.20
The mechanism of these polycyclizations is thought to
be similar to the previously described mechanism for the
(20) Although olefin substitution results only in a 4% increase in
yield of 31 (Table 2, entries 1 and 2), the workup is greatly simplified
due to the absence of difficult to separate impurities.

Ruthenium-Catalyzed Polycyclization Reactions
J . Org. Chem., Vol. 63, No. 13, 1998 4295
Sch em e 6
polycyclization of polyenes bearing acetylenic relays
(Scheme 5) and involves an initial formation of a ruthe-
nium alkylidene that undergoes a series of intramolecu-
lar metatheses with the cyclopentene relay units prior
to termination by a final ring closure. For example, the
conversion of 27 to 32 (Scheme 6) presumably begins with
metathesis of 1 with the monosubstituted olefin of 27.
The newly formed carbene subsequently undergoes two
intramolecular ring-opening/ring-closing metathesis reac-
tions, involving the respective metallacyclobutene inter-
mediates. The cyclization is completed by metathesis of
the ruthenium carbene with the monosubstituted olefin
to yield product 32 and a propagating methylidene.
The polycyclization reactions of polyamines containing
one to two cyclopentene metathesis relays proceed in good
yields (Table 2). However, an increasing number of
cyclopentene relays allows for a greater variety of inter-
molecular side reactions and the yields drop off sharply
under the same conditions (Table 2, entry 3). This
problem is effectively solved by decreasing reaction
concentration and temperature (Table 2, entry 4); this
decreases the relative rate of intermolecular side reac-
tions with respect to intramolecular metathesis cycliza-
tions and lowers the rate of catalyst decomposition.
Ruthenium alkylidenes with salen ligands such as 35
have exhibited greater stability than 1 in the RCM of
diallyl malonates.21 Although the cyclizations catalyzed
by 35 are generally slower, increased yields of an ad-
ditional 8-10% for the more challenging substrates
(Table 2, entries 5 and 7) are observed.
N-protected polyamines. At 45 °C, 30 is converted to 36
in 66% yield in a 0.05 M benzene solution.
It is anticipated that treatment of acyclic N-protected
polyamines bearing multiple cyclohexene relays with
olefin metathesis catalysts will lead to polycyclic N-
protected amines.
Ta ble 2. Resu lts of Ru th en iu m -Ca ta lyzed
P olycycliza tion s of Acyclic P olya m in es (Eq 7) u p on
Tr ea tm en t w ith 5 m ol % Ca ta lyst
time
(h) solvent
concn
(M)
T
yield
entry precursor catalyst
(°C) (%)
1
2
3
4
5
6
7
8
26
37
27
28
28
28
29
29
1
1
1
1
1
35
1
35
1
4
3
8
8
24
48
48
C6H6
C6H6
C6H6
C6H6
0.05
0.05
0.05
0.06
rt
rt
45
45
76
80
70
20
50
60
51
59
CH2Cl2 0.003 rt
CH2Cl2 0.003 40
CH2Cl2 0.003 rt
CH2Cl2 0.003 40
Con clu sion s
We have presented an efficient, catalytic method for
the production of polycyclic molecules from acyclic pre-
cursors. The reaction proceeds through a cascade of
metathesis steps with either acetylenic or cycloalkenyl
relay units. A variety of structural types are accessible
depending on the topology of the precursor and relay unit
employed. The use of more and varied metathesis relays
as well as the further functionalization of the resulting
cyclolefin systems are currently under investigation.
Exp er im en ta l Section
Gen er a l Meth od s. High-resolution mass spectra were
provided by the Southern California Mass Spectrometry Facil-
ity (University of California at Riverside). Analytical thin-
In addition to cyclopentenes, cyclohexenes are also
effective as metathesis relays in the polycyclizations of
(21) Chang, S.; J ones, L., II; Wang, C.; Henling, L. M.; Grubbs, R.
H.; Organometallics 1997, submitted for publication.

4296 J . Org. Chem., Vol. 63, No. 13, 1998
Zuercher et al.
layer chromatography (TLC) was performed using silica gel
60 F254 precoated plates (0.25 mm thickness) with a fluores-
cent indicator. Visualization was accomplished with one or
more of the following: UV light, KMnO4, phosphomolybdic acid
(PMA), cerric ammonium nitrate (CAN), or p-anisaldehyde
solution followed by heating. Flash chromatography was
performed using silica gel 60 (230-400 mesh) from EM
Science.22
IR (neat, cm-1) 3313, 3078, 3007, 2956, 2875, 2236, 2121, 1642,
1090; HRMS calcd for C26H45OSi (MH+) 401.3240, found
401.3247.
