Cyclopentannulation by an iterative process of sequential Claisen rearrangement and enyne radical closure: Routes to triquinane and propellane systems and use in the synthesis of (±)-ceratopicanol

Article abstract of DOI:10.1021/jo951930h

Cycloalkenyl acetylenes 4, which are easily prepared from allylic alcohols by Claisen rearrangement and homologation (1 → 4), generally undergo radical cyclization (4 → 6) on treatment with stannyl radicals. The products (6) can themselves be converted in

Full text of DOI:10.1021/jo951930h

J . Org. Chem. 1996, 61, 2095-2108
2095
Cyclop en ta n n u la tion by a n Iter a tive P r ocess of Sequ en tia l Cla isen
Rea r r a n gem en t a n d En yn e Ra d ica l Closu r e: Rou tes to Tr iqu in a n e
a n d P r op ella n e System s a n d Use in th e Syn th esis of
(()-Cer a top ica n ol
D. L. J . Clive,* Steven R. Magnuson, Hartford W. Manning, and Darrin L. Mayhew
Chemistry Department, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
Received October 31, 1995X
Cycloalkenyl acetylenes 4, which are easily prepared from allylic alcohols by Claisen rearrangement
and homologation (1 f 4), generally undergo radical cyclization (4 f 6) on treatment with stannyl
radicals. The products (6) can themselves be converted into allylic alcohols, so that the annulation
sequence can then be repeated. In certain cases enyne cyclization initiated by stannyl radicals
does not work, but an alternative process (cf. Scheme 9) of epoxide opening with bis(cyclopenta-
dienyl)titanium(III) chloride can then be used. Di- and triquinanes (Scheme 3) were made by the
stannyl radical approach; the epoxide route was used to prepare a simple propellane (Scheme 4)
and in a synthesis of (()-ceratopicanol (Schemes 5 and 9).
Sch em e 1
We report a procedure for fusing a five-membered ring
onto a cyclic allylic alcohol.1 The method, which is an
iterative one, has been used to construct members of the
triquinane class; a slight modification gave a propellane,
and the modified procedure was used to synthesize the
sesquiterpene (()-ceratopicanol.
The principle of our method is summarized in Scheme
1. An allylic alcohol (1) can be converted by Claisen
rearrangement (1 f 2 f 3) and then by homologation (3
f 4) into an enyne in which the acetylenic chain is on
the same face as the original hydroxyl. Treatment with
stannyl radicals gives a vinyl stannane (4 f 5 f 6),
which is convertible into a ketone (6 f 7). Since ketones
may be easily desaturated and reduced, compounds of
type 7 are synthetically equivalent to allylic alcohols 8.
Stereochemical inversion would serve to convert 8 into
its epimer 9. Both 8 and 9 are members of the allylic
alcohol class used to begin the sequence, so that, in
principle, repetition of the whole process would result in
annulation of an additional ring on the same face as the
new hydroxyl. There is also the possibility of subjecting
allylic alcohols 8 and 9 to 1,3-transposition2 so as to fuse
the next ring on a different edge of the substrate.
We initially sought to implement this plan along the
lines shown in Scheme 2, but found that homologation
of 16 was difficult, as both the derived tosylate and
bromide were inert to displacement by lithium acetylide
under several different conditions. Presumably, this low
reactivity is due to the electron-withdrawing methoxy
substituent, whose purpose was to facilitate formation
of a 2,3-double bond in 18. In any event, we did not
pursue the matter, as we quickly found another route
(Scheme 3), in which the 2,3-double bond is formed by
standard methods for ketone desaturation.
Diol 19 was monosilylated (19 f 20) and the resulting
alcohol subjected to Mitsunobu inversion (20 f 21 f 22),
each step giving the expected product in at least 90%
yield. Formation of the vinyl ether 23, by treatment with
ethyl vinyl ether in the presence of mercuric acetate3
(99%) and thermolysis (200 °C), then gave aldehyde 24
(90%). In this series, the purpose of the t-BuMe2SiO
group is simply to raise the molecular weight of early
intermediates so that product isolation is simplified, and
the reason for using the inverted alcohol 22 rather than
the initial alcohol 20 is that preliminary experiments on
the Claisen rearrangement step (cf. 23 f 24) did not
work with material derived from 20.4
X Abstract published in Advance ACS Abstracts, February 15, 1996.
(1) Preliminary communications: (a) Clive, D. L. J .; Manning, H.
W. J . Chem. Soc., Chem. Commun. 1993, 666. (b) Clive, D. L. J .;
Magnuson, S. R. Tetrahedron Lett. 1995, 36, 15.
(2) Cf. (a) Wharton, P. S.; Bohlen, D. H. J . Org. Chem. 1961, 26,
3615. (b) Dupuy, C.; Luche, J . L. Tetrahedron 1989, 45, 3437. (c)
Discordia, R. P.; Murphy, C. K.; Dittmer, D. C. Tetrahedron Lett. 1990,
31, 5603. (d) Liotta, D.; Zima, G.; Saindane, M. J . Org. Chem. 1982,
47, 1258. (e) Barton, D. H. R.; Hay Motherwell, R. S.; Motherwell, W.
From 24, the required homologation to enyne 27 was
easily achieved by reduction (LiAlH4, 89%), replacement
B. J . Chem. Soc., Perkin Trans.
Yamamoto, H.; Nozaki, H. Bull. Chem. Soc. J pn. 1979, 52, 1757. (g)
Dauben, W. G.; Michno, D. M. J . Org. Chem. 1977, 42, 682.
1 1981, 2363. (f) Yasuda, A.;
(3) Watanabe, W. H.; Conlon, L. E. J . Am. Chem. Soc. 1957, 79,
2828.
0022-3263/96/1961-2095$12.00/0 © 1996 American Chemical Society

2096 J . Org. Chem., Vol. 61, No. 6, 1996
Clive et al.
Sch em e 2a
Sch em e 3a
a
All compounds are racemic.
of the resulting hydroxyl group by bromine (Ph3P/CBr4;6
96%), and nucleophilic displacement (89% yield) with
lithium acetylide (24 f 25 f 26 f 27). Treatment of
27 with Bu3SnH in the presence of Et3B and air7 then
served to generate the cyclization product 28.8 This
suffered protodestannylation9 during flash chromatog-
raphy, so that olefin 29 was isolated directly from this
experiment (76%; 85% after correction for recovered 27).
In order to prepare for the second iteration of the whole
process, the double bond in 29 was cleaved, and this was
best done by two standard steps: vicinal dihydroxylation
with OsO410 followed by glycol cleavage with Pb(OAc)4.11
The Lemieux-J ohnson procedure12 for double bond cleav-
age was also tried, but in this particular case, better
yields (92% overall) are obtained by the two-step method.
We had anticipated that standard selenoxide fragmenta-
tion would then lead to the unsaturated ketone 31, but
phenylselenenylation of 30 was very troublesome and
inefficient. Oxidation of the triethylsilyl enol ether
derived from 30 (LDA; Et3SiCl), using Pd(OAc)2,13 gave
enone 31 in 42% yield (from the enol ether). Fortunately,
benzenesulfenylation of 30 proceeded smoothly,14 and
a
TBS ) t-BuMe2Si. Key: (a) NaH, t-BuMe2SiCl, 96%; (b) Ph3P,
PhCOOH, DEAD, 97%; (c) LiAlH4, 94%; (d) Hg(OAc)2, ethyl vinyl
ether, 99%; (e) 200 °C, 90%; (f) LiAlH4, 89%; (g) Ph3P, CBr4, 96%;
(h) lithium acetylide, THF, HMPA, 89%; (i) Bu3SnH, Et3B, air, (j)
silica, 85% from 27; (k) OsO4, NMO, 99%; Pb(OAc)2, K2CO3, 93%;
(l) LDA, PhSSPh; MCPBA, 73%; (m) NaBH4, CeCl3‚7H2O, 91%;
(n) NaOAc, Hg(OAc)2, methyl vinyl ether, 72%; (o) i-Bu3Al; (p) in
situ reduction by i-Bu3Al, 95% from 33; (q) Ph3P, CBr4, 96%; (r)
lithium acetylide, THF, HMPA, 93%; (s) Bu3SnH, AIBN, PhMe,
reflux, 79%.
(4) Only a superficial study of thermal methods was made with the
series from 20, using a sulfoxide-based approach (cf. ref 5) or the
mercuric ion mediated vinylation employed successfully for 22 f 23
f 24 (cf. ref 3). We did not establish whether Claisen rearrangement
catalyzed by i-Bu3Al, as used with 33, would work in the series from
20.
(5) Mandai, T.; Ueda, M.; Hasegawa, S.; Kawada, M.; Tsuji, J .
Tetrahedron Lett. 1990, 31, 4041.
(6) Downie, I. M.; Holmes, J . B.; Lee, J . B. Chem. Ind. (London)
1966, 900.
oxidation with m-CPBA, followed by thermolysis in
refluxing decalin, converted 30 satisfactorily into 31 (73%
overall). Reduction of the enone by NaBH4 in the
presence of CeCl3‚6H2O gave, as expected, allylic alcohol
32 (91%) having the hydroxyl endo to the convex bicyclic
system.
With 32 in hand, we had a choice of proceeding directly
with a second annulation or first inverting the stereo-
chemistry of the hydroxyl. We decided to preserve the
stereochemistry of 32 since annulation would then have
to occur on the more hindered face of the substrate and
might therefore be a somewhat more demanding test
than annulation on the other face. Accordingly, alcohol
32 was converted into its vinyl ether 33. The hydroxyl
in 32 proved to be decidedly hindered, and vinylation in
the presence of ethyl vinyl ether and Hg(OAc)2 was very
slow. However, by using a long reaction time (48 h as
compared with 18 h for 22) and a reaction medium
buffered by sodium acetate,3 it was possible to isolate the
required vinyl ether 32 in 91% yield (cf. 99% for 23).
(7) (a) Nozaki, K.; Oshima, K.; Utimoto, K. J . Am. Chem. Soc. 1987,
109, 2547. (b) Nozaki, K.; Oshima, K.; Utimoto, K. Bull. Chem. Soc.
J pn. 1987, 60, 3465. (c) Nozaki, K.; Oshima, K.; Utimoto, K. Tetrahe-
dron Lett. 1988, 29, 6127. (d) Nozaki, K.; Oshima, K.; Utimoto, K.
Tetrahedron 1989, 45, 923. (e) Barton, D. H. R.; J ang, D. O.; J aszber-
enyi, J . Cs. Tetrahedron Lett. 1990, 31, 4681.
(8) We did not establish if the material is a mixture of both Z and
E isomers or is just one isomer.
(9) Cf. Stork, G.; Mook, R. J . Am. Chem. Soc. 1987, 109, 2829.
(10) (a) Schro¨der, M. Chem. Rev. 1980, 80, 187. (b) VanRheenen,
V.; Kelly, R. C., Cha, D. Y. Tetrahedron Lett. 1976, 1973.
(11) Criegee, R.; Ho¨ger, E.; Huber, G.; Kruck, P.; Marktscheffel, F.;
Schellenberger, A. Ann. 1956, 599, 81.
(12) Pappo, R.; Allen, D. S., J r.; Lemieux, R. U.; J ohnson, W. S. J .
Org. Chem. 1956, 21, 478.
(13) Ito, Y.; Hirao, T.; Saegusa, T. J . Org. Chem. 1978, 43, 1011.
(14) Trost, B. M.; Salzmann, T. N.; Hiroi, K. J . Am. Chem. Soc. 1976,
98, 4887.

Routes to Triquinane and Propellane Systems
J . Org. Chem., Vol. 61, No. 6, 1996 2097
Sch em e 4
Claisen rearrangement of 33 was expected to be trouble-
some, after the problems experienced in its preparation;
in the event, extensive decomposition occurred under the
conditions (refluxing decalin) that had been very suc-
cessful with the simpler vinyl ether 23. However, a fine
alternative to thermal Claisen rearrangement is available
in the form of catalysis by aluminum alkyls,15 and in fact,
when 33 was treated with i-Bu3Al16 at -78 °C, alcohol
35sthe result of rearrangement (33 f 34) and in situ
reductionswas isolated in well over 90% yield. Bromide
36 was next prepared, and the halogen was displaced
with lithium acetylide to afford enyne 37 in 89% overall
yield from 35. The enyne seemed to be inert to the
conditions used previously for cyclization of 27, but when
the reaction was initiated with AIBN in refluxing toluene,
the triquinane 38 was isolated in 79% yield, after
destannylation on silica gel.
Formation of 38 took the route to a point where it
overlaps with a compound type used in an earlier step
(cf. 29), and so we next tried to extend the method to the
preparation of propellanes.17
Accordingly, enone 3918 was reduced (92%), and the
resulting alcohol was converted into aldehyde 42 (Scheme
4). This was best achieved19 (60% yield) by condensation
with phenyl vinyl sulfoxide5 (40 f 41) followed by
thermolysis (5 days at 180 °C) (41 f 42). From this
point, reduction (42 f 43; 92%), replacement of the
hydroxyl by bromine (43 f 44; 92%), bromide displace-
ment with lithium (trimethylsilyl)acetylide, and desilyl-
ation gave 45 (78% overall), the substrate for radical
closure. When this compound was treated with Ph3SnH
and AIBN in refluxing benzene, three inseparable prod-
ucts were obtained, after destannylation on silica gel. We
suspect, on the basis of 13C NMR measurements, that the
structures correspond to 46 and 47, but the topic was
With the above experiments, especially those of Scheme
3, as background, we next sought to apply the tandem
Claisen rearrangement/enyne radical closure to the
synthesis of (()-ceratopicanol 54,21 a substance that we
thought would be readily accessible by this methodology.
not pursued because related work on ceratopicanol (see
later) had suggested an alternative method for radical
closure of our enynes. Epoxidation of 45 with dimeth-
yldioxirane gave 48 as a mixture of stereoisomers (84%),
and when this material was treated with bis(cyclopen-
tadienyl)titanium(III) chloride,20 the desired products of
radical cyclization, 51 (28%) and 52 (48%) (tentative
stereochemical assignments, see the Experimental Sec-
tion) were easily obtained via the presumed intermedi-
ates 49 and 50. The alcohols could be separated, but the
mixture was also oxidized directly (88%) to a single
ketone (53).
The isolation22 of ceratopicanol is of interest in the
context of biogenetic theory, as the structure represents
evidence for generation in vivo of carbonium ion 55, a
species suggested23 to be a precursor to hirsutene and
related natural products.
Our synthesis of racemic ceratopicanol begins with the
known enone 56,24 which was reduced (56 f 57, DIBAL-
H, 89%, Scheme 5) and then subjected to conditions of
Mitsunobu inversion. This inversion process proved to
be somewhat troublesome and, of several procedures that
(15) (a) Takai, K.; Mori, I.; Oshima, K.; Nozaki, H. Tetrahedron Lett.
1981, 22, 3985. (b) Cf. Nonoshita, K.; Maruoka, K.; Yamamoto, H.;
Bull. Chem. Soc. J pn. 1992, 65, 541. (c) For palladium catalysis, see,
for example: Sugiura, M.; Yanagisawa, M.; Nakai, T. Synlett 1995,
447.
(16) Paquette, L. A.; Friedrich, D.; Rogers, R. D. J . Org. Chem. 1991,
56, 3841.
(17) Review on propellanes: Ginsberg, D. Top. Curr. Chem. 1987,
137, 1.
(18) Rae, I. D.; Umbrasas, B. N. Aust. J . Chem. 1975, 28, 2669.
(19) Reaction of alcohol 40 with ethyl vinyl ether/Hg(OAc)2 was very
slow, and the yield varied from run to run; therefore, the sulfoxide
route was examined.
(20) Cf. RajanBabu, T. V.; Nugent, W. A. J . Am. Chem. Soc. 1994,
116, 986.
(21) For synthesis of the unnatural antipode, see: Mehta, G.; Karra,
S. R. J . Chem. Soc., Chem. Commun. 1991, 1367.
(22) Hanssen, H.-P.; Abraham, W.-R. Tetrahedron 1988, 44, 2175.
(23) (a) Hayano, K.; Ohfune, Y.; Shirahama, H.; Matsumoto, T. Helv.
Chim. Acta 1981, 64, 1347. (b) Comer, F. W.; McCapra, F.; Qureshi, I.
H.; Scott, A. I. Tetrahedron 1967, 23, 4761.
(24) Tobe, Y.; Yamashita, D.; Takahashi, T.; Inata, M.; Sato, J .;
Kakiuchi, K.; Kobiro, K.; Odaira, Y. J . Am. Chem. Soc. 1990, 112, 775
and references cited therein.