Com p ou n d 14: 1H NMR (CDCl3, 300 MHz) δ 5.89-5.76
(m, 1H), 5.55-5.40 (m, 2H), 5.01 (dd, J ) 17.2, 1.8 Hz, 1H),
4.93 (dd, J ) 10.0, 1.8 Hz, 1H), 2.45-2.14 (m, 12H), 2.01 (t, J
) 2.4 Hz, 1H), 1.84-1.77 (m, 3H), 1.69-1.61 (m, 4H), 0.85 (s,
9H), 0.14 (s, 6H); 13C NMR (CDCl3, 75 MHz) δ 138.7, 129.8,
129.0, 125.9, 125.0, 114.2, 83.9, 83.8, 82.6, 80.3, 79.5, 71.4, 69.4,
42.4, 42.2, 32.3, 28.8, 26.7, 25.8, 19.0, 18.8, 18.6, 18.2, 14.2,
12.8, -2.9; IR (neat, cm-1) 3311, 3078, 3015, 2928, 2856, 2236,
2122, 1641, 1254, 1090; HRMS calcd for C26H40OSi (MH+)
397.2927, found 397.2912.
3,4-Bis(2,5-d ih yd r ofu r a n -3-yl)-2,5-d ih yd r ofu r a n (15):
1H NMR (CD2Cl2, 300 MHz) δ 5.78 (s, 2H), 4.74 (s, 4H), 4.65
(s, 8H); 13C NMR (CD2Cl2, 100 MHz) δ 132.2 (s), 128.1 (s), 125.9
(d, J ) 179 Hz), 78.2 (t, J ) 147 Hz), 75.6 (t, J ) 147 Hz), 75.5
(t, J ) 147 Hz); IR (neat, cm-1) 3076, 2846, 1078, 1064; HRMS
calcd for C12H14O3 (M+) 206.0943, found 206.0937.
All reactions were carried out under an inert atmosphere
in oven-dried glassware unless otherwise specified. Catalyst
1 was prepared according to published procedure and is
commercially available.10a Catalyst 35 was prepared according
to the published procedure and was generously provided by
Dr. Sukbok Chang.21 Solvents were purified by passage
through
a column containing A-5 alumina (all solvents)
followed by a column containing Q-5 reactant (nonethereal
solvents). Argon was purified by passage through columns of
BASF R3-11 catalyst (Chemalog) and 4 Å molecular sieves
(Linde). Allyl bromide was purchased from ARCOS. All other
reagents were purchased from the Aldrich Chemical Co.
Cyclopentadiene monoepoxide was prepared following the
published procedure.23
3-(2,5-Dih yd r ofu r a n -3-yl)-1,6,7,8-t et r a h yd r ob en zofu -
r a n (16). To a stirring solution of 5 (305 mg, 1.1 mmol) in
benzene (20 mL, 0.05 M) was added 1 (36 mg, 44 µmol, 0.04
equiv). The reaction was stirred at 45 °C until complete
consumption of the starting material was observed by TLC
(product Rf ) 0.2; 10% EtOAc in hexanes), about 4 h. The
solvent was removed under reduced pressure, and the remain-
ing colored oil was purified by flash chromatography (10%
EtOAc in hexanes) to yield the product 17 as a clear, light
yellow oil (158 mg, 79%): 1H NMR (CDCl3, 300 MHz) δ 6.18
(dt, J ) 9.9, 2.0 Hz, 1H), 6.00-5.90 (m, 1H), 5.64 (t, J ) 2.0
Hz), 4.68-4.28 (m, 2H), 4.78-4.67 (m, 5H), 2.32-2.18 (m, 3H),
1.70-1.59 (m, 1H); 13C NMR (CDCl3, 100 MHz) δ 134.2, 133.6,
132.5, 123.0, 121.0, 120.2, 84.3, 75.3, 75.2, 75.1, 29.9, 25.1; IR
(neat, cm-1) 3033, 2942, 2840, 1099, 1086; HRMS calcd for
4,9,16-Tr ioxa -1,16-h ep ta d eca d ien e-6,11-d iyn e (4): 1H
NMR (C6D6, 300 MHz) δ 5.74-5.63 (m, 1H), 5.18-5.10 (m, 1H),
4.96-4.91 (m, 1H), 4.04 (t, J ) 1.8 Hz, 2H), 3.86 (t, J ) 1.8
Hz, 2H), 3.81-3.78 (m, 2H); 13C NMR (C6D6, 100 MHz) δ 134.7,
116.8, 83.1, 81.6, 70.0, 56.8, 56.1; IR (neat, cm-1) 3080, 3015,
+
2982, 2943, 2854, 1074; HRMS calcd for C14H18O3 (MNH4
252.1600, found 252.1599.