2098 J . Org. Chem., Vol. 61, No. 6, 1996
Clive et al.
Sch em e 5
Sch em e 6
rate of bimolecular hydrogen abstraction from stannane
by the hindered radical 67 is slow, rearrangement of 67
to 66 need not be unusually fast; however, we were
unable to rule out the possibility that formation of 66 is
an example of kinetically preferred direct 6-endo clo-
sure.28 For example, use of a higher stannane concentra-
tion (1.1 M) still gave 66 (and not the desired compound),
as well as hydrostannylation products of the triple bond
and, when we did the experiment in the presence29 of a
trace of PhSeSePhsin the hope of trapping 67-the
outcome was unchanged.
It is not clear why anomalous behavior is observed in
this case, since several examples are known in which
vinyl radicals cyclize onto proximally substituted non-
conjugated double bonds,9,30 but in any event, we were
forced to modify the approach, and we now tried to
generate the radical at a different position so that closure
would occur onto the triple bond.
Alcohol 61 was elaborated into thionocarbonates 77a
and 77b by the route summarized in Scheme 7. The
intermediate diols 70a and 70b were separated and
individually converted into the corresponding thionocar-
bonates. Our stereochemical assignments to the diols
were made on the basis of proton NMR coupling con-
stants in the hydroxy ketones 72a and 72b. The syn-
thetic route for 77a is shown in detail in Scheme 7; the
same route was used to make 77b. Unfortunately,
reduction of 77a or 77b with Ph3SnH or Bu3SnH gave
quite complex mixtures under what we judged to be
appropriate and standard conditions for radical cycliza-
tion, and products of the desired type did not appear to
be presentsat least as judged by 200 MHz 1H NMR
spectra of the reaction mixtures. It would have been not
only helpful to us, but also interesting, to have obtained
readily isolable products, because some work has been
reported31 on stannane reduction of unsymmetrical thion-
ocarbonates, and formation of either the less substituted
or the more substituted radicalsas we had wanted (cf.
Scheme 8)shas been observed. However, exactly what
controls the regiochemistry is not fully understood, and
the status (primary, secondary, or tertiary) of the poten-
we tried,25 only the use of chloroacetic26 acid, followed
by reduction (LiAlH4), gave an acceptable result (58%
overall). As in our earlier studies (Schemes 3 and 4), exo
alcohol 58 was next converted into the derived vinyl enol
ether and then into the product of Claisen rearrangement
and reduction (61). These modifications could be ac-
complished by exchange with ethyl vinyl ether and
catalyzed (i-Bu3Al) rearrangement, followed by in situ
reduction, but were more reliably done (73% overall) by
addition to phenyl vinyl sulfoxide, thermal rearrange-
ment (150 °C), and reduction (LiAlH4) (58 f 59 f 60 f
61). Alcohol 61 was converted efficiently (96%) into the
corresponding bromide (62), again using Ph3P/CBr4, and
the halogen was displaced with lithium (trimethylsilyl)-
acetylide. Desilylation with methanolic sodium hydrox-
ide then gave the key enyne 64 in excellent overall yield
(94% from bromide 62).
When the enyne was treated with Bu3SnH (0.01-0.07
M) in refluxing benzene, with AIBN as an initiator, only
alkene 66 was isolated after exposure to silica gel (for
protodestannylation). The compound was a single ste-
reoisomer, but the relative stereochemistry at the starred
atom was not established.
Formation of 66 could occur either by direct 6-endo
closure, or by the normal 5-exo pathway (65 f 67)
(Scheme 6), as observed in our model studies (see Scheme
3), followed by rearrangement27 (67 f 68 f 66). If the
(27) (a) Beckwith, A. L. J .; O’Shea, D. M. Tetrahedron Lett. 1986,
27, 4525. (b) Stork, G.; Mook, R., J r. Tetrahedron Lett. 1986, 27, 4529.
(c) Denis, R. C.; Rancourt, J .; Ghiro, EÄ .; Boutonnet, F.; Gravel, D.
Tetrahedron Lett. 1993, 34, 2091.
(28) (a) Cf. Berkowitz, W. F.; Wilson, P. J . J . Org. Chem. 1991, 56,
3097. (b) Cf. Kataoka, T.; Yoshimatsu, M.; Noda, Y.; Sato, T.; Shimizu,
H.; Hori, M. J . Chem. Soc., Perkin Trans. 1 1993, 121.
(29) Crich, D.; Yao, Q. J . Org. Chem. 1995, 60, 84.
(30) E.g. (a) Stork, G.; Baine, N. H. J . Am. Chem. Soc. 1982, 104,
2321. (b) Stork, G.; Mook, R., J r. J . Am. Chem. Soc. 1983, 105, 3720.
(c) Cf. Broka, C. A.; Reichert, D. E. C. Tetrahedron Lett. 1987, 28, 1503.
(31) E.g. (a) Barton, D. H. R.; Subramanian, R. J . Chem. Soc., Perkin
Trans. 1 1977, 1718. (b) Redlich, H.; Sudau, W.; Paulsen, H. Tetrahe-
dron 1985, 41, 4253. (c) Ziegler, F. E.; Zheng, Z. J . Org. Chem. 1990,
55, 1416 and references cited therein.
(25) Cf. Martin, S. F.; Dodge, J . A. Tetrahedron Lett. 1991, 32, 3017.
We did not try the methods reported in: Tsunoda, T.; Yamamiya, Y.;
Kawamura, Y.; Itoˆ, S. Tetrahedron Lett. 1995, 36, 2529.
(26) Sa¨ıah, M.; Bessodes, M.; Antonakis, K. Tetrahedron Lett. 1992,
33, 4317.

Routes to Triquinane and Propellane Systems
J . Org. Chem., Vol. 61, No. 6, 1996 2099
Sch em e 7
Sch em e 9a
Sch em e 8
a
Compound 80R has oxygen anti to acetylenic chain; 80â has
the oxygen syn to the acetylenic chain.
manipulations. Radical deoxygenation of 83R or 83â by
means of the corresponding phenoxythiocarbonyl esters33
gave the rearranged olefin 66, but rearrangement could
be avoided in the following way: Alcohols 83R and 83â
were individually acetylated, giving 84R (95%) and 84â
in (95%), dihydroxylated with OsO4, and hydrolyzed
(MeOH, K2CO3). The resulting triols (not shown in
Scheme 9) responded in the normal way to the action of
Pb(OAc)4, affording hydroxy ketones 85R and 85â in 80%
and 75% yield, respectively, from the initial acetates.
Each alcohol was then deoxygenated by conversion into
its phenoxythiocarbonyl ester (85R f 86R, 84%; 85â f
86â, 74%), followed by treatment with Bu3SnH in the
presence of Et3B and air7 (86R f 87, 72%; 86â f 87,
73%). When deoxygenation was attempted using initia-
tion by AIBN in refluxing toluene, appreciable ring
expansion occurred,34 but the milder borane-mediated
procedure was satisfactory. Finally, reduction with
NaBH4 (81%) gave crystalline (()-ceratopicanol.
tial carbon radical product is evidently not the only
important factor.
Fortunately, radical cyclization was soon easily ac-
complished, after we recognized that an epoxide can be
made to behave (Scheme 9) in a manner appropriate for
the task in hand.
Epoxidation of enyne 64 with m-CPBA gave two
separable epoxides, 80R (oxygen anti to the acetylenic
chain, 75%) and 80â (oxygen syn to the acetylenic chain,
ca. 25%).32 Each compound was treated with bis(cyclo-
pentadienyl)titanium(III) chloride20 to afford the products
of radical cyclization 83R (82%) and 83â (81%), respec-
tively, as anticipated on the basis of the mechanism
shown. From this point, a little experimentation was
required to find the best way of performing the last few
(32) In the preliminary communication (ref 1b) footnote a of Scheme
2 should refer to the anti isomer, and footnote b should refer to the
syn isomer. Stereochemical assignments to the epoxides were made
by NOE measurements on the derived ketone 85â (see the Experi-
mental Section for 85â).
(33) Robins, M. J .; Wilson, J . S.; Hansske, F. J . Am. Chem. Soc.
1983, 105, 4059.
(34) Cf. Dowd, P.; Zhang, W. Chem. Rev. 1993, 93, 2091.

2100 J . Org. Chem., Vol. 61, No. 6, 1996
Clive et al.
dropwise (ca. 5 min), and stirring was continued for 4 h. The
solvent was evaporated, and flash chromatography of the
residue over silica gel (4 × 15 cm), using 5% EtOAc-hexane,
gave benzoate 21 (748.1 mg, 97%) as a pure (TLC, silica, 5%
Exp er im en ta l Section
Argon was purified by passage through a column (3.5 × 42
cm) of BASF R-311 catalyst and then through a similar column
of Drierite. Glassware was dried in an oven for at least 3 h
before use (120 °C) and either cooled in a desiccator over
Drierite or assembled quickly, sealed with rubber septa, and
EtOAc-hexane), colorless oil: FTIR (CH2Cl2 cast) 1719 cm-1
;
1H NMR (CDCl3 200 MHz) δ 0.10 (s, 6 H), 0.92 (s, 9 H), 2.10-
2.38 (m, 2 H), 5.07-5.16 (m, 1 H), 5.98-6.11 [m, 3 H (contains
singlet at δ 6.08)], 7.35-7.58 (m, 3 H), 7.96-8.06 (m, 2 H);
13C NMR (CDCl3 50.3 MHz) δ -4.66, 18.19, 25.87, 41.16, 76.33,
76.41, 128.27, 129.55, 130.40, 131.46, 132.85, 141.05, 166.49;
exact mass m/ z calcd for C18H26O3Si 318.1651, found 318.1650.
Anal. Calcd for C18H26O3Si: C, 67.88; H, 8.23. Found: C,
68.13; H, 8.39.
allowed to cool under
a slight static pressure of argon.
Reaction mixtures were stirred by Teflon-coated magnetic
stirring bars.
Solvents for chromatography or extractions were distilled
before use. Petroleum ether refers to the fraction bp 35-60
°C.
Products were isolated from solution by evaporation under
water pump vacuum at, or below, 30 °C, using a rotary
evaporator.
Temperatures recorded for Kugelrohr distillations refer to
air-bath temperatures and are not true boiling points. The
values indicate the temperature at which the distillate begins
to condense in the receiving bulb.
tr a n s-(()-4-[[(1,1-Dim eth yleth yl)d im eth ylsilyl]oxy]-2-
cyclop en ten -1-ol (22). A solution of ester 21 (2.326 g, 7.30
mmol) in THF (10 mL) was added dropwise at room temper-
ature to a stirred suspension of LiAlH4 (554.4 mg, 14.61 mmol)
in THF (31 mL). Stirring was continued for 15 min, and then
the mixture was quenched by successive addition of water (0.6
mL), 15% aqueous NaOH (0.6 mL), and water (1.8 mL). The
resulting mixture was stirred at room temperature for 20 min
and filtered through a pad (5 × 3 cm) of Celite. The pad was
washed with EtOAc, and the combined filtrates were evapo-
rated. Flash chromatography of the residue over silica gel (5
× 15 cm), using first CH2Cl2 and then 10% EtOAc-CH2Cl2,
gave alcohol 22 (1.4755 g, 94%) as a pure (1H NMR, 200 MHz),
Melting points were determined on a Kofler block melting
point apparatus.
Commercial thin layer chromatography (TLC) plates (silica
gel, Merck 60F-254) were used. Spots were detected by
examination under UV light or by spraying the plate with a
solution of phosphomolybdic acid,35 followed by charring on a
hot plate. Silica gel for flash chromatography was Merck type
60 (230-400 mesh).
1
colorless oil: FTIR (CH2Cl2 cast) 3333 cm-1; H NMR (CDCl3
200 MHz) δ 0.05 (s, 6 H), 0.87 (s, 9 H), 1.80 (br s, 1 H), 1.97-
2.04 (m, 2 H), 4.94-5.10 (m, 2 H), 5.88-5.95 (m, 2 H); 13C NMR
(CDCl3 50.3 MHz) δ -4.62, 18.22, 25.92, 44.54, 76.24, 76.41,
135.55, 136.36; exact mass m/ z calcd for C11H22O2Si 214.1389,
found 214.1388. An analytical sample was prepared by
Kugelrohr distillation (111 °C, 15 mmHg). Anal. Calcd for
C11H22O2Si: C, 61.63; H, 10.34. Found: C, 61.61; H, 10.41.
tr a n s-(()-(1,1-Dim eth yleth yl)[[4-(eth en yloxy)-2-cyclo-
p en ten -1-yl]oxy]d im eth ylsila n e (23). Hg(OAc)2 (462.7 mg,
6.42 mmol) was added at room temperature to a solution of
alcohol 22 (1.3755 g, 6.42 mmol) in freshly distilled ethyl vinyl
ether (70 mL), and the resulting solution was refluxed for 18
h. Anhydrous K2CO3 (4.0 g) was added to the cooled mixture,
and the excess of ethyl vinyl ether was evaporated (water
pump). The residue was taken up in CH2Cl2 (50 mL) and
filtered through a pad (3 × 5 cm) of flash chromatography silica
gel, using first CH2Cl2 and then EtOAc. The CH2Cl2 filtrate
was evaporated to give vinyl ether 23 (1.234 g, 80%, 99% after
correction for recovered starting material) as a colorless oil
containing trace impurities (1H NMR, 200 MHz): FTIR (CH2-
Cl2 cast) 2955, 2930, 2857, 1640, 1611, 1370, 1254, 1192, 1178,
1124, 1072, 1040, 978, 904, 857, 836, 814, 775 cm-1; 1H NMR
(CDCl3 200 MHz) δ 0.08 (s, 6 H), 0.88 (s, 9 H), 1.96 (ddd, J )
14.5, 7.0, 4.0 Hz, 1 H), 2.20 (ddd, J ) 14.5, 7.0, 2.5 Hz, 1 H),
4.01 (dd, J ) 6.5, 2.0 Hz, 1 H), 4.21 (dd, J ) 14.0, 2.0 Hz, 1
H), 4.99-5.12 (m, 2 H), 5.95-6.04 (m, 2 H), 6.35 (dd, J ) 14,
6.5 Hz, 1 H); 13C NMR (CDCl3 50.3 MHz) δ -4.64, 18.19, 25.91,
41.01, 76.45, 82.34, 88.16, 131.67, 140.22, 150.57; exact mass
m/ z calcd for C13H24O2Si 240.1545, found 240.1549. A satis-
factory combustion analysis could not be obtained.
Dry solvents were prepared under an inert atmosphere and
transferred by oven-dried syringes. Dry THF was distilled
from Na and benzophenone ketyl. Dry PhH was distilled from
Na. Dry i-Pr2NH, CH2Cl2, MeOH, pyridine, DMF, and HMPA
were distilled from CaH2, the last two solvents being distilled
under water pump vacuum. Commercial (Aldrich) solutions
of n-BuLi (in hexanes) were assumed to have the stated
molarity.
The symbols s′, d′, t′, and q′ used for 13C NMR spectra
indicate 0, 1, 2,or 3 attached protons.
cis-(()-4-[[(1,1-Dim eth yleth yl)d im eth ylsilyl]oxy]-2-cy-
clop en ten -1-ol (20). NaH (804.0 mg, 60% w/w in oil, 20.10
mmol) was washed with hexane (2 × 5 mL) and suspended in
THF (30 mL). A solution of diol 1936 (2.012 g, 20.10 mmol) in
THF (10 mL plus 2 mL as a rinse) was added dropwise to the
stirred suspension, and vigorous stirring was continued for 1
h. t-BuMe2SiCl (3.0283 g, 20.10 mmol) in THF (5 mL plus 2
mL as a rinse) was added, and stirring was continued
overnight. The mixture was poured into a solution of Et2O
(200 mL) and MeOH (50 mL), and the suspension was filtered
through a pad (5 × 3 cm) of flash chromatography silica gel.
The pad was washed with EtOAc (300 mL), and the filtrate
was evaporated. Flash chromatography of the residue over
silica gel (5 × 15 cm), using first 20% EtOAc-hexane and then
1:1:3 MeOH-EtOAc-hexane, gave unreacted diol 19 (205 mg,
10%) and alcohol 20 (3.705 g, 86%; 96% after correction for
recovered starting material) as a pure (TLC, silica, 20%
EtOAc-hexane), colorless oil: FTIR (CH2Cl2 cast) 3340 cm-1
;
1H NMR (CDCl3 200 MHz) δ 0.07 (s, 6 H), 0.88 (s, 9 H), 1.48
(ddd, J ) 14.0, 4.5, 4.5 Hz, 1 H), 2.19 (br s, 1 H), 2.66 (ddd,
14.0, 7.0, 7.0 Hz, 1 H), 4.51-4.67 (m, 2 H), 5.82-5.93 (m, 2
H); 13C NMR (CDCl3 50.3 MHz) (two signals overlap) δ -4.62,
18.17, 25.92, 44.74, 75.18, 135.64, 136.97; exact mass m/ z calcd
for C7H13O2Si (M - t-Bu) 157.0685, found 157.0682. An
analytical sample was prepared by Kugelrohr distillation (65
°C, 0.075 mmHg). Anal. Calcd for C11H22O2Si: C, 61.63; H,
10.34. Found: C, 61.43; H, 10.42.
Evaporation of the EtOAc filtrate gave the starting alcohol
22 (263.3 mg, 19%).
tr a n s-(()-5-[[(1,1-Dim eth yleth yl)d im eth ylsilyl]oxy]-2-
cyclop en ten e-1-a ceta ld eh yd e (24). A solution of vinyl ether
23 (1.153 g, 4.80 mmol) in decalin (30 mL) was refluxed (bath
temperature 200 °C) for 20 min. The mixture was cooled,
diluted with hexane (50 mL), and filtered through a pad (5 ×
3 cm) of flash chromatography silica gel. The pad was washed
with hexane (100 mL), and the filtrate was discarded. The
pad was then washed with EtOAc (200 mL), and the filtrate
was evaporated. Flash chromatography of the residue over
silica gel (4 × 14 cm), using 5% EtOAc-hexane, gave aldehyde
24 (1.042 g, 90%) as a pure (1H NMR, 200 MHz), colorless oil:
tr a n s-(()-4-[[(1,1-Dim eth yleth yl)d im eth ylsilyl]oxy]-2-
cyclop en ten -1-yl Ben zoa te (21). Ph3P (1.272 g, 4.85 mmol)
and benzoic acid (592.4 mg, 4.85 mmol) were added succes-
sively to a stirred solution of alcohol 20 (520 mg, 2.43 mmol)
in THF (20 mL) at room temperature. Diethyl azodicarboxyl-
ate (0.76 mL, 4.85 mmol) in THF (4 mL) was then added
1
FTIR (CH2Cl2 cast) 1727 cm-1; H NMR (CDCl3 200 MHz) δ
0.04 (s, 6 H), 0.87 (s, 9 H), 2.16-2.64 (m, 4 H), 2.92-3.06 (m,
1 H), 4.05 (ddd, J ) 7.0, 5.0, 5.0 Hz, 1 H), 5.56-5.71 (m, 2 H),
9.77 (t, J ) 2.5 Hz, 1 H); 13C NMR (CDCl3 50.3 MHz) δ -4.77,
-4.46, 18.00, 25.84, 41.38, 47.26, 48.83, 78.53, 129.19, 131.38,
201.64; exact mass m/ z calcd for C9H15O2Si (M - t-Bu)
(35) Phosphomolybdic acid (15 g) and ceric ammonium sulfate (2.5
g) dissolved in a mixture of water (985 mL) and concentrated sulfuric
acid (15 mL).
(36) Kaneko, C.; Sugimoto, A.; Tanaka, S. Synthesis 1974, 876.

Routes to Triquinane and Propellane Systems
J . Org. Chem., Vol. 61, No. 6, 1996 2101
183.0841, found 183.0839. An analytical sample was prepared
by Kugelrohr distillation (55 °C, 0.005 mmHg). Anal. Calcd
for C13H24O2Si: C, 64.95; H, 10.06. Found: C, 65.07; H, 9.86.
tr a n s-(()-5-[[(1,1-Dim eth yleth yl)d im eth ylsilyl]oxy]-2-
cyclop en ten e-1-eth a n ol (25). A solution of aldehyde 24
(299.5 mg, 1.25 mmol) in THF (4 mL plus 1 mL as a rinse)
was added at room temperature to a stirred suspension of
LiAlH4 (95 mg, 2.49 mmol) in THF (5 mL). The mixture was
stirred for 15 min and then quenched by successive addition
of water (0.1 mL), 15% aqueous NaOH (0.1 mL), and water
(0.3 mL). Stirring was continued for 30 min, and the mixture
was then filtered through a pad (3 × 2 cm) of Celite. The pad
was washed with EtOAc, and the combined filtrates were
evaporated. Flash chromatography of the residue over silica
gel (2 × 14 cm), using 15% EtOAc-hexane, gave alcohol 25
(269.2 mg, 89%) as a pure (TLC, silica, 15% EtOAc-hexane),
(1r,3a r,6a r)-(()-(1,1-Dim eth yleth yl)d im eth yl[octa h y-
d r o-4-m eth ylen e-1-p en ta len yl)oxy]sila n e (29). Et3B (1.0
M in hexane, 0.80 mL, 0.80 mmol) was added dropwise to a
stirred solution of enyne 27 (201.4 mg, 0.80 mmol) and Bu3-
SnH (0.27 mL, 1.00 mmol) in hexane (55 mL). The mixture
was stirred at room temperature for an arbitrary period of 3
h (protection from atmospheric moisture by a Drierite tube).
Evaporation of the solvent and flash chromatography of the
residue over silica gel (2 × 14 cm), using first hexane followed
by 10% CH2Cl2-hexane, gave olefin 29 (154.2 mg, 76%; 85%
after correction for recovered starting material) as a pure (1H
NMR, 200 MHz), colorless oil: FTIR (CH2Cl2 cast) 2954, 2936,
2930, 2894, 2857, 1472, 1462, 1361, 1255, 1179, 1122, 1092,
1
1063, 1025, 1006, 880, 866, 835, 774 cm-1; H NMR (CDCl3,
200 MHz) δ 0.02 (s, 3 H), 0.03 (s, 3 H), 0.87 (s, 9 H), 1.13-
1.91 (m, 5 H), 1.98-2.45 (m, 4 H), 2.86-3.02 (m, 1 H), 3.86
(dd, J ) 3.5, 3.5 Hz, 1 H), 4.73 (dddd, J ) 2.0, 2.0, 2.0, 2.0 Hz,
1 H), 4.81 (dddd, J ) 2.0, 2.0, 2.0, 2.0 Hz, 1 H); 13C NMR
(CDCl3, 50.3 MHz) δ -4.64, -4.54, 18.17, 25.94, 29.33, 30.79,
34.27, 34.94, 46.29, 53.43, 80.00, 104.19, 158.47; exact mass
1
colorless oil: FTIR (CH2Cl2 cast) 3346 cm-1; H NMR (CDCl3
200 MHz) δ 0.08 (s, 6 H), 0.88 (s, 9 H), 1.50-1.77 (m, 2 H),
2.06 (br s, 1 H), 2.15-2.30 (m, 1 H), 2.49-2.70 (m, 2 H), 3.6-
3.79 (m, 2 H), 4.04-4.16 (m, 1 H), 5.53-5.64 (m, 2 H); 13C NMR
(CDCl3 50.3 MHz) δ -4.71, -4.16, 18.04, 25.88, 36.31, 41.60,
51.19, 61.51, 79.52, 127.90, 132.89; exact mass m/ z calcd for
C9H17O2Si (M - t-Bu) 185.0998, found 185.0996. An analytical
sample was prepared by Kugelrohr distillation (120 °C, 14
mmHg). Anal. Calcd for C13H26O2Si: C, 64.41; H, 10.81.
Found: C, 64.74; H, 10.63.
m/ z calcd for
C15H28OSi 252.1909, found 252.1905. An
analytical sample was prepared by Kugelrohr distillation (126
°C, 14 mmHg). Anal. Calcd for C15H28OSi: C, 71.36; H, 11.18.
Found: C, 71.51; H, 11.15.
(3a r,4r,6a r)-(()-4-[[(1,1-Dim eth yleth yl)d im eth ylsilyl]-
oxy]h exa h yd r o-1(2H)-p en ta len on e (30). OsO4 (2.5 w/w %
in 2-methyl-2-propanol, 3.4 mL, 0.27 mmol) was added drop-
wise to a stirred solution of olefin 29 (687.0 mg, 2.72 mmol) in
acetone (2.5 mL) and water (5.0 mL). 4-Methylmorpholine
N-oxide monohydrate (735.3 mg, 5.44 mmol) was added in one
portion, and stirring was continued for 3 h. The mixture was
saturated with MgSO4 and filtered through a pad (5 × 3 cm)
of flash chromatography silica gel, using EtOAc. Evaporation
of the filtrate and flash chromatography of the residue over
silica gel (3 × 15 cm), using 50% EtOAc-hexane, gave a
mixture (787.7 mg, 99%) of two diastereomeric diols in a 12:1
ratio (1H NMR, 200 MHz). The diastereomers were separated
by flash chromatography over silica gel (3 × 25 cm), using
EtOAc-hexane mixtures containing from 35 to 50% EtOAc.
The minor diastereoisomer had: FTIR (CH2Cl2 cast) 3385
cm-1; 1H NMR (CDCl3, 200 MHz) δ 0.03 (s, 6 H), 0.86 (s, 9 H),
1.18-1.88 (m, 8 H), 2.0 (br s, 2 H), 2.2-2.4 (m, 2 H), 3.48 (s,
2 H), 3.90 (m, 1 H); 13C NMR (CDCl3, 50.3 MHz) δ -4.64,
-4.55, 18.12, 23.56, 25.91, 27.52, 36.01, 36.46, 47.81, 52.86,
69.53, 80.49, 82.40; exact mass m/ z calcd for C15H30O3Si
286.1964, found 286.1966. An analytical sample was prepared
by Kugelrohr distillation (164 °C, 14 mmHg). Anal. Calcd
for C15H30O3Si: C, 62.89; H, 10.56. Found: C, 63.01; H, 10.52.
tr a n s-(()-[[2-(2-Br om oeth yl)-3-cyclop en ten -1-yl]oxy]-
(1,1-d im eth yleth yl)d im eth ylsila n e (26). Ph3P (582.5 mg,
2.22 mmol) and CBr4 (736.5 mg, 2.22 mmol) were added
successively to a cooled (0 °C) and stirred solution of alcohol
25 (269.2 mg, 1.11 mmol) in dry CH2Cl2 (15 mL). The cooling
bath was removed, and after 30 min, the mixture was filtered
through a pad (3 × 2 cm) of flash chromatography silica gel,
using CH2Cl2. Evaporation of the filtrate and flash chroma-
tography of the residue over silica gel (2 × 14 cm), using first
hexane and then 5% EtOAc-hexane, gave bromide 26 (326.4
mg, 96%) as a pure (1H NMR, 200 MHz), colorless oil: FTIR
(CH2Cl2 cast) 2955, 2929, 2895, 2857, 1472, 1256, 1110, 1086,
904, 875, 837, 775, 709 cm-1 1H NMR (CDCl3, 200 MHz) δ
;
0.05 (s, 3 H), 0.06 (s, 3 H), 0.84 (s, 9 H), 1.72-2.09 (m, 2 H),
2.15-2.29 (m, 1 H), 2.50-2.74 (m, 2 H), 3.42 (td, J ) 7.5, 1.0
Hz, 2 H), 4.06 (dt, J ) 7.0, 4.5 Hz, 1 H), 5.56-5.70 (m, 2 H);
13C NMR (CDCl3, 50.3 MHz) δ -4.64, -4.32, 18.07, 25.91,
31.39, 36.97, 41.69, 53.43, 78.60, 128.69, 131.38; exact mass
m/ z calcd for C9H16OBrSi (M - t-Bu) 247.0154, found 247.0148.
An analytical sample was prepared by Kugelrohr distillation
(110 °C, 15 mmHg). Anal. Calcd for C13H25OBrSi: C, 51.14;
H, 8.25. Found: C, 51.27; H, 8.36.
tr a n s-(()-(1,1-Dim eth yleth yl)d im eth yl[[2-(3-bu tyn yl)-
3-cyclop en ten -1-yl]oxy]sila n e (27). Acetylene [purified by
passage through a cold trap (-78 °C), a bubbler containing
concentrated H2SO4, a tube (15 × 2 cm) packed with NaOH
pellets, and then a tube (26 × 1.5 cm) packed with Drierite]
was bubbled through cold (-78 °C) THF (10 mL) for 12 min.
n-BuLi (1.6 M in hexanes, 1.1 mL, 1.75 mmol) was added
dropwise, and the resulting mixture was stirred for 10 min.
Bromide 26 (178.3 mg, 0.58 mmol) in THF (2 mL plus 1 mL
as a rinse) was then added, followed by HMPA (1.0 mL). The
cooling bath was removed, and stirring was continued for 3 h.
The mixture was then quenched with saturated aqueous NH4-
Cl (10 mL) and extracted with EtOAc (3 × 20 mL). The
combined extracts were dried (MgSO4) and evaporated. Flash
chromatography of the residue over silica gel (3 × 15 cm), using
10% CH2Cl2-hexane, gave enyne 27 (130.5 mg, 89%) as a pure
(1H NMR, 200 MHz), colorless oil: FTIR (CH2Cl2 cast) 3313,
2955, 2929, 2889, 2857, 1472, 1463, 1361, 1256, 1111, 1093,
The major diastereoisomer had: FTIR (CH2Cl2 cast) 3376
cm-1; 1H NMR (CDCl3, 200 MHz) δ 0.02 (s, 3 H), 0.03 (s, 3 H),
0.70-0.98 (s, 9 H), 0.99-1.19 (m, 1 H), 1.30-2.20 [m 9 H
(includes br s at δ 1.95)], 2.35-2.58 (m, 2 H), 3.58 (d, J ) 11
Hz, 1 H), 3.67 (d, J ) 11 Hz, 1 H), 3.75-3.84 (m, 1 H); 13C
NMR (CDCl3, 50.3 MHz) -4.59, 18.08, 25.54, 25.87, 27.78,
33.92, 35.65, 51.26, 52.03, 66.96, 81.15, 84.89; exact mass m/ z
calcd for C15H30O3Si 286.1964, found 286.1965. Anal. Calcd
for C15H30O3Si: C, 62.89; H, 10.56. Found: C, 62.83; H, 10.61.
K2CO3 (127.8 mg, 0.92 mmol) and Pb(OAc)4 (273.3 mg, 0.62
mmol) were added successively to a stirred and cooled (0 °C)
solution of the above diols (88.3 mg, 0.31 mmol) in CH2Cl2 (10
mL). After 10 min the cold bath was removed and stirring
was continued for 50 min. The mixture was then filtered
through a pad (3 × 2 cm) of flash chromatography silica gel,
using EtOAc. Evaporation of the filtrate and flash chroma-
tography of the residue over silica gel (2 × 15 cm), using 5%
EtOAc-hexane, gave ketone 30 (73.0 mg, 93%) as a pure (1H
1
1071, 1006, 905, 875, 836, 815, 775, 710, 631 cm-1; H NMR
NMR, 200 MHz), colorless oil: FTIR (CH2Cl2 cast) 1740 cm-1
;
(CDCl3 200 MHz) δ 0.05 (s, 3 H), 0.06 (s, 3 H), 0.88 (s, 9 H),
1.39-1.76 (m, 2 H), 1.93 (t, J ) 2.6 Hz, 1 H), 2.14-2.27 (m, 3
H), 2.45-2.75 (m, 2 H), 4.05 (dt, J ) 6.7, 4.4 Hz, 1 H), 5.64 (s,
2 H); 13C NMR (CDCl3 50.3 MHz) δ -4.63, -4.35, 16.84, 18.11,
25.94, 32.32, 42.00, 53.80, 68.33, 78.50, 84.49, 128.41, 132.10;
exact mass m/ z calcd for C11H17OSi (M - t-Bu) 193.1049, found
193.1039. An analytical sample was prepared by Kugelrohr
distillation (105 °C, 14 mmHg). Anal. Calcd for C15H26OSi:
C, 71.93; H, 10.46. Found: C, 72.16; H, 10.60.
1H NMR (CDCl3, 200 MHz) δ 0.04 (s, 3 H), 0.06 (s, 3 H), 0.88
(s, 9 H), 1.36-1.82 (m, 4 H), 2.0-2.40 (m, 4 H), 2.54-2.76 (m,
2 H), 3.90-4.00 (m, 1 H); 13C NMR (CDCl3, 50.3 MHz) δ -4.78,
-4.63, 18.04, 23.97, 25.80, 26.52, 34.51, 37.96, 49.97, 50.12,
79.44, 222.64; exact mass m/ z calcd for C14H26O2Si 254.1702,
found 254.1696. An analytical sample was prepared by
Kugelrohr distillation (152 °C, 15 mmHg). Anal. Calcd for
C14H26O2Si: C, 66.09; H, 10.30. Found: C, 65.90; H, 10.48.