)
(E)-10-Eth yn yl-4,9-d ioxa -1,13-n on a d eca d ien -6-yn e (5):
1H NMR (C6D6, 300 MHz) δ 5.96-5.83 (m, 1H), 5.48-5.19 (m,
4H), 4.31 (m, 3H), 4.19 (t, J ) 1.2 Hz, 2H), 4.05 (dt, J ) 5.8,
1.3 Hz, 2H) 2.45 (d, J ) 2.1 Hz, 1H), 2.15 (q, J ) 7.2 Hz, 2H),
1.96 (q, J ) 6.6 Hz, 2H), 1.84 (m, 2H), 1.35-1.23 (m, 6H), 0.87
(t, J ) 6.8 Hz, 3H); 13C NMR (CDCl3, 100 MHz) δ 133.9, 131.6,
128.5, 117.9, 82.3, 82.0, 81.9, 74.4, 70.6, 67.4, 57.4, 56.0, 35.2,
32.5, 31.3, 29.2, 28.1, 22.5, 14.1; IR (neat, cm-1) 3304, 3080,
3017, 2954, 2925, 2854, 2112, 1071; HRMS calcd for C19H27O2
([M - H]+) 287.2011, found 287.1999.
C
12H14O2 (M+) 190.0994, found 190.0985.
10-[(Tr ieth ylsilyl)oxy]tr icyclo[8.3.0.01,10]tr id eca -1(13),-
2(7),5-tr ien e (17). To a stirring solution of 1 (9.9 mg, 12 µmol,
0.04 equiv) in benzene (10 mL, 0.05 M) was added 8 (199 mg,
0.50 mmol). The reaction was stirred at 45 °C until complete
consumption of starting material was observed by TLC (prod-
uct Rf ) 0.3; 2% Et2O in hexanes), about 4 h. The solvent
was removed under reduced pressure, and the remaining dark
oil was purified by flash chromatography (2% Et2O in hexanes)
to yield the product 17 as a clear, light yellow oil (126 mg,
84%): 1H NMR (CDCl3, 300 MHz) δ 5.84-5.82 (m, 2H), 5.60
(s, 1H), 2.68-2.51 (m, 4H), 2.39-1.78 (m, 6H), 1.57-1.45 (m,
2H), 0.88 (t, J ) 7.9 Hz, 9H), 0.49 (q, J ) 7.9, 6H); 13C NMR
(CDCl3, 100 MHz) δ 145.10, 130.32, 128.54, 126.45, 123.58,
123.48, 82.94, 39.44, 37.05, 30.33, 27.03, 23.10, 22.99, 7.18,
6.06; IR (neat, cm-1) 3028, 2953, 2875, 1622, 1080; HRMS calcd
for C19H30OSi (M+) 302.2066, found 302.2051.
Com p ou n d 6a : 1H NMR (CDCl3, 300 MHz) δ 7.70 (d, J )
8.4 Hz, 2H), 7.28 (d, J ) 8.4 Hz, 2H), 5.99-5.76 (m, 3H), 5.62-
5.59 (m, 1H), 5.32-5.07 (m, 4H), 4.97-4.93 (m, 1H), 4.46-
4.42 (m, 1H), 4.15-4.12 (m, 4H), 4.03-4.00 (m, 2H), 3.72-
3.54 (m, 2H), 2.43 (dt, J ) 14.7, 8.0 Hz, 1H), 2.41 (s, 3H), 1.38
(dt, J ) 14.4, 4.6 Hz, 1H); 13C NMR (CDCl3, 100 MHz) δ 143.2,
137.3, 135.9, 134.3, 134.2, 133.8, 129.6, 127.2, 117, 9, 116.9,
82.2, 80.9, 70.6, 61.7, 57.3, 56.6, 45.6, 34.9, 21.5; IR (neat, cm-1
)
3078, 3020, 2980, 2922, 2854, 1645, 1088; HRMS calcd for
C
22H31N2O4S (MNH4+) 419.2004, found 419.2004.