2102 J . Org. Chem., Vol. 61, No. 6, 1996
Clive et al.
(3a r,4r,6a r)-(()-4-[[(1,1-Dim eth yleth yl)d im eth ylsilyl]-
(1r,3aâ,4â,6aâ)-(()-(1,1-Dim eth yleth yl)[[4-(eth en yloxy)-
1,2,3,3a ,4,6a -h e xa h yd r o-1-p e n t a le n yl]oxy]d im e t h ylsi-
la n e (33). NaOAc (25.3 mg, 0.31 mmol) and Hg(OAc)2 (49.2
mg, 0.15 mmol) were added to a stirred solution of alcohol 32
(39.3 mg, 0.15 mmol) in freshly distilled ethyl vinyl ether (12
mL). The resulting suspension was refluxed for 48 h and then
cooled to room temperature. Anhydrous K2CO3 was added to
the mixture, and the excess of ethyl vinyl ether was evapo-
rated. The residue was taken up in 2:3 CH2Cl2-hexane and
filtered through a pad (2 × 3 cm) of flash chromatography silica
gel. The filtrate was evaporated to give vinyl ether 33 (26.8
mg, 72%) as a colorless oil containing trace impurities (1H
NMR, 200 MHz): FTIR (CH2Cl2 cast) 2955, 2929, 2886, 2857,
1635, 1610, 1472, 1463, 1362, 1320, 1254, 1193, 1157, 1093,
oxy]-4,5,6,6a -t et r a h yd r o-1(3a H)-p en t a len on e (31).37
A
solution of ketone 30 (198.9 mg, 0.78 mmol) in THF (2 mL
plus 1 mL as a rinse) was added to a stirred and cooled (-78
°C) solution of LDA [prepared by addition of n-BuLi (1.6 M in
hexanes, 0.98 mL, 1.56 mmol) to a stirred and cooled (-78
°C) solution of i-Pr2NH (0.22 mL, 1.56 mmol) in THF (10 mL)].
After 30 min the mixture was transferred by cannula to a
stirred solution of diphenyl disulfide (204.3 mg, 0.94 mmol)
in a mixture of THF (3 mL) and HMPA (1.0 mL). After 1.5 h
the mixture was poured into a separatory funnel containing
EtOAc (50 mL) and 0.5 M hydrochloric acid (10 mL). The
layers were shaken and separated, and the organic phase was
washed with saturated aqueous NaHCO3, dried (MgSO4), and
evaporated to give the crude sulfides as a yellow oil. The oil
was taken up in CH2Cl2 (15 mL), and solid NaHCO3 (120.0
mg, 1.43 mmol) was added. The mixture was cooled to -78
°C and m-CPBA (175.4 mg, 80-85%, 0.84 mmol) added in one
portion with stirring. The cold bath was removed and the
mixture allowed to attain room temperature. Additional
m-CPBA (55 mg and then 50 mg, 0.50 mmol total) was added
until all the sulfide had been oxidized (TLC control, silica, 10%
EtOAc-hexane). The mixture was poured into a separatory
funnel containing EtOAc (50 mL) and 10% aqueous Na2SO3
(10 mL). The organic layer was separated and washed with
saturated aqueous NaHCO3 (2 × 10 mL) and brine. The
combined aqueous washes were extracted once with EtOAc.
All the organic extracts were combined, dried (MgSO4), and
evaporated. The crude sulfoxides were taken up in PhMe (15
mL), and (MeO)3P (0.18 mL, 1.56 mmol) was added. The
resulting mixture was refluxed for 5 h, cooled, and filtered
through a pad (3 × 2 cm) of flash chromatography silica gel,
using hexane. The filtrate was discarded, and the pad was
washed with EtOAc. Evaporation of the resulting filtrate and
flash chromatography of the residue over silica gel (2 × 15
cm), using 5% EtOAc-hexane, gave enone 31 (143.1 mg, 73%)
as a pure (1H NMR, 200 MHz), colorless oil: FTIR (CH2Cl2
1055, 1005, 987, 961, 945, 907, 863, 834, 813, 775 cm-1 1H
;
NMR (CDCl3, 200 MHz) δ 0.03 (s, 3 H), 0.05 (s, 3 H), 0.87 (s,
9 H), 1.35-1.80 [m, 4 H (includes t at δ 1.71, J ) 5.0 Hz)],
2.89-3.13 (m, 2 H), 3.96-4.04 (m, 2 H), 4.24 (dd, J ) 14.0,
2.0 Hz, 1 H), 4.87 (dd, J ) 8.0, 1.5 Hz, 1 H), 5.68 (dt, J ) 5.5,
2.0 Hz, 1 H), 5.82 (dt, J ) 5.5, 2.0 Hz, 1 H), 6.43 (dd, J ) 14.0,
7.0 Hz, 1 H); 13C NMR (CDCl3, 50.3 MHz) δ -4.71, -4.59,
18.12, 23.01, 25.90, 35.21, 42.79, 60,86, 78.28, 84.09, 87.58,
131.20, 135.36, 151.45; exact mass m/ z calcd for C14H25OSi
(M - C2H3O) 237.1675, found 237.1670. A satisfactory com-
bustion analysis could not be obtained.
(1r,3a â,6â,6a â)-(()-6-[[(1,1-Dim eth yleth yl)d im eth ylsi-
lyl]oxy]-1,3a ,4,5,6,6a -h exa h yd r o-1-p en ta len eeth a n ol (35).
i-Bu3Al (1.0 M in PhMe, 0.38 mL, 0.38 mmol) was added to a
cooled (-78 °C) and stirred solution of vinyl ether 33 (26.8
mg, 0.096 mmol) in CH2Cl2 (4.0 mL). The cold bath was
removed, and after 1 h, the mixture was recooled to -78 °C
and quenched by addition of 0.5 M hydrochloric acid. The
mixture was then poured into a separatory funnel containing
0.5 M hydrochloric acid and EtOAc. The layers were sepa-
rated, and the aqueous phase was extracted with EtOAc. The
combined organic fractions were washed with brine, dried
(MgSO4), and evaporated. Flash chromatography of the
residue over silica gel (2 × 15 cm), using 10-15% EtOAc-
hexane, gave alcohol 35 (25.7 mg, 95%) as a pure (1H NMR,
1
cast) 1714 cm-1; H NMR (CDCl3, 200 MHz) δ 0.04 (s, 3 H),
0.06 (s, 3 H), 0.87 (s, 9 H), 1.24-1.46 (m,1 H), 1.48-1.63 (m,
1 H), 1.74-1.89 (m, 1 H), 2.02-2.27 (m, 1 H), 2.79 (ddd, J )
10.0, 5.5, 1.5 Hz, 1 H), 3.13-3.22 (m, 1 H), 4.10 (br d, J ) 4.0
Hz, 1 H), 6.10 (dd, J ) 5.5, 2.0 Hz, 1 H), 7.54 (dd, J ) 5.5, 3.0
Hz, 1 H); 13C NMR (CDCl3, 50.3 MHz) δ -4.82, -4.66, 18.04,
25.79, 26.68, 32.73, 48.62, 57.62, 75.09, 135.36, 163.88, 212.95;
exact mass m/ z calcd for C14H24O2Si 252.1545, found 252.1539.
An analytical sample was prepared by Kugelrohr distillation
(90 °C, 0.10 mmHg). Anal. Calcd for C14H24O2Si: C, 66.61;
H, 9.58. Found: C, 66.90; H, 9.36.
200 MHz), colorless oil: FTIR (CH2Cl2 cast) 3360 cm-1 1H
;
NMR (CDCl3, 200 MHz) δ 0.05 (s, 3 H), 0.06 (s, 3 H), 0.88 (s,
9 H), 1.16-1.73 (m, 4 H), 1.79-2.05 (m, 2 H), 2.05-2.33 (m, 1
H), 2.56 (td, J ) 8.5, 5.5 Hz, 1 H), 2.79-2.98 (m, 1 H), 3.11-
3.28 (m, 1 H), 3.61-3.88 (m, 2 H), 4.05 (q, J ) 6.0 Hz, 1 H),
5.41-5.53 (m, 2 H); 13C NMR (CDCl3, 50.3 MHz) δ -4.44,
-3.94, 18.04, 25.94, 27.81, 33.04, 35.36, 44.36, 48.94, 53.17,
63.02, 75.33, 132.83, 137.43; exact mass m/ z calcd for C12H21O2-
Si (M - t-Bu) 225.1311, found 225.1314.
(1r,3a r,6â,6a r)-(()-[[6-(2-Br om oe t h yl)-1,2,3,3a ,6,6a -
h exa h yd r o-1-p en ta len yl]oxy](1,1-d im eth yleth yl)d im eth -
ylsila n e (36). Ph3P (1.0467 g, 4.0 mmol) and CBr4 (1.324 g,
4.0 mmol) were added successively to a cooled (0 °C) and
stirred solution of alcohol 35 (563.7 mg, 2.0 mmol) in CH2Cl2
(25 mL). The cold bath was removed, and after 30 min, the
reaction mixture was filtered through a pad (3 × 2 cm) of flash
chromatography silica gel, using CH2Cl2. Evaporation of the
filtrate and flash chromatography of the residue over silica
gel (3 × 15 cm), using 5% CH2Cl2-hexane, gave bromide 35
(658.9 mg, 96%) as a pure (TLC, silica, 5% CH2Cl2-hexane),
colorless oil: FTIR (CH2Cl2 cast) 2954, 2929, 2884, 2856, 1742,
(1r,3a â,4â,6a â)-(()-4-[[(1,1-Dim eth yleth yl)d im eth ylsi-
lyl]oxy]-1,3a,4,5,6,6a-h exah ydr o-1-pen talen ol (32). NaBH4
(214.5 mg, 5.67 mmol) was added to a stirred and cooled (water
bath at room temperature) mixture of enone 31 (143.1 mg, 0.57
mmol) and CeCl3‚7H2O (211.2 mg, 0.57 mmol) in MeOH (10
mL). After 15 min, the reaction was quenched by addition of
water, and the mixture was extracted with EtOAc (3 × 25 mL).
The aqueous layer was acidified with 0.5 M hydrochloric acid
and extracted with EtOAc (1 × 25 mL). The combined organic
extracts were washed with brine, dried (MgSO4), and evapo-
rated. Flash chromatography of the residue over silica gel (2
× 15 cm), using 10% EtOAc-hexane, gave allylic alcohol 32
(131.4 mg, 91%) as a pure (1H NMR, 200 MHz), colorless oil:
1
1462, 1475, 1362, 1256, 1111, 1103, 1049, 836, 774 cm-1; H
NMR (CDCl3, 400 MHz) δ 0.05 (s, 3 H), 0.06 (s, 3 H), 0.88 (s,
9 H), 1.20-1.39 (m, 1 H), 1.47-1.65 (m, 2 H), 1.82-2.00 (m, 2
H), 2.12-2.23 (m, 1 H), 2.54 (td, J ) 8.5, 5.0 Hz, 1 H), 2.91-
3.00 (m, 1 H), 3.18-3.26 (m, 1 H), 3.45-3.59 (m, 2 H), 4.04
(ddd, J ) 5.0, 5.0, 5.0 Hz, 1 H), 5.47 (ddd, J ) 5.5, 2.0, 2.0 Hz,
1 H), 5.53 (ddd, J ) 5.5, 2.6, 2.6 Hz, 1 H); 13C NMR (CDCl3,
50.3 MHz) δ -4.52, -3.90, 17.97, 25.94, 28.02, 33.03, 34.17,
35.36, 45.93, 49.10, 52.74, 75.08, 131.22, 135.25; exact mass
m/ z calcd for C12H20OSiBr (M - t-Bu) 287.0467, found
287.0459.
(1r,3ar,6â,6ar)-(()-[[6-(3-Bu tyn yl)-1,2,3,3a,6,6a-h exah y-
d r o-1-p e n t a le n yl]oxy](1,1-d im e t h yle t h yl)d im e t h ylsi-
la n e (37). Acetylene [purified by passage through a cold trap
(-78 °C), a bubbler containing concentrated H2SO4, a tube (15
× 2 cm) packed with NaOH pellets, and then a tube (26 × 1.5
1
FTIR (CH2Cl2 cast) 3330 cm-1; H NMR (CDCl3, 200 MHz) δ
0.03 (s, 3 H), 0.05 (s, 3 H), 0.88 (s, 9 H), 1.43-1.85 (m, 5 H),
2.83-3.01 (m, 2 H), 3.98 (td, J ) 4.0, 1.5 Hz, 1 H), 4.77-4.86
(m, 1 H), 5.66 (dt, J ) 5.5, 2.0 Hz, 1 H), 5.78 (dt, J ) 5.5, 1.5
Hz, 1 H); 13C NMR (CDCl3, 50.3 MHz) δ -4.71, -4.60, 18.14,
22.78, 25.90, 35.54, 43.76, 60.90, 77.84, 78.42, 134.44, 134.57;
exact mass m/ z calcd for C10H17O2Si (M - t-Bu) 197.0998,
found 197.0993. An analytical sample was prepared by
Kugelrohr distillation (80 °C, 0.06 mmHg). Anal. Calcd for
C
14H26O2Si: C, 66.09; H, 10.30. Found: C, 65.89; H, 10.50.
(37) Cotterill, I. C.; Finch, H.; Highcock, R. M.; Holt, R. A.; Mahon,
M. F.; Molloy, K. C.; Morris, J . G.; Roberts, S. M.; Short, K. M.; Sik. V.
J . Chem. Soc., Perkin Trans. 1 1990, 1353.

Routes to Triquinane and Propellane Systems
J . Org. Chem., Vol. 61, No. 6, 1996 2103
cm) packed with Drierite] was bubbled through cold (-78 °C)
THF (30 mL) for 20 min. n-BuLi (1.6 M in hexanes, 3.6 mL,
5.72 mmol) was added dropwise, and the resulting mixture
was stirred for 15 min. Bromide 36 (658.9 mg, 1.91 mmol) in
THF (5 mL plus 2 mL as a rinse) was then added, followed by
HMPA (4 mL). The cooling bath was removed, and stirring
was continued for 1 h. The mixture was quenched with water
and extracted with hexane. The organic extract was dried
(MgSO4) and evaporated. Flash chromatography of the residue
over silica gel (3 × 15 cm), using 10% CH2Cl2-hexane, gave
enyne 37 (517.6 mg, 93%) as a pure (1H NMR, 200 MHz),
colorless oil: FTIR (CH2Cl2 cast) 3313, 2953, 2930, 2892, 2885,
2856, 2105, 1472, 1462, 1361, 1256, 1103, 1068, 1053, 1026,
1 h, EtOAc (50 mL) and water (50 mL) were added. The
aqueous phase was extracted with EtOAc until extraction was
complete (TLC control, silica, 1:1 EtOAc-hexane). The com-
bined organic extracts were washed with brine, dried (MgSO4),
and evaporated. Flash chromatography of the residue over
silica gel (3 × 20 cm), using 1:1 EtOAc-hexane, gave a mixture
of sulfoxide 41 and phenyl vinyl sulfoxide. This mixture was
not further purified, but was used directly in the next step.
(()-1,3,4,5,6,7-H exa h yd r o-4a (2H )-n a p h t h a len ea cet a l-
d eh yd e (42). NaHCO3 (35.63 g, 424 mmol) was added in one
lot to a stirred solution of sulfoxide 41 (mass unrecorded,
contaminated with phenyl vinyl sulfoxide) in dry, purified
decalin (50 mL). The suspension was heated at 180 °C for 5
days and then cooled to room temperature. EtOAc (100 mL)
and water (50 mL) were added, and the organic phase was
washed with brine, dried (MgSO4), and evaporated. Decalin
was removed by flash chromatography, using hexane, and the
desired compound was then eluted with EtOAc. Evaporation
of the EtOAc eluant, and flash chromatography of the residue
over silica gel (3 × 18 cm), using 15:85 CH2Cl2-hexane, gave
aldehyde 42 (1.182 g, 60% over two steps) as a pure (1H NMR,
1
1006, 836, 774, 632 cm-1; H NMR (CDCl3, 200 MHz) δ 0.02
(s, 3 H), 0.04 (s, 3 H), 0.88 (s, 9 H), 1.23-1.40 (m, 1 H), 1.40-
1.62 (m, 3 H), 1.73-2.02 [m, 3 H (includes t at δ 1.95, J ) 3.0
Hz)], 2.23-2.36 (m, 2 H), 2.52 (ddd, J ) 8.5, 4.5, 4.5 Hz, 1 H),
2.82-2.97 (m, 1 H), 3.14-3.29 (m, 1 H), 4.05 (ddd, J ) 4.5,
4.5, 4.5 Hz, 1 H), 5.49 (br s, 2 H); 13C NMR (CDCl3, 50.3 MHz)
δ -4.53, -3.99, 18.00, 18.17, 25.98, 28.27, 29.91, 35.28, 46.60,
49.50, 53.11, 68.39, 75.19, 84.56, 132.19, 134.64; exact mass
m/ z calcd for C14H21OSi (M - t-Bu) 233.1362, found 233.1363.
An analytical sample was prepared by Kugelrohr distillation
(118 °C, 11 mmHg). Anal. Calcd for C18H30OSi: C, 74.42; H,
10.41. Found: C, 74.56; H, 10.54.
(3r,3a r,3br,6a r,7a r)-(()-[(Deca h yd r o-6-m eth ylen e-1H-
cyclop en t a [a ]p en t a len -3-yl)oxy](1,1-d im et h ylet h yl)d i-
m eth ylsila n e (38). Bu3SnH (73 µL, 0.27 mmol) and AIBN
(4.2 mg, 0.026 mmol) were added to a solution of enyne 37
(58.1 mg, 0.20 mmol) in PhMe (10 mL), and the mixture was
refluxed for 45 min, cooled, and evaporated. Flash chroma-
tography of the residue over silica gel (2 × 16 cm), using 5%
CH2Cl2-hexane, gave olefin 38 (46.4 mg, 79%) as a pure (1H
NMR, 400 MHz), colorless oil: FTIR (CH2Cl2 cast) 2949, 2936,
2898, 2858, 1471, 1462, 1254, 1110, 1068, 1048, 1036, 901, 878,
854, 835, 774 cm-1; 1H NMR (CDCl3 400 MHz) δ 0.02 (s, 3 H),
0.03 (s, 3 H), 0.86 (s, 9 H), 0.92-1.02 (m, 1 H), 1.23-1.32 (m,
1 H), 1.32-1.48 (m, 1 H), 1.53-1.95 (m, 5 H), 2.25-2.37 (m, 1
H), 2.38-2.49 (m, 2 H), 2.53-2.73 (m, 2 H), 2.84 (dd, J ) 18.0,
9.0 Hz, 1 H), 4.05 (dd, J ) 8.0, 4.0 Hz, 1 H), 4.71-4.74 (m, 1
H), 4.76-4.79 (m, 1 H); 13C NMR (CDCl3 100.6 MHz) δ -4.7,
-4.4, 18.15, 25.96, 27.08, 29.32, 34.60, 37.16, 39.17, 45.85,
47.06, 52.80, 55.97, 76.14, 104.42, 156.39; exact mass m/ z calcd
for C18H32OSi, 292.2222, found 292.2218. An analytical sample
was prepared by Kugelrohr distillation (125 °C, 11 mmHg).
Anal. Calcd for C18H32OSi: C, 73.90; H, 11.03. Found: C,
73.76; H, 11.18.
(()-1,2,3,4,5,6,7,8-Octah ydr o-1-n aph th alen ol (40). CeCl3‚
7H2O (4.656 g, 12.50 mmol) was added to a stirred and cooled
(0 °C) solution of enone 3918 (1.562 g, 10.4 mmol) in MeOH
(100 mL). NaBH4 (0.985 g, 26.0 mmol) was added via a side-
arm addition tube over 15 min, and after 2 h, water (100 mL)
was added to the resulting white slurry. (Acid must be avoided
in the workup in order to prevent formation of a very nonpolar
UV-active compound.) The clear aqueous solution was ex-
tracted with EtOAc until extraction was complete (TLC
control, silica, 1:9 EtOAc-hexane). The combined organic
extracts were washed with brine, dried (MgSO4), and evapo-
rated. Flash chromatography of the residue over silica gel (3
× 20 cm), using 1:9 EtOAc-hexane, gave alcohol 40 (1.454 g,
92%) as a pure (1H NMR, 200 MHz), white solid: mp 51-53
°C; FTIR (CHCl3 cast) 3319 cm-1; 1H NMR (CDCl3, 200 MHz)
δ 1.20-2.05 (m, 14 H), 2.15-2.45 (m, 1 H), 3.90 (s, 1 H); 13C
NMR (CDCl3, 50.3 MHz) δ 18.2 (t′), 22.8 (t′), 23.0 (t′), 27.0 (t′),
30.3 (t′), 30.6 (t′), 32.2 (t′), 68.7 (d′), 129.9 (s′), 132.7 (s′); exact
mass m/ z calcd for C10H16O 152.1201, found 152.1200. Anal.
Calcd for C10H16O: C, 78.90; H, 10.59. Found: C, 79.01; H,
10.29.
200 MHz), colorless oil: FTIR (neat) 1719 cm-1 1H NMR
;
(CDCl3, 200 MHz) δ 1.10-2.35 (m, 14 H), 2.35-2.55 (dd, J )
14, 3 Hz, 1 H), 2.55-2.80 (dd, J ) 14, 3 Hz, 1 H), 5.40-5.60
(m, 1 H), 9.75-9.90 (dd, J ) 4.0, 2.6 Hz, 1 H); 13C NMR (CDCl3,
50.3 MHz) δ 18.7 (t′), 21.9 (t′), 25.3 (t′), 28.0 (t′), 32.2 (t′), 36.9
(t′), 37.6 (s′), 39.2 (t′), 48.3 (t′), 121.8 (d′), 140.8 (s′), 203.6 (d′);
exact mass m/ z calcd for C12H18O 178.1358, found 178.1361.
Anal. Calcd for C12H18O: C, 80.85; H, 10.18. Found: C, 80.54;
H, 10.14.
(()-1,3,4,5,6,7-H e xa h yd r o-4a (2H )-n a p h t h a le n e e t h a -
n ol (43). Aldehyde 42 (1.00 g, 5.62 mmol) in THF (10 mL)
was added to a stirred and cooled (-78 °C) suspension of
LiAlH4 (107 mg, 2.81 mmol) in dry THF (30 mL). The mixture
was allowed to warm to room temperature and then cooled to
0 °C. Water (10 mL) was added, and the aqueous solution
was extracted with EtOAc until extraction was complete (TLC
control, silica, 1:4 EtOAc-hexane). The combined organic
extracts were washed with brine, dried (MgSO4), and evapo-
rated. Flash chromatography of the residue over silica gel (3
× 18 cm), using 1:4 EtOAc-hexane, gave alcohol 43 (933 mg,
92%) as a pure (1H NMR, 200 MHz), colorless oil: FTIR (CHCl3
1
cast) 3316 cm-1; H NMR (CDCl3, 200 MHz) δ 1.05-1.35 (m,
3 H), 1.35-1.45 (s, 1 H), 1.45-1.82 (m, 8 H), 1.82-2.05 (m, 4
H), 2.05-2.40 (m, 1 H), 3.50-3.80 (dd, J ) 8.4, 7.6 Hz, 2 H),
5.30-5.50 (m, 1 H); 13C NMR (CDCl3, 50.3 MHz) δ 19.3 (t′),
22.1 (t′), 25.6 (t′), 28.4 (t′), 32.6 (t′), 36.1 (t′), 36.8 (s′), 37.6 (t′),
39.1 (t′), 59.5 (t′), 120.7 (d′), 143.3 (s′); exact mass m/ z calcd
for C12H20O 180.1514, found 180.1517. A satisfactory combus-
tion analysis could not be obtained.
(()-4a -(2-Br om oeth yl)-1,2,3,4,4a ,5,6,7-octa h yd r on a p h -
th a len e (44). CBr4 (1.398 g, 4.22 mmol) and Ph3P (1.106 g,
4.22 mmol) were added successively to a stirred and cooled (0
°C) solution of alcohol 43 (744 mg, 4.13 mmol) in dry CH2Cl2
(20 mL). The cold bath was removed, and stirring was
continued for 2.5 h. The clear solution was then filtered
through a short pad (4 × 3 cm) of flash chromatography silica
gel, using hexane to wash the residue completely out of the
silica. The organic solution was washed with brine, dried
(MgSO4), and evaporated. Flash chromatography of the
residue over silica gel (3 × 20 cm), using hexane, gave bromide
44 (928 mg, 92%) as a pure (1H NMR, 200 MHz), colorless oil:
FTIR (CH2Cl2 cast) 2926, 2854, 1456, 1445, 1215, 807, 630
cm-1; 1H NMR (CDCl3, 200 MHz) δ 1.05-1.40 (m, 3 H), 1.40-
1.85 (m, 7 H), 1.85-2.35 (m, 6 H), 3.15-3.50 (m, 2 H), 5.30-
5.50 (m, 1 H); 13C NMR (CDCl3, 50.3 MHz) δ 19.2 (t′), 22.0
(t′), 25.4 (t′), 28.2 (t′), 28.9 (t′), 32.3 (t′), 35.4 (t′), 38.3 (t′), 38.9
(t′), 39.0 (s′), 121.3 (d′), 141.7 (s′); exact mass m/ z calcd for
2-(1,2,3,4,5,6,7,8-Oct a h yd r on a p h t h a len -1-yloxy)et h yl
P h en yl Su lfoxid e (41). Alcohol 40 (1.670 g, 10.99 mmol) in
dry THF (15 mL) was added dropwise at room temperature to
a stirred suspension of NaH (80% suspension in mineral oil,
330 mg, 10.99 mmol) in dry THF (50 mL). After 30 min, a
solution of phenyl vinyl sulfoxide38 (5.02 g, 32.96 mmol) in dry
THF (10 mL) was added dropwise. A trace (ca. 1 mg) of KH
(35%w/w in mineral oil) was then added as a catalyst. After
C
12H1979Br 242.0671, found 242.0670. Anal. Calcd for C12H19
Br: C, 59.27; H, 7.88. Found: C, 59.17; H, 8.09.
-
(38) Paquette, L. A.; Carr, R. V. C. Organic Syntheses; Wiley: New
York, 1990; Collect. Vol. VII, p 453.