Com p ou n d 6b tr a n s isom er (m a jor ): 1H NMR (CDCl3,
400 MHz) δ 7.70 (d, J ) 8.0 Hz, 2H), 7.28 (d, J ) 8.0 Hz, 2H),
5.97 (dt, J ) 5.5, 2.2 Hz, 1H), 5.87-5.50 (m, 3H), 5.22-5.07
(m, 4H), 4.96-4.93 (m, 1H), 4.46-4.43 (m, 1H), 4.16-4.07 (m,
4H), 3.95-3.93 (m, 2H), 3.73-3.56 (m, 2H), 2.40 (s, 3H), 1.71-
1.64 (m, 3H), 1.42-1.36 (dt, J ) 14.3, 4.8 Hz, 1H); 13C NMR
(CDCl3, 100 MHz) δ 143.3, 137.6, 136.1, 134.5, 134.3, 130.7,
129.7, 127.3, 126.8, 117.1, 82.2, 81.0, 70.5, 65.0, 61.9, 57.1, 56.7,
45.7, 35.2, 21.6, 17.8; IR (neat, cm-1) 2939, 2854, 2359, 1340,
1160, 1091; HRMS calcd for C23H30NO4S (MH+) 416.1912,
found 416.1905.
Com p ou n d (18): To a stirring solution of 14 (42 mg, 0.1
mmol) in C6H6 (2 mL, 0.05 M) was added 1 (3.5 mg, 4 µmol,
0.04 equiv). After the mixture was stirred for 4 h at room
temperature, 14 was not detectable by TLC (product Rf ) 0.5;
1% NEt3 in hexanes), and the reaction mixture was purified
by flash chromatography (1% NEt3 in hexanes elution). The
product 18 was isolated as a viscous, light yellow oil: 26 mg,
1
70%; H NMR (CDCl3, 300 MHz) δ 5.95-5.91 (m, 1H), 5.75-
5.69 (m, 1H), 5.46 (s, 1H), 2.64-2.53 (m, 2H), 2.40-2.34 (m,
2H), 2.21-2.02 (m, 4H), 1.82-1.71 (m, 1H), 1.52-1.42 (m, 1H),
0.99 (s, 9H), 0.09 (s, 3H), 0.00 (s, 3H); 13C NMR (C6D6, 100
MHz) δ 145.0, 132.6, 128.5, 125.3, 124.3, 124.0, 82.9, 46.8, 39.7,
37.1, 30.6, 27.7, 26.2, 25.9, 24.1, 23.8, 18.7, 14.2, 12.5, -2.7,
-3.1; IR (neat, cm-1) 3037, 2954, 2929, 2855, 1634, 1472, 1252,
1076.
(Z)-5-(3-Bu tyn yl)-5-[(tr ieth ylsilyl)oxy]-1,10-h exa d eca -
d ien -6-yn e (8): 1H NMR (C6D6, 300 MHz) δ 5.85-5.72 (m,
1H), 5.54-5.38 (m, 2H), 5.06 (dd, J ) 17.1, 1.6 Hz, 1H), 4.96
(dd, J ) 10.0, 0.7 Hz, 1H), 2.54-2.47 (m, 2H), 2.30-2.23 (m,
2H), 2.15-1.93 (m, 8H), 1.79-1.72 (m, 3H), 1.29-1.23 (m, 6H),
1.04 (t, J ) 7.9 Hz, 9H), 0.89 (t, J ) 6.9, 3H), 0.76 (q, J ) 7.9
Hz, 6H); 13C NMR (CDCl3, 75 MHz) δ 138.56, 131.43, 127.65,
114.27, 85.50, 84.85, 82.67, 71.15, 67.79, 42.01, 41.56, 31.50,
29.31, 28.80, 27.28, 26.40, 22.56, 19.14, 14.08, 13.90, 7.09, 6.11;
Com p ou n d 19: 1H NMR (CD2Cl2, 300 MHz) δ 7.66 (d, J )
8.4 Hz, 2H), 7.32 (d, J ) 8.4 Hz, 2H), 5.73-5.57 (m, 4H), 5.03-
4.93 (m, 1H), 4.82-4.67 (m, 6H), 4.52-4.46 (m, 1H), 4.16-
4.01 (m, 2H), 2.41 (s, 3H), 2.21-2.13 (m, 1H), 2.00-1.90 (m,
1H); 13C NMR (CDCl3, 100 MHz) δ 143.7, 132.2, 132.0, 130.1,
129.8, 127.4, 126.4, 124.2, 123.4, 84.0, 76.2, 75.0, 74.5, 64.7,
55.5, 42.3, 21.2; IR (neat, cm-1) 2847, 1597, 1470, 1162, 1088;
HRMS calcd for C20H24NO4S (MH+) 374.1426, found 374.1423.