2104 J . Org. Chem., Vol. 61, No. 6, 1996
Clive et al.
(()-4a -(3-Bu tyn yl)-1,2,3,4,4a ,5,6,7-octa h yd r on a p h th a -
len e (45). n-BuLi (1.6 M in hexanes, 5.15 mL, 8.23 mmol)
was added over 5 min to a stirred and cooled (-78 °C) solution
of trimethylsilyl acetylene (2.021 g, 20.58 mmol) in dry THF
(20 mL). After 15 min, bromide 44 (500 mg, 2.06 mmol) in
dry THF (5 mL) was added dropwise. HMPA (2 mL) was
added, the cold bath was removed, and stirring was continued
for 8 h. NaOMe (2.0 M in MeOH, 20 mL, 40 mmol) was then
added with stirring, and after 2 h, the mixture was poured
into 1:1 hexane-water (50 mL). The aqueous layer was
extracted with hexane until extraction was complete (TLC
control, silica, hexane). The combined organic extracts were
washed with brine, dried (MgSO4), and evaporated. Flash
chromatography of the residue over silica gel (2 × 22 cm), using
hexane, gave acetylene 45 (302 mg, 78%) as a pure (1H NMR,
found 206.1670. A satisfactory combustion analysis could not
be obtained.
The more polar alcohol (51) showed no NOE between the
methinyl hydrogen and either vinyl hydrogen, whereas the less
polar isomer (52) showed a small (1%) NOE. On the assump-
tion of a chair conformation for the six-membered rings,
compound 51 would be expected to have the hydroxyl-bearing
carbon at lower field39 in the 13C NMR spectrum than 52. The
1H NMR signal for the methinyl hydrogen of 51 should be a
multiplet with one large (axial-axial) coupling; the corre-
sponding signal for 52 should contain only small couplings.
The NMR spectra show that these expectations are met and,
on this basis, the stereochemistry is tentatively assigned.
(1R*,6S*)-(()-11-Meth ylen etr icyclo[4.4.3.01,6]tr id eca n -
2-on e (53). A mixture of diastereomeric alcohols 51 and 52
(53.0 mg, 0.257 mmol) in dry CH2Cl2 (8 mL) was added at room
temperature to a stirred mixture of PCC (277 mg, 1.29 mmol)
and molecular sieves (4 Å, 92 mg) in dry CH2Cl2 (10 mL). After
2.5 h, the brown mixture was filtered through a pad (2 × 3
cm) of flash chromatography silica gel, CH2Cl2 being used to
wash the product completely out of the silica. Evaporation of
the filtrate and flash chromatography of the residue over silica
gel (1.5 × 17 cm), using 1:19 EtOAc-hexane, gave ketone 53
(46.0 mg, 88%) as a pure (1H NMR, 200 MHz), colorless solid:
mp 79-82 °C; FTIR (CHCl3 cast) 1702 cm-1; 1H NMR (CDCl3,
200 MHz) δ 0.90-1.65 (m, 9 H), 1.65-2.30 (m, 6 H), 2.35-
2.80 (m, 3 H), 4.40-4.65 (t, J ) 4.0 Hz, 1 H), 4.65-4.95 (t, J
) 4.0 Hz, 1 H); 13C NMR (50.3 MHz) δ 21.5 (t′), 21.8 (t′), 23.2
(t′), 28.4 (t′), 30.1 (t′), 30.9 (t′), 32.7 (t′), 34.0 (t′), 38.3 (t′), 49.8
(s′), 63.5 (s′), 106.7 (t′), 156.9 (s′), 212.3 (s′); exact mass m/ z
calcd for C14H20O 204.1514, found 204.1507. A satisfactory
combustion analysis could not be obtained.
(1r,3a â,6a â)-(()-1,3a ,4,5,6,6a -Hexa h yd r o-2,3,5,5-tetr a -
m eth yl-1-p en ta len ol (57). DIBAL (1 M in CH2Cl2, 4.3 mL,
4.3 mmol) was added dropwise over ca. 20 min to a cooled (0
°C) and stirred solution of enone 56 (385.1 mg, 2.16 mmol) in
CH2Cl2 (20 mL). After 2 h the solution was added dropwise
over ca. 30 min to a cooled (-78 °C) and stirred slurry of flash
chromatography silica gel (ca. 10 g) in CH2Cl2 (100 mL). The
cooling bath was removed, and when the temperature of the
mixture reached 0 °C, water (8 mL) was added. The mixture
was filtered through a pad (2 × 6 cm) of Celite, using CH2Cl2
as a rinse. Evaporation of the filtrate and flash chromatog-
raphy of the residue over silica gel (2.5 × 18 cm), using 10%
EtOAc-hexane, gave allylic alcohol 57 (349.3 mg, 89%) as a
pure (1H NMR, 200 MHz), colorless oil: FTIR (CH2Cl2 cast)
3348 cm-1; 1H NMR (200 MHz, CDCl3) δ 0.95 (s, 3 H), 1.04 (s,
3 H), 1.11 (dd, J ) 7.5, 5.0 Hz, 1 H), 1.26 (d, J ) 8.0 Hz, 1 H),
1.32-1.48 (m, 2 H), 1.56 (dd, J ) 2.0, 1.0 Hz, 3 H), 1.61 (dd,
J ) 1.0, 1.0 Hz, 3 H), 1.66 (ddd, J ) 7.0, 3.5, 2.0 Hz, 1 H),
2.82-3.06 (m, 2 H), 4.56 (br dd, 1 H); 13C NMR (75.5 MHz,
CDCl3) δ 11.21 (q′), 12.69 (q′), 27.61 (q′), 29.13 (q′), 39.89 (t′),
41.85 (s′), 44.42 (d′), 46.19 (t′), 52.95 (d′), 79.75 (d′), 131.07
(s′), 137,70 (s′); exact mass m/ z calcd for C12H20O 180.1514,
found 180.1509. An analytical sample was prepared by
Kugelrohr distillation (90-100 °C, 0.6 mmHg). Anal. Calcd
for C12H20O: C, 79.94; H, 11.18. Found: C, 79.95; H, 11.32.
(1r,3a r,6a r)-(()-1,3a ,4,5,6,6a -Hexa h yd r o-2,3,5,5-tetr a -
m eth yl-1-p en ta len ol (58). Ph3P (611.1 mg, 2.66 mmol) and
chloroacetic acid (251.4 mg, 2.66 mmol) were added succes-
sively to a stirred solution of allylic alcohol 57 (240.1 mg, 1.33
mmol) in dry PhH (10 mL) at room temperature. DEAD (0.42
mL, 2.66 mmol) was added dropwise over ca. 3 min, and
stirring was continued for 3 h. Evaporation of the solution
gave a mixture which contained the desired chloro acetate.
The mixture was dissolved in THF (10 mL plus 5 mL as a
rinse), and this solution was added dropwise over ca. 5 min to
a cooled (0 °C) and stirred suspension of LiAlH4 (303.2 mg,
8.00 mmol) in THF (25 mL). The cooling bath was removed,
and stirring was continued for 30 min. The mixture was then
quenched by successive addition of water (0.3 mL), aqueous
NaOH (3 M, 0.3 mL), and water (0.9 mL). The resulting
mixture was stirred for 20 min and then filtered through a
200 MHz), colorless oil: FTIR (CHCl3 cast) 3310, 2118 cm-1
;
1H NMR (CDCl3, 200 MHz) δ 1.00-1.40 (m, 3 H), 1.40-2.30
(m, 16 H), 5.30-5.50 (m, 1 H); 13C NMR (CDCl3, 50.3 MHz) δ
13.1 (t′), 19.2 (t′), 22.0 (t′), 25.7 (t′), 28.3 (t′), 32.5 (t′), 33.9 (t′),
35.1 (t′), 37.5 (s′), 37.9 (t′), 67.7 (d′), 85.4 (s′), 121.0 (d′), 142.7
(s′); exact mass m/ z calcd for C14H20 188.1565, found 188.1565.
Anal. Calcd for C14H20: C, 89.29; H, 10.71. Found: C, 89.41;
H, 10.99.
(()-4a -(3-Bu t yn yl)oct a h yd r o-3H -n a p h t h [1,8a -b]ox-
ir en e (48). Dimethyldioxirane (0.1 M in acetone, 4.88 mL,
0.488 mmol) was added to a stirred and cooled (0 °C) solution
of olefinic acetylene 45 (91.7 mg, 0.488 mmol) in bench acetone
(15 mL). The cold bath was removed, and after 2 h, additional
dimethyldioxirane was added at room temperature as needed
(TLC control, silica, 1:19 EtOAc-hexane) in order to complete
the reaction. Water (10 mL) was added, and the mixture was
extracted with EtOAc until extraction was complete (TLC
control, silica, 1:19 EtOAc-hexane). The combined organic
extracts were washed with brine, dried (MgSO4), and evapo-
rated. Flash chromatography of the residue over silica gel (1.5
× 17 cm), using 1:19 EtOAc-hexane, gave a 2:1 mixture (1H
NMR) of diastereomeric epoxides 48 (84.0 mg, 84%) as a pure
(1H NMR, 200 MHz), white solid: FTIR (CHCl3 cast) 3307
cm-1; 1H NMR (CDCl3, 200 MHz) δ 0.85-2.40 (m, 38 H), 2.75-
3.00 (m, 2 H); 13C NMR (CDCl3, 50.3 MHz) (two signals overlap
with two other signals) δ 12.5 (t′), 12.6 (t′), 15.1 (t′), 16.0 (t′),
21.0 (t′), 22.0 (t′), 23.5 (t′), 24.0 (t′), 25.8 (t′), 27.8 (t′), 29.4 (t′),
29.8 (t′), 30.4 (t′), 31.8 (t′), 32.4 (t′), 32.8 (t′), 34.4 (t′), 35.9 (t′),
59.7 (d′), 60.0 (d′), 63.8 (s′), 65.2 (s′), 67.7 (d′), 68.1 (d′), 84.9
(s′), 85.4 (s′); exact mass m/ z calcd for C14H20O 204.1514, found
204.1497. Anal. Calcd for C14H20O: C, 82.30; H, 9.87.
Found: C, 82.07; H, 9.92.
(1R*,2S*,6S*)- a n d (1R*,2R*,6S*)-(()-11-Met h ylen e-
tr icyclo[4.4.3.01,6]tr id eca n -2-ol (51) a n d (52). TiCp2Cl (628
mg, 1.49 mmol) in THF (30 mL) was added to a solution of
epoxides 48 (238 mg, 2:1 mixture of diastereomers, 1.17 mmol)
in dry THF (20 mL). After 14 h, aqueous 10% v/v H2SO4 (50
mL) was added, and the aqueous mixture was extracted with
EtOAc until extraction was complete (TLC control, silica, 5%
EtOAc-hexane). The combined organic extracts were washed
successively with saturated aqueous NaHCO3 and water and
then dried (MgSO4) and evaporated. Flash chromatography
of the residue over silica gel (1.5 × 16 cm), using 5% EtOAc-
hexane, gave alcohol 52 (114 mg, 48%) and alcohol 51 (67 mg,
28%) as pure (1H NMR, 200 MHz), colorless solids. Alcohol
52: mp 90-95 °C; FTIR (CH2Cl2 cast) 3464 cm-1 1H NMR
;
(CDCl3, 200 MHz) δ 0.95-2.20 (m, 17 H), 2.25-2.70 (m, 2 H),
3.30-3.60 (s, 1 H), 4.95 (t, J ) 3.0 Hz, 1 H), 5.06 (t, J ) 3.0
Hz, 1H); 13C NMR (CDCl3, 50.3 MHz) δ 17.1 (t′), 21.6 (t′), 22.2
(t′), 29.1 (t′), 29.3 (t′), 30.2 (t′), 30.7 (t′), 33.1 (t′), 35.3 (t′), 43.5
(s′), 51.6 (s′), 75.1 (d′), 106.3 (t′), 157.7 (s′); exact mass m/ z
calcd for C14H22O 206.1671, found 206.1670. A satisfactory
combustion analysis could not be obtained.
Alcohol 51: mp 97-99 °C; FTIR (CH2Cl2 cast) 3463 cm-1
;
1H NMR (CDCl3, 200 MHz) δ 0.70-2.45 (m, 17 H), 2.45-2.65
(m, 2 H), 3.25-3.50 (two broad signals, 1 H), 4.75-4.90 (t, J
) 2.0 Hz, 1 H), 4.95-5.10 (t, J ) 2.0 Hz, 1 H); 13C NMR (CDCl3,
50.3 MHz) δ 19.9 (t′), 20.3 (t′), 21.6 (t′), 21.8 (t′), 27.4 (t′), 27.6
(t′), 28.1 (t′), 31.3 (t′), 36.0 (t′), 44.6 (s′), 53.3 (s′), 70.7 (d′), 105.9
(t′), 156.0 (s′); exact mass m/ z calcd for C14H22O 206.1671,
(39) Stothers, J . B. Carbon-13 NMR Spectroscopy; Academic Press:
New York, 1972, p 167.