(22) Still, W. C.; Kahn, M.; Mitra, A. J . Org. Chem. 1978, 43, 2923.
(23) Korach, M.; Nielsen, D. R.; Rideout, W. H. J . Am. Chem. Soc.
1960, 82, 4328.

Ruthenium-Catalyzed Polycyclization Reactions
J . Org. Chem., Vol. 63, No. 13, 1998 4297
Gen er a l P r oced u r e for th e F or m a tion of Am in ocyclo-
p en ten yl Alcoh ols (Sch em e 4a ). To a stirring solution of
palladium dibenzylidene acetone adduct (21 mg, 0.02 mmol,
0.02 equiv) in THF (1 mL, 0.02 M) was added (diphenylphos-
phino)ethane (32 mg, 0.08 mmol, 0.08 equiv). The resulting
deep violet mixture was stirred for several minutes at room
temperature until its color changed to yellow. To this reaction
mixture was added 22 (447 mg, 1.0 mmol, 1 equiv) in THF (1
mL, 1 M). The resulting mixture was cooled to 0 °C and
treated with N,O-bis(trimethylsilyl)acetamide (305 mg, 1.5
mmol, 1.5 equiv). The reaction mixture was allowed to stir
for 20 min, after which time cyclopentadiene monoxide (123
mg, 1.5 mmol, 1.5 equiv) was added dropwise over a period of
1 h. The temperature was kept at 0 °C for an additional hour,
after which it was allowed to warm to room temperature and
stirred overnight. The solvent was removed under reduced
pressure. The remaining, dark brown residue was redissolved
in Et2O (10 mL) and hydrolyzed with 4 N aqueous HCl (5 mL)
until complete disappearance of the initial reaction product,
TMS-protected alcohol, was observed by TLC (Rf ) 0.6, 30%
EtOAc in hexanes). The organic phase was separated, and
the aqueous phase was extracted twice with Et2O (10 mL).
The organic phases were combined and dried over MgSO4, and
the solvent was removed under reduced pressure. The free
alcohol 23 (400 mg, 76%) was isolated by flash chromatography
as a clear colorless oil.
ance of the product. The reaction mixture was diluted with
H2O (10 mL) and benzene (10 mL), cooled to 0 °C, and carefully
made basic with KOH. The liquid phases were separated, and
the aqueous phase was extracted twice with CH2Cl2 (10 mL).
All organic phases were combined, dried over MgSO4, and
filtered, and the solvent was removed under reduced pressure.
The resulting oil was purified by flash chromatography (20%
EtOAc in hexanes) to yield 31 as a white solid (135 mg, 72%).
Typ ica l P r oced u r e for th e Meta th esis Rea ction of 37
(Eq 7). To a stirring solution of 37 (500 mg, 1.0 mmol) in C6H6
(20 mL, 0.05 M) was added 1 (41 mg, 0.05 mmol, 0.05 equiv).
The reaction mixture was stirred at rt for 4 h, at which time
complete consumption of the starting material was observed
by TLC. The reaction mixture was purified by flash chroma-
tography (20% EtOAc in hexanes) to yield 31 as a white solid
(365 mg, 80%).
Gen er a l P r oced u r e for th e Meta th esis Rea ction s of
27-29 (Eq 7). To a stirring solution of 29 (45 mg, 38 µmol)
in CH2Cl2 (12.5 mL, 0.003 M) was added 35 (1.7 mg, 1.89 µmol,
0.05 equiv). The reaction mixture was stirred at 40 °C for 24
h, at which time complete consumption of the starting material
was observed by TLC (product Rf ) 0.4; 40% EtOAc in
hexanes). The solvent was removed under reduced pressure.
The remaining residue was purified by flash chromatography
(20% EtOAc in hexanes) to yield 34 as a white solid (26 mg,
59%).
Gen er a l P r oced u r e for th e F or m a tion of Am in ocyclo-
p en ten yl Ca r bon a tes (Sch em e 4b). To a stirring solution
of 23 (11.0 g, 37.5 mmol) in CH2Cl2 (300 mL, 0.125 M) were
slowly added at 0 °C methyl chloroformate (17.8 g, 188 mmol,
5 equiv) and pyridine (5.93 g, 75 mmol, 2 equiv). The reaction
mixture was stirred at room temperature until complete
consumption of starting material was observed by TLC (prod-
uct Rf ) 0.4, 30% EtOAc in hexanes). The reaction mixture
was washed twice with water (100 mL), dried over MgSO4,
and filtered, and the solvent was removed under reduced
pressure. Flash chromatography afforded 24 as a yellow oil
(13.4 g, 100%).