Routes to Triquinane and Propellane Systems
J . Org. Chem., Vol. 61, No. 6, 1996 2105
pad (2 × 4 cm) of Celite. The pad was washed with EtOAc,
and the combined filtrates were evaporated. Flash chroma-
tography of the residue over silica gel (2.5 × 15 cm), using
10% EtOAc-hexane, gave allylic alcohol 58 (138.2 mg, 58%)
as a pure (1H NMR, 200 MHz), colorless oil: FTIR (CH2Cl2
cast) 3309, 3295 cm-1; 1H NMR (200 MHz, CDCl3) δ 0.93 (s, 3
H), 0.99 (s, 3 H), 0.99 (d J ) 11.0 Hz, 1 H), 1.05 (dd, J ) 11.0,
10.0 Hz, 1 H), 1.40 (d, J ) 7.5 Hz, 1 H), 1.58 (ddd, J ) 2.0,
1.5, 1.5 Hz, 3 H), 1.62 (ddd, J ) 2.0 Hz, 1 H), 1.64 (ddd, J )
2.0, 1.0, 1.0 Hz, 3 H), 1.78 (ddd, J ) 12.0, 8.5, 2.0 Hz, 1 H),
2.5 (dddd, J ) 12.0, 10.0, 8.0, 2.0 Hz, 1 H), 3.18 (br ddd, J )
8.0, 8.0, 8.0 Hz, 1 H), 4.19 (br d, J ) 8.0 Hz, 1 H); 13C NMR
(75.5 MHz, CDCl3) δ 11.41 (q′), 12.86 (q′), 27.30 (q′), 28.71 (q′),
41.47 (s′), 44.82 (t′), 45.87 (t′), 50.95 (d′), 52.76 (d′), 83.38 (d′),
ture. Stirring was continued for 30 min, and then a solution
of phenyl vinyl sulfoxide (0.53 mL, 4.00 mmol) in THF (2 mL)
and a catalytic amount (1 mg) of KH were added. The mixture
was stirred for 4 h and then quenched by addition of moist
EtOAc followed by water. The layers were separated, and the
aqueous phase was extracted with EtOAc. The combined
organic extracts were washed with brine, dried (MgSO4), and
evaporated. The residue was dissolved in decalin (10 mL), and
NaHCO3 (10 g) was added. The resulting mixture was heated
(150 °C) and stirred for 40 h and then cooled to room
temperature. Water was added, and the aqueous layer was
extracted with EtOAc. The combined organic extracts were
washed with brine, dried (MgSO4), and evaporated. Flash
chromatography of the residue over silica gel (2.5 × 20 cm),
using first hexane and then 10% EtOAc-hexane, gave crude
(TLC, 20% EtOAc-hexane) aldehyde 60, which was used
without further purification.
All of the crude 60 in THF (3 mL plus 2 mL as a rinse) was
added to a stirred and cooled (-78 °C) suspension of LiAlH4
(79.9 mg, 2.00 mmol) in THF (15 mL). The cold bath was
removed, the mixture was allowed to warm to room temper-
ature (30 min), and the reaction was quenched by successive
addition of water (0.08 mL), aqueous NaOH (3 M, 0.08 mL),
and water (0.24 mL). The resulting mixture was stirred for
20 min and then filtered through a pad (3 × 3 cm) of Celite.
The pad was washed with EtOAc, and the combined filtrates
were evaporated. Flash chromatography of the residue over
silica gel (2.5 × 15 cm), using 20% EtOAc-hexane, gave
alcohol 61 (453.6 mg, 73%) as a pure (1H NMR, 200 MHz),
colorless oil, spectroscopically identical with material made
using ethyl vinyl ether.
(1r,3a r,6a r)-(()-1-(2-Br om oeth yl)-1,3a ,4,5,6,6a -h exa h y-
d r o-1,2,5,5-tetr a m eth ylp en ta len e (62). Ph3P (786.9 mg,
3.00 mmol) and CBr4 (995.0 mg, 3.00 mmol) were added
successively to a cooled (0 °C) and stirred solution of alcohol
61 (443.6 mg, 2.13 mmol) in CH2Cl2 (40 mL). The cold bath
was removed, and after 1.5 h, the mixture was filtered through
a pad (3 × 3 cm) of flash chromatography silica gel, using CH2-
Cl2. Evaporation of the filtrate and flash chromatography of
the residue over silica gel (3.5 × 25 cm), using petroleum ether,
gave bromide 62 (551.6 mg, 96%) as a pure (1H NMR, 200
MHz), colorless oil: FTIR (CH2Cl2 cast) 3027, 2952, 2932, 2865,
2857, 1462, 1445, 1381, 1371, 1365 cm-1; 1H NMR (200 MHz,
CDCl3) δ 0.91 (s, 3 H), 0.95 (s, 3 H), 1.02 (s, 3 H), 1.04 (dd, J
) 13.0, 7.0 Hz, 1 H), 1.20-1.38 (m, 2 H), 1.54 (dd, J ) 2.0, 1.0
Hz, 3 H), 1.63 (ddd, J ) 13.0, 9.5, 2.0 Hz, 1 H), 1.81-2.06 (m,
2 H), 2.53 (ddd, J ) 13.0, 8.0, 7.0 Hz, 1 H), 2.90-3.09 (m, 1
H), 3.17-3.46 (m, 2 H), 5.21 (dd, J ) 1.0, 1.0 Hz, 1 H); 13C
NMR (75.5 MHz, CDCl3) δ 12.44 (q′), 20.72 (q′), 27.46 (q′), 29.27
(q′), 29.99 (t′), 40.56 (s′), 42.99 (t′), 45.47 (t′), 46.40 (t′), 47.31
(d′), 51.15 (d′), 51.21 (s′), 130.15 (d′), 141.18 (s′); exact mass
m/ z calcd for C14H23Br 270.0984, found 270.0982. An analyti-
cal sample was prepared by Kugelrohr distillation (82-85 °C,
1.5 mmHg). Anal. Calcd for C14H23Br: C, 61.99; H, 8.55; Br,
29.46. Found C, 61.66; H, 8.83; Br, 29.71.
(1r,3a r,6a r)-(()-1-(3-Bu tyn yl)-1,3a ,4,5,6,6a -h exa h yd r o-
1,2,5,5-tetr a m eth ylp en ta len e (64). n-BuLi (1.6 M in hex-
ane, 3.13 mL, 5.00 mmol) was added dropwise over ca. 5 min
to a cooled (-78 °C) and stirred solution of (trimethylsilyl)-
acetylene (1.41 mL, 10.0 mmol) in THF (15 mL). After a
further 15 min, a solution of bromide 62 (267.0 mg, 0.984
mmol) in THF (5 mL plus 3 mL as a rinse) followed by HMPA
(1 mL) were added. The cold bath was removed, and stirring
was continued for 6 h. Methanolic NaOH (1 M, 15 mL) was
added, and stirring was continued overnight. The mixture was
quenched with water and extracted with hexane. The com-
bined organic extracts were dried (MgSO4) and evaporated.
Flash chromatography of the residue over silica gel (2.5 × 15
cm), using petroleum ether, gave enyne 64 (199.6 mg, 94%)
as a pure (1H NMR, 200 MHz), colorless oil: FTIR (film) 3313,
3027, 2952, 2934, 2867, 2119, 1463, 1447, 1440, 1380, 1374,
1365 cm-1; 1H NMR (200 MHz, CDCl3) δ 0.90 (s, 3 H), 0.93 (s,
3 H), 1.01 (s, 3 H), 1.02 (dd, J ) 13.0, 7.5 Hz, 1 H), 1.17-1.33
(m, 2 H), 1.47-1.74 (m, 3 H), 1.53 (dd, J ) 3.0, 1.5 Hz, 3 H),
1.92 (dd, J ) 2.5, 2.5 Hz, 1 H), 2.01-2.16 (m, 2 H), 2.52 (ddd,
J ) 10.0, 9.0, 8.0 Hz, 1 H), 2.89-3.08 (m, 1 H), 5.21 (dd, J )
130.38 (s′), 140.68 (s′); exact mass m/ z calcd for C12H20
O
180.1514, found 180.1510. An analytical sample was prepared
by crystallization from hexane: mp 38-39 °C. Anal. Calcd
for C12H20O: C, 79.94; H, 11.18. Found: C, 80.10; H, 11.19.
(1r,3a r,6a r)-(()-1,3a ,4,5,6,6a -Hexa h yd r o-1,2,5,5-tetr a -
m eth yl-1-p en ta len eeth a n ol (61). Use of Eth yl Vin yl
Eth er . The yield in this experiment was not always reproduc-
ible. NaOAc (213.3 mg, 2.60 mmol) and Hg(OAc)2 (414.3 mg,
1.30 mmol) were added to a stirred solution of alcohol 58 (234.5
mg, 1.30 mmol) in freshly distilled ethyl vinyl ether (120 mL).
The resulting suspension was refluxed for 72 h and then cooled
to room temperature. Anhydrous K2CO3 was added, and the
excess of ethyl vinyl ether was evaporated. The residue was
taken up in 2:3 CH2Cl2-hexane and filtered through a pad (2
× 4 cm) of Celite. Evaporation of the filtrate and flash
chromatography of the residue over silica gel (2.5 × 20 cm),
using 2% EtOAc-hexane, gave the desired vinyl ether (210.2
mg, 78%) as a colorless oil containing trace impurities (1H
NMR, 200 MHz): FTIR (film) 2951, 2930, 2866, 1644, 1629,
1603, 1463, 1442, 1382, 1366, 1158 cm-1; 1H NMR (200 MHz,
CDCl3) δ 0.94 (s, 3 H), 1.02 (s, 3 H), 1.02 (d, J ) 13.0 Hz, 1 H),
1.14 (dd, J ) 13.0, 10.0 Hz, 1 H), 1.55-1.64 (m, 6 H), 1.64
(ddd, J ) 13.0, 9.0, 2.0 Hz, 1 H), 1.78 (ddd, J ) 13.0, 8.0, 2.0
Hz, 1 H), 2.6 (dddd, J ) 9.0, 9.0, 8.0, 2.0 Hz, 1 H), 3.2 (br ddd,
J ) 8.0, 8.0, 8.0 Hz, 1 H), 4.00 (dd, J ) 7.0, 1.5 Hz, 1 H), 4.23
(dd, J ) 14.0, 1.5 Hz, 1 H), 4.37 (br s, 1 H), 6.41 (ddd, J )
14.0, 7.0, 1.0 Hz, 1 H); 13C NMR (75.5 MHz, CDCl3) δ 11.71
(q′), 12.88 (q′), 27.18 (q′), 28.70 (q′), 41.71 (s′), 45.05 (t′), 45.96
(t′), 46.93 (d′), 52.23 (d′), 87.74 (t′), 93.90 (d′), 127.44 (s′), 142.99
(s′), 150.85 (d′); exact mass m/ z calcd for C14H22O 206.1671,
found 206.1670.
i-Bu3Al (1.0 M in PhMe, 3.9 mL, 3.9 mmol) was added to a
cooled (-78 °C) and stirred solution of the above vinyl ether
(201.0 mg, 0.974 mmol) in CH2Cl2 (15 mL). The cold bath was
removed, and after 1.5 h, the solution was cooled to -78 °C
and quenched by addition of hydrochloric acid (1 M, 2 mL).
The resulting mixture was poured into a separatory funnel
containing 1 M hydrochloric acid (50 mL) and EtOAc (50 mL).
The layers were separated, and the aqueous layer was
extracted with EtOAc. The combined organic extracts were
washed with brine, dried (MgSO4), and evaporated. Flash
chromatography of the residue over silica gel (2.5 × 17 cm),
using 20% EtOAc-hexane, gave alcohol 61 (186.1 mg, 91%)
as a pure (1H NMR, 200 MHz) colorless oil: FTIR (CH2Cl2 cast)
3324 cm-1; 1H NMR (200 MHz, CDCl3) δ 0.91 (s, 3 H), 0.95 (s,
3 H), 1.01 (s, 3 H), 1.04 (dd, J ) 13.0, 7.0 Hz, 1 H), 1.27 (dd,
J ) 2.0, 2.0 Hz, 1 H), 1.32 (d, 1.5 Hz, 1 H), 1.35 (dd, J ) 6.0,
6.0 Hz, 1 H), 1.58 (ddd J ) 1.5, 1.5, 1.5 Hz, 3 H), 1.61-1.71
(m, 3 H), 2.60 (ddd, J ) 11.0, 8.0, 7.0 Hz, 1 H), 2.96-3.14 (m,
1 H), 3.65 (ddd, J ) 7.5, 7.0, 6.0 Hz, 2 H), 5.18 (dd, J ) 1.5,
1.5 Hz, 1 H); 13C NMR (75.5 MHz, CDCl3) δ 12.54 (q′), 21.31
(q′), 27.46 (q′), 29.30 (q′), 40.49 (s′), 43.02 (t′), 44.53 (t′), 46.46
(t′), 47.22 (d′), 48.87 (s′), 51.67 (d′), 60.55 (t′), 129.57 (d′), 143.14
(s′); exact mass m/ z calcd for C14H24O 208.1827, found
208.1829. An analytical sample was prepared by Kugelrohr
distillation (68-70 °C, 1.5 mmHg). Anal. Calcd for C14H24O:
C, 80.71; H, 11.61. Found: C, 80.52; H, 11.68.
(1r,3a r,6a r)-(()-1,3a ,4,5,6,6a -Hexa h yd r o-1,2,5,5-tetr a -
m et h yl-1-p en t a len eet h a n ol (61). Use of P h en yl Vin yl
Su lfoxid e. Alcohol 58 (540.8 mg, 3.00 mmol) in THF (5 mL
plus 1 mL as a rinse) was added to a stirred suspension of
NaH (72.0 mg, 3.00 mmol) in THF (5 mL) at room tempera-