Gen er a l P r oced u r e for th e F or m a tion of Am in ocyclo-
p en ten yl p-Tolu en esu lfon a m id es (Sch em e 4c). To a
stirring solution of 24 (8.5 g, 24.4 mmol, 1.0 equiv) in THF
(120 mL, 0.2M) were added sodium p-toluenesulfonamide (4.17
g, 24.4 mmol, 1 equiv), Pd(PPh3)4 (2.26 g, 1.95 mmol, 0.08
equiv), and (diphenylphosphino)ethane (777 mg, 1.95 mmol,
0.08 equiv). The resulting reaction mixture was stirred
overnight. The solvent was removed under reduced pressure,
and the remaining dark residue was purified by flash chro-
matography to afford 25, as a yellow solid (8.6 g, 79%).
Gen er a l P r oced u r e for th e F or m a tion of Am in ocyclo-
p en ten yl N-Allyl-p-tolu en esu lfon a m id es (Sch em e 4d ). To
a stirring solution of palladium dibenzylidene acetone adduct
(43 mg, 42 µmol, 0.08 equiv) in THF (2 mL, 0.02 M) was added
triphenylphosphine (27 mg, 104 µmol, 0.2 equiv). The result-
ing yellow-brown mixture was stirred at room temperature for
20 min. To this reaction mixture was added N-allyl-p-
toluenesulfonamide (115 mg, 546 µmol, 1.05 equiv). The
resulting mixture was cooled to 0 °C and treated with N,O-
bis(trimethylsilyl)acetamide (212 mg, 1.04 mmol, 2 equiv) for
20 min, after which time 24 (300 mg, 520 µmol, 1.0 equiv) in
THF (2.5 mL, 0.21 M) was added dropwise over a period of 1
h. The temperature was kept at 0 °C for an additional hour,
after which the reaction mixture was allowed to warm to room
temperature and stirred overnight. The solvent was removed
under reduced pressure. Compound 27 (300 mg, 80%) was
isolated by flash chromatography as a yellow solid.
Com p ou n d 26: 1H NMR (C6D6, 300 MHz) δ 7.65 (d, J )
8.2 Hz, 4H), 6.74 (d, J ) 8.2 Hz, 4H), 5.80-5.67 (m, 2H), 5.19
(s, 2H), 5.10 (dd, J ) 17.2, 1.4 Hz, 2H), 4.84 (dd, J ) 10.2, 1.4
Hz, 2H), 4.78 (app t, J ) 8.1 Hz, 2H), 3.56-3.52 (m, 4H), 2.19
(app dt, J ) 13.4, 8.1 Hz, 1H), 1.88 (s, 6H), 1.44 (app dt, J )
13.4, 8.1 Hz, 1H); 13C NMR (CDCl3, 100 MHz) δ 143.5, 137.6,
135.8, 133.9, 129.8, 127.2, 117.1, 61.6, 46.6, 34.4, 21.5; IR (neat,
cm-1) 2921, 1598, 1335, 1158, 1091; HRMS calcd for C25H31
N2O4S2 (MH+) 487.1725, found 487.1730.
-
Com p ou n d 27, tw o isom er s: 1H NMR (CDCl3, 300 MHz)
δ 7.71-7.55 (m, 6H), 7.33-7.22 (m, 6H), 5.92-5.74 (m, 2H),
5.63-5.44 (m, 4H), 5.24-5.03 (m, 4H), 4.87-4.74 (m, 2H),
4.38-4.22 (m, 2H), 3.90-3.66 (m, 4H), 2.41-2.31 (m, 11H),
1.88-1.73 (m, 2H); 13C NMR (CDCl3, 100 MHz) δ 143.5, 143.4,
138.9, 137.7, 136.2, 134.6, 134.1, 133.1, 132.7, 129.8, 129.8,
127.2, 127.2, 127.1, 117.0, 116.9, 61.9, 61.8, 60.9, 60.7, 46.6,
46.6, 36.5, 36.1, 21.5; IR (neat, cm-1) 3065, 2954, 1598, 1340,
1158, 1091; HRMS calcd for C37H43N3O6S3Na (MNa+) 744.2212,
found 744.2245.
Com p ou n d 28, th r ee isom er s: 1H NMR (CDCl3, 400
MHz) δ 7.67-7.56 (m, 8H), 7.36-7.18 (m, 8H), 5.89-5.74 (m,
2H), 5.72-5.60 (m, 2H), 5.58-5.48 (m, 2H), 5.45-5.38 (m, 2H),
5.23-5.00 (m, 4H) 4.88-4.76 (m, 2H), 4.47-4.31 (m, 4H),
3.89-3.71 (m, 4H), 2.55-2.34 (m, 15H), 2.00-1.83 (m, 3H);
IR (neat, cm-1) 2923, 1597, 1331, 1155, 1085; HRMS calcd for
C
49H56N4O8S4Na (MNa+) 979.2879, found 979.2915.
Com p ou n d 29, fou r isom er s: 1H NMR (CDCl3, 400 MHz)
δ 7.68-7.58 (m, 10H), 7.31-7.23 (m, 10H), 5.92-5.53 (m, 8H),
5.45-5.40 (m, 2H), 5.25-5.04 (m, 4H), 4.88-4.78 (m, 2H),
4.51-4.37 (m, 6H), 3.90-3.72 (m, 4H), 2.58-2.43 (m, 19H),
2.12-1.84 (m, 4H); IR (neat, cm-1) 3063, 2955, 1598, 1332,
1157, 1092; LRMS calcd for C61H70N5O10S5 (MH+) 1192, found
1192.
Com p ou n d 30: 1H NMR (CDCl3, 300 MHz) δ 7.66 (d, J )
8.1 Hz, 4H), 7.26 (d, J ) 8.1, 4H), 5.85-5.72 (m, 2H), 5.35 (s,
2H), 5.20-5.06 (m, 4H), 4.29 (s, 2H), 3.90-3.83 (dd, J ) 16.9,
5.4 Hz, 2H), 3.69-3.61 (dd, J ) 16.9, 5.8 Hz, 2H), 2.40 (s, 6H),
1.73-1.71 (m, 4H); 13C NMR (CDCl3, 100 MHz) δ 143.3, 138.1,
136.0, 131.9, 129.8, 127.1, 116.9, 52.3, 47.5, 25.8, 21.5; IR (neat,
cm-1) 3028, 2923, 1598, 1337, 1163, 1090; HRMS calcd for
Typ ica l P r oced u r e for th e Meta th esis Rea ction of 26
(Eq 7). To a stirring solution of 26 (200 mg, 0.41 mol) in
benzene (8 mL, 0.05M) was added 1 (17 mg, 21 µm, 0.05 equiv).
The reaction mixture was stirred at 45 °C for 1 h, at which
time complete consumption of the starting material was
observed by TLC (product Rf ) 0.3; 30% EtOAc in hexanes).
The solvent was removed under reduced pressure. The
remaining dark oil was redissolved in 1 mL of benzene and
treated with concentrated H2SO4 (1 mL) and 0.1 mL of H2O
(0.1 mL) until TLC of the organic phase indicates disappear-
C
26H33N2O4S2 (MH+) 501.1882, found 501.1889.
Com p ou n d 31: 1H NMR (CDCl3, 300 MHz) δ 7.70 (d, J )
8.3 Hz, 4H), 7.31 (d, J ) 8.3 Hz, 4H), 5.86-5.81 (m, 2H), 5.64-
5.61 (m, 2H), 4.61-4.54 (m, 2H), 4.19-4.04 (m, 4H), 2.47-
2.40 (m, 7H), 2.17-2.07 (m, 1H); 13C NMR (CDCl3, 100 MHz)
δ 143.6, 134.3, 130.5, 129.8, 127.6, 24.6, 64.7, 55.4, 42.6, 21.5;
IR (neat, cm-1) 3066, 2918, 2861, 1596, 1340, 1163, 1095;
HRMS calcd for C23H27N2O4S2 (MH+) 459.1412, found 459.1404.

4298 J . Org. Chem., Vol. 63, No. 13, 1998
Zuercher et al.
Com p ou n d 32, tw o isom er s: 1H NMR (CDCl3, 400 MHz)
δ 7.70-7.65 (m, 6H), 7.29-7.27 (m, 6H), 6.09 (s, 2H), 5.62-
5.56 (m, 4H), 4.72 (d, J ) 8.8 Hz, 2H), 4.56-4.48 (m, 2H),
4.14-4.02 (m, 4H), 2.69-2.64 (m, 2H), 2.40-2.37 (m, 9H),
1.95-1.88 (m, 2H); 13C NMR (CDCl3, 100 MHz) δ 143.7, 142.9,
139.4, 134.4, 130.5, 129.8, 129.7, 129.6, 127.6, 126.8, 125.0,
65.0, 64.7, 55.4, 40.1, 21.6, 21.5; IR (neat, cm-1) 2923, 1597,
125.0, 67.1, 56.0, 30.0, 21.5; IR (neat, cm-1) 2911, 2859, 1592,
1330, 1157, 1089, 1047; HRMS calcd for C24H29N2O4S2 (MH+)
473.1569, found 473.1570.
Com p ou n d 37, tr a n s isom er (m a jor ): 1H NMR (C6D6,
300 MHz) δ 7.62 (app t, J ) 6.6 Hz, 4H), 7.26 (d, J ) 6.6 Hz,
2H), 7.24 (d, J ) 6.6 Hz, 2H), 5.78-5.71 (m, 1H), 5.52-5.28
(m, 4H), 5.14-5.04 (m, 2H), 4.76-4.72 (m, 1H), 3.70-3.51 (m,
4H), 2.39 (s, 3H), 2.38 (s, 3H), 2.29 (dt, J ) 10.0, 6.2 Hz, 1H),
1340, 1161, 1093; HRMS calcd for
694.2079, found 694.2068.
C
35H40N3O6S3 (MH+)
1.57 (dd, J ) 4.9, 1.1 Hz, 3H), 1.46 (dt, J ) 10.0, 6.2, 1H); 13
C
Com p ou n d 33, th r ee isom er s: 1H NMR (CDCl3, 400
MHz) δ 7.73-7.64 (m, 8H), 7.30-7.26 (m, 8H), 6.15-6.03 (m,
2H), 5.84-5.71 (m, 2H), 5.62-5.57 (m, 4H), 4.82-4.37 (m, 6H),
4.17-4.04 (m, 4H), 2.95-2.91, 2.72-2.54 (m, 3H), 2.44-2.28
(m, 12H), 2.11-1.85 (m, 3H); IR (neat, cm-1) 3066, 2923, 2869,
1598, 1339, 1162, 1099; HRMS calcd for C47H53N4O8S4 (MH+)
929.2746, found 929.2747.
NMR (CDCl3, 100 MHz) δ 143.5, 143.3, 137.8, 137.5, 135.8,
134.2, 133.5, 129.8, 129.7, 128.5, 128.4, 127.2, 127.1, 117.1,
61.5, 61.5, 46.5,46.4, 34.5, 21.6, 21.5, 17.6; IR (neat, cm-1) 2922,
1594, 1440, 1379, 1331, 1156, 1085; HRMS calcd for C26H36
-
N3O4S2 (MNH4+) 518.7145, found 518.7145.
Ack n ow led gm en t. The authors wish to thank Dr.
Soong-Hoon Kim for helpful discussions. This work was
supported by the National Institutes of Health.
Su p p or tin g In for m a tion Ava ila ble: 1H NMR of all new
compounds prepared in this study (20 pages). This material
is contained in libraries on microfiche, immediately follows this
article in the microfilm version of the journal, and can be
ordered from the ACS; see any current masthead page for
ordering information.
Com p ou n d 34, fou r isom er s: 1H NMR (CDCl3, 400 MHz)
δ 7.77-7.62 (m, 10H), 7.34-7.26 (m, 10H), 6.18-6.12 (m, 2H),
5.92-5.55 (m, 8H), 4.85-4.36 (m, 8H), 4.17-4.03 (m, 4H),
2.96-2.92, 2.71-2.51, 2.40-2.63 (m, 19H), 2.12-1.81 (m, 4H);
IR (neat, cm-1) 2922, 1598, 1338, 1162, 1092; HRMS calcd for
C
59H66N5O10S5 (MH+) 1164.3413, found 1164.3467.
Com p ou n d 36: 1H NMR (CDCl3, 400 MHz) δ 7.69 (d, J )
8.3 Hz, 4H), 7.29 (d, J ) 8.3, 4H), 5.63-5.54 (m, 4H), 4.54 (s,
2H), 4.18-4.03 (m, 4H), 2.40 (s, 6H), 1.83-1.82 (m, 4H); 13C
NMR (CDCl3, 100 MHz) δ 143.4, 134.7, 129.8, 129.7, 127.5,
J O972279G