2106 J . Org. Chem., Vol. 61, No. 6, 1996
Clive et al.
1.5, 1.5 Hz, 1 H); 13C NMR (75.5 MHz, CDCl3) δ 12.39 (q′),
13.99 (t′), 20.71 (q′), 27.41 (q′), 29.28 (q′), 40.53 (s′), 40.64 (t′),
43.09 (t′), 46.48 (t′), 47.22 (d′), 49.89 (s′), 50.94 (d′), 67.63 (d′),
85.64 (s′), 129.88 (d′), 141.67 (s′); exact mass m/ z calcd for
C16H24 216.1878, found 216.1870. An analytical sample was
prepared by Kugelrohr distillation (85-90 °C, 1.7 mmHg).
Anal. Calcd for C16H24: C, 88.82; H, 11.18. Found: C, 88.65;
H, 11.12.
continued overnight, and then the mixture was quenched by
addition of 10% H2SO4 (100 mL). The aqueous phase was
extracted with EtOAc, and the combined organic fractions were
washed with saturated aqueous NaHCO3 and brine, dried
(MgSO4), and evaporated. Flash chromatography of the
residue over silica gel (2.5 × 15 cm), using 5% EtOAc-hexane,
gave alcohol 83R (387.6 mg, 82%) as a pure (1H NMR, 200
1
MHz), colorless oil: FTIR (CH2Cl2 cast) 3491 cm-1; H NMR
(200 MHz, CD2Cl2) δ 0.92 (s, 3 H), 0.94 (s, 3 H), 1.00 (s, 3 H),
1.07 (s, 3 H), 1.22-1.66 (m, 7 H), 2.27-2.57 (m, 3 H), 2.78
(dddd J ) 9.0, 7.0, 5.0, 5.0 Hz, 1 H), 3.84 (dd, J ) 7.0, 5.0 Hz,
1 H), 4.74 (ddd, J ) 2.5, 2.5, 1.0 Hz, 1 H), 4.84 (ddd, J ) 2.5,
2.5, 1.0 Hz, 1 H); 13C NMR (75.5 MHz, CD2Cl2) δ 16.90 (q′),
20.02 (q′), 27.42 (q′), 29.37 (q′), 30.66 (t′), 40.04 (t′), 40.28 (t′),
41.64 (s′), 43.96 (t′), 46.64 (d′), 51.78 (s′), 53.17 (d′), 61.14 (s′),
81.41 (d′), 104.77 (t′), 162.40 (s′); exact mass m/ z calcd for
(1R *,2R *,6S *,7R *)-(()-1,4,4,11-Te t r a m e t h yl-8-m e t h -
ylen etr icyclo[5,3,1,02,6]u n d eca n e (66). Bu3SnH (0.11 mL,
0.42 mmol) in PhMe (1 mL) was added to a warmed (80 °C)
and stirred solution of enyne 64 in PhMe (5 mL). AIBN (3.4
mg, 0.021 mmol) was added, and stirring was continued for 3
h. The mixture was then cooled and evaporated. Flash
chromatography of the residue over silica gel (1.5 × 30 cm),
using petroleum ether, gave a mixture (1H NMR, 200 MHz) of
olefin 66 and a byproduct (35.4 mg, ca. 78%, 5:1 in favor of
66).
C16H26
O 234.19836, found 234.19762. Anal. Calcd for
C16H26O: C, 81.99; H, 11.18. Found: C, 81.98; H, 11.37.
(3a r,3b â,6a â,7â,7a r)-(()-De ca h yd r o-3a ,5,5,7a -t e t r a -
m eth yl-1-m eth ylen e-(1H)-cyclopen ta[a ]pen talen -7-ol (83â).
TiCp2Cl (140.9 mg, 0.660 mmol) in THF (6.6 mL) was added
dropwise over ca. 4 min to a stirred solution of epoxide 80â
(75.3 mg, 0.324 mmol) in THF (6 mL). Stirring was continued
for 1.5 h, and then the mixture was quenched by addition of
10% H2SO4 (12 mL). The aqueous phase was extracted with
EtOAc, and the combined organic extracts were washed with
saturated aqueous NaHCO3 and brine, dried (MgSO4), and
evaporated. Flash chromatography of the residue over silica
gel (1.5 × 15 cm), using 5% EtOAc-hexane, gave alcohol 83â
(61.7 mg, 81%) as a pure (1H NMR, 200 MHz), white solid:
FTIR (CH2Cl2 cast) 3441 cm-1; 1H NMR (200 MHz, CD2Cl2) δ
0.90 (s, 3 H), 0.94 (s, 3 H), 1.00 (s, 3 H), 1.07 (s, 3 H), 1.24-
1.56 (m, 5 H), 1.56-1.76 (m, 2 H), 2.04 (dddd, J ) 9.0, 9.0,
8.0, 5.5 Hz, 1 H), 2.21-2.50 (m, 3 H), 3.36 (dd, J ) 9.0, 9.0
Hz, 1 H), 4.80 (ddd, J ) 1.5, 1.0, 1.0 Hz, 1 H), 5.04 (ddd, J )
1.5, 1.0, 1.0 Hz, 1 H); 13C NMR (100.6 MHz, CD2Cl2) δ 20.32
(q′), 20.84 (q′), 27.67 (q′), 29.54 (q′), 33.17 (t′), 41.30 (s′), 41.47
(t′), 43.69 (t′), 45.30 (t′), 50.40 (s′), 50.67 (d′), 52.13 (d′), 59.23
(s′), 87.60 (d′), 106.91 (t′), 158.90 (s′); exact mass m/ z calcd
for C16H26O 234.19836, found 234.19728. An analytical sample
was prepared by crystallization from hexane: mp 50-52 °C.
Anal. Calcd for C16H26O: C, 81.99; H, 11.18. Found: C, 81.88;
H, 11.31.
A sample of 66, containing only trace impurities, was
obtained by repeated flash chromatography, in which late
fractions were discarded. This material had: FTIR (neat film)
3068, 2950, 2930, 2870, 2857, 1648, 1464, 1438, 1381, 1373,
1365 cm-1; 1H NMR (CD2Cl2, 200 MHz) δ 0.75 (d, J ) 7.0 Hz,
3 H), 0.76 (s, 3 H), 0.90-1.24 (m, 3 H), 0.92 (s, 3 H), 1.05 (s, 3
H), 1.29-1.86 (m, 4 H), 1.95-2.10 (m, 2 H), 2.15-2.42 (m, 3
H), 4.45 (dd, J ) 2.5, 2.5 Hz, 1 H), 4.55 (dd, J ) 2.5, 2.5 Hz,
1 H); 13C NMR (CD2Cl2, 75.5 MHz) δ 10.06 (q′), 21.03 (q′), 26.44
(q′), 28.75 (q′), 28.91 (t′), 34.46 (t′), 39.24 (d′), 40.38 (s′), 41.70
(s′), 44.31 (t′), 46.34 (d′), 47.65 (t′), 51.92 (d′), 55.68 (d′), 105.93
(t′), 150.66 (s′); exact mass m/ z calcd for C16H26 218.20344,
found 218.20302.
(1a r,2r,2a r,5a r)- a n d (1a r,2â,2a â,5a â)-(()-2-(3-Bu tyn -
yl)-1a ,2,4,4-t e t r a m e t h yloct a h yd r op e n t a le n o[1,2-b]ox-
ir en e (80r) a n d (80â). NaH2PO4‚H2O (567.8 mg, 4.00 mmol)
and m-CPBA (552.2 mg, 3.20 mmol) were added to a cooled (0
°C) and stirred solution of enyne 64 (347.9 mg, 1.61 mmol) in
CH2Cl2 (60 mL). The mixture was stirred for 3 h, and then
the cold bath was removed. Additional CH2Cl2 (40 mL) was
added, and the organic layer was washed successively with
water, saturated aqueous NaHCO3, and brine, dried (MgSO4),
and evaporated. Flash chromatography of the residue over
silica gel (2.5 × 25 cm), using 5% EtOAc-hexane, gave epoxide
80R (281.6 mg, 75%) as a pure (1H NMR, 200 MHz), colorless
oil and then epoxide 80â (95.2 mg, 25%) as a white solid
containing trace aromatic impurities (1H NMR, 200 MHz). The
stereochemical assignments to 80R and 80â were made on the
basis of NOE measurements on the derived ketone 85â (see
later).
Acetic a cid (3a r,3bâ,6a â,7r,7a r)-(()-Deca h yd r o-3a ,5,5,
7a-tetr am eth yl-1-m eth ylen e-(1H)-cyclopen ta[a ]pen talen -
7-yl Ester (84r). Pyridine (97 µL, 1.2 mmol), Ac2O (0.11 mL,
1.2 mmol), AcCl (85 µL, 1.2 mmol), and DMAP (8.5 mg, 0.070
mmol) were added successively to a stirred solution of alcohol
83R (76.7 mg, 0.328 mmol) in CH2Cl2 (3 mL). The mixture
was stirred and refluxed for 1 h, allowed to cool to room
temperature, diluted with EtOAc (30 mL), washed with water
and brine, dried (MgSO4), and evaporated. Flash chromatog-
raphy of the residue over silica gel (1.5 × 15 cm), using 5%
EtOAc-hexane, gave ester 84R (85.1 mg, 95%) as a pure (1H
Major diastereomer 80R: FTIR (CH2Cl2 cast) 3312, 2953,
2935, 2863, 2119, 1773, 1462, 1442, 1417, 1374, 1366 cm-1
;
1H NMR (200 MHz, CD2Cl2) δ 0.86 (s, 3 H), 0.95 (s, 3 H), 1.02
(s, 3 H), 1.12 (ddd, J ) 11.0, 8.0, 1.5 Hz, 1 H), 1.25 (s, 3 H),
1.29-1.69 (m, 5 H), 1.98 (dd, J ) 2.5, 2.5 Hz, 1 H), 2.03-2.30
(m, 2 H), 2.34 (ddd, J ) 12.0, 9.0, 7.5 Hz, 1 H), 2.55 (dddd, J
) 9.0, 7.5, 7.5, 2.0 Hz, 1 H), 3.09 (d, J ) 2.0 Hz, 1 H); 13C
NMR (75.5 MHz, CD2Cl2) δ 14.12 (t′), 14.22 (q′), 17.23 (q′),
27.45 (q′), 29.09 (q′), 40.19 (t′), 41.44 (t′), 41.76 (s′), 43.33 (d′),
44.80 (s′ and t′ overlapping), 50.42 (d′), 68.16 (d′), 68.86 (d′),
NMR, 200 MHz), colorless oil: FTIR (CH2Cl2 cast) 1740 cm-1
;
1H NMR (200 MHz, CD2Cl2) δ 0.91 (s, 3 H), 0.95 (s, 6 H), 1.05
(s, 3 H), 1.14-1.74 (m, 6 H), 2.06 (s, 3 H), 2.27-2.61 (m, 3 H),
2.83 (dddd, J ) 10.0, 8.0, 8.0, 6.5 Hz, 1 H), 4.84 (dd, J ) 2.5,
2.5 Hz, 1 H), 4.90 (ddd, J ) 2.5, 2.5, 1.0 Hz, 1 H), 4.95 (d, J )
6.5 Hz, 1 H); 13C NMR (75.5 MHz, CD2Cl2) δ 18.20 (q′), 20.13
(q′), 21.18 (q′), 27.71 (q′), 29.55 (q′), 30.72 (t′), 40.12 (t′), 40.23
(t′), 41.93 (s′), 43.55 (t′), 45.85 (d′), 52.00 (s′), 53.71 (d′), 60.71
(s′), 84.37 (d′), 106.16 (t′), 161.26 (s′), 170.73 (s′); exact mass
m/ z calcd for C18H28O2 276.20892, found 276.20853.
73.07 (s′), 85.18 (s′); exact mass m/ z calcd for C16H24
O
232.18270, found 232.18325.
Minor diastereomer 80â: FTIR (CH2Cl2 cast) 3311, 2953,
2933, 2865, 2118, 1772, 1468, 1428, 1419, 1383, 1374, 1366
1
cm-1; H NMR (200 MHz, CD2Cl2) δ 0.89 (s, 3 H), 0.95 (s, 3
H), 1.04 (s, 3 H), 1.06 (dd, J ) 12.0, 12.0 Hz, 1 H), 1.29 (s, 3
H), 1.33-1.77 (m, 5 H), 1.94-2.27 (m, 3 H), 1.95 (dd, J ) 2.5,
2.5 Hz, 1 H), 2.73 (ddd, J ) 12.0, 9.0, 7.5 Hz, 1 H), 3.12 (s, 1
H); 13C NMR (75.5 MHz, CD2Cl2) δ 14.49 (t′), 15.16 (q′), 21.11
(q′), 28.90 (q′), 29.36 (q′), 37.77 (t′), 41.76 (t′), 42.09 (s′), 43.18
(t′), 44.32 (s′), 46.75 (d′), 50.30 (d′), 67.04 (d′), 67.96 (d′), 71.65
(s′), 85.55 (s′); exact mass m/ z calcd for C16H24O 232.18270,
found 232.18129.
Acetic a cid (3a r,3bâ,6a â,7â,7a r)-(()-Deca h yd r o-3a ,5,5,
7a-tetr am eth yl-1-m eth ylen e-(1H)-cyclopen ta[a ]pen talen -
7-yl ester (84â). Pyridine (49 µL, 0.60 mmol), Ac2O (57 µL,
0.60 mmol), AcCl (43 µL, 0.60 mmol), and DMAP (6.1 mg, 0.050
mmol) were added successively to a stirred solution of alcohol
83â (66.5 mg, 0.284 mmol) in CH2Cl2 (3 mL). The mixture
was stirred at room temperature for 1.5 h, diluted with EtOAc
(30 mL), washed with water and brine, dried (MgSO4), and
evaporated. Flash chromatography of the residue over silica
gel (1.5 × 15 cm), using 5% EtOAc-hexane, gave ester 84â
(74.6 mg, 95%) as a pure (1H NMR, 200 MHz), colorless oil:
FTIR (CH2Cl2 cast) 1739 cm-1; 1H NMR (200 MHz, CD2Cl2) δ
(3a r,3b â,6a â,7r,7a r)-(()-De ca h yd r o-3a ,5,5,7a -t e t r a -
m e t h yl-1-m e t h yle n e -(1H )-cyclop e n t a [a ]p e n t a le n -7-ol
(83r). TiCp2Cl (939.6 mg, 4.40 mmol) in THF (44 mL) was
added dropwise over ca. 5 min to a stirred solution of epoxide
80R (466.3 mg, 2.01 mmol) in THF (30 mL). Stirring was

Routes to Triquinane and Propellane Systems
J . Org. Chem., Vol. 61, No. 6, 1996 2107
0.89 (s, 3 H), 0.91 (s, 3 H), 1.03 (s, 3 H), 1.07 (s, 3 H), 1.24-
1.52 (m, 3 H), 1.54 (d, J ) 4.0 Hz, 1 H), 1.61-1.77 (m, 2 H),
1.99 (s, 3 H), 2.24-2.63 (m, 4 H), 4.75-4.85 (m, 2 H), 4.94
(ddd, J ) 2.0, 2.0, 1.0 Hz, 1 H); 13C NMR (75.5 MHz, CD2Cl2)
δ 19.89 (q′), 21.46 (q′), 21.63 (q′), 27.22 (q′), 29.50 (q′), 32.27
(t′), 40.15 (t′), 42.19 (s′), 43.58 (t′), 46.47 (t′), 48.70 (d′), 52.43
(d′), 52.48 (s′), 59.87 (s′), 88.98 (d′), 107.56 (t′), 158.19 (s′),
170.71 (s′); exact mass m/ z calcd for C18H28O2 276.20892, found
276.20806.
(3ar,3bâ,6aâ,7r,7ar)-(()-Decah ydr o-7-h ydr oxy-3a,5,5,7a-
tetr a m eth ylcyclop en ta [e]p en ta len -1-on e (85r). OsO4 (2.5
w/w % in 2-methyl-2-propanol, 1.27 mL, 0.100 mmol) was
added dropwise to a stirred solution of olefinic acetate 84R
(180.3 mg, 0.652 mmol) in acetone (5 mL) and water (0.5 mL).
4-Methylmorpholine N-oxide monohydrate (210.9 mg, 1.80
mmol) was added in one portion, and stirring was continued
for 24 h. The mixture was filtered through a pad (1.5 × 6 cm)
of Celite on top of a pad (1.5 × 7 cm) of flash chromatography
silica gel, using EtOAc. Evaporation of the filtrate and flash
chromatography of the residue over silica gel (1.5 × 20 cm),
using 50% EtOAc-hexane, gave the desired diols (173.1 mg,
85%) as a mixture (TLC) of diastereomers, which was used
without further purification.
K2CO3 (414.6 mg, 3.00 mmol) was added to a stirred solution
of the above diols in MeOH (8 mL), and stirring was continued
for 2 h. The MeOH was evaporated, the flask was flushed with
argon, and CH2Cl2 (8 mL) was added. The mixture was cooled
(0 °C), and Pb(OAc)4 (532.0 mg, 1.20 mmol) was added. The
resulting mixture was stirred for 15 min, the cold bath was
removed, and stirring was continued for 20 min. The mixture
was then filtered through a pad (2 × 3 cm) of flash chroma-
tography silica gel, using EtOAc. Evaporation of the filtrate
and flash chromatography of the residue over silica gel (1.5 ×
20 cm), using 20% EtOAc-hexane, gave ketone 85R (123.6 mg,
80% from 84R) as a pure (1H NMR, 200 MHz), white solid:
FTIR (CH2Cl2 cast) 1728 cm-1; 1H NMR (200 MHz, CD2Cl2) δ
0.93 (s, 3 H), 0.97 (s, 3 H), 0.98 (s, 3 H), 1.08 (s, 3 H), 1.25-
1.85 (m, 7 H), 2.13-2.48 (m, 2 H), 2.51 (ddd, J ) 10.0, 10.0,
9.5 Hz, 1 H), 2.77 (dddd, J ) 10.0, 10.0, 9.5, 7.5 Hz, 1 H), 4.03
(dd, J ) 7.5, 5.0 Hz, 1 H); 13C NMR (75.5 MHz, CD2Cl2) δ 12.07
(q′), 19.89 (q′), 26.99 (q′), 29.20 (q′), 35.51 (t′), 40.16 (t′, t′
overlapping), 41.65 (s′), 43.83 (t′), 47.67 (d′), 49.89 (s′), 53.79
(d′), 65.04 (s′), 77.00 (d′), 222.72 (s′); exact mass m/ z calcd for
C15H24O2 236.17763, found 236.17668. An analytical sample
was prepared by crystallization from hexane: mp 81-82 °C.
Anal. Calcd for C15H24O2: C, 76.23; H, 10.24. Found: C,
76.08; H, 10.52.
(3a r,3bâ,6a â,7â,7a r)-(()-Deca h yd r o-7-h yd r oxy-3a ,5,5,
7a -tetr a m eth ylcyclop en ta [e]p en ta len -1-on e (85â). OsO4
(2.5 w/w % in 2-methyl-2-propanol, 0.70 mL, 0.055 mmol) was
added dropwise to a stirred solution of olefinic acetate 84â
(99.3 mg, 0.359 mmol) in acetone (3 mL) and water (0.25 mL).
4-Methylmorpholine N-oxide monohydrate (117.2 mg, 1.00
mmol) was added in one portion, and stirring was continued
for 24 h. The mixture was filtered through a pad (1.5 × 6 cm)
of Celite on top of a pad (1.5 × 7 cm) of flash chromatography
silica gel, using EtOAc. Evaporation of the filtrate and flash
chromatography of the residue over silica gel (1.5 × 15 cm),
using 50% EtOAc-hexane, gave the desired diols (95.8 mg,
86%) as a mixture (TLC) of diastereomers, which was used
without further purification.
H), 2.11-2.44 (m, 3 H), 2.55 (ddd, J ) 11.0, 11.0, 8.5 Hz, 1 H),
2.88 (d, J ) 8.5 Hz, 1 H), 3.54 (dd, J ) 8.5, 8.5 Hz, 1 H); 13C
NMR (75.5 MHz, CD2Cl2) δ 16.03 (q′), 20.29 (q′), 27.32 (q′),
29.45 (q′), 35.57 (t′), 37.20 (t′), 42.78 (s′), 43.18 (t′), 46.79 (t′),
48.76 (s′), 51.73 (d′), 52.26 (d′), 62.98 (s′), 88.63 (d′), 227.40
(s′); exact mass m/ z calcd for C15H24O2 236.17763, found
236.17678. An analytical sample was prepared by crystal-
lization from hexane: mp 92-93 °C. Anal. Calcd for
C15H24O2: C, 76.23; H, 10.24. Found: C, 75.91; H, 10.04.
Irradiation of the C(7)H signal in the proton NMR spectrum
caused an enhancement of 8% in the signal intensity of one of
the C(6) hydrogens, as expected on the basis of the stereo-
chemistry assigned to 85â.
Th ioca r bon ic Acid O-P h en yl O-[(3a r,3bâ,6a â,7r,7a r)-
(()-Deca h yd r o-3a ,5,5,7a -t et r a m et h yl-1-oxo-(1H )-cyclo-
p en ta [e]p en ta len -7-yl] Ester (86r). DMAP (488.3 mg, 4.00
mmol) and phenyl chlorothionoformate (0.41 mL, 3.0 mmol)
were added successively to a stirred solution of alcohol 85R
(154.2 mg, 0.652 mmol) in MeCN (7 mL). Stirring was
continued for 24 h. The mixture was quenched with water
and extracted with EtOAc. The combined organic extracts
were washed with brine, dried (MgSO4), and evaporated.
Flash chromatography of the residue over silica gel (1.5 × 25
cm), using 10% EtOAc-hexane, gave thionocarbonate 86R
(204.3 mg, 84%) as a pure (1H NMR, 200 MHz), white solid:
FTIR (CH2Cl2 cast) 2953, 2867, 1738, 1591, 1490, 1465, 1457,
1
1408, 1384, 1366, 1244, 1199 cm-1; H NMR (200 MHz, CD2-
Cl2) δ 0.93 (s, 3 H), 0.95 (s, 3 H), 0.99 (s, 3 H), 1.10 (s, 3 H),
1.29-1.53 (m, 4 H), 1.62-1.95 (m, 2 H), 2.23-2.55 (m, 2 H),
2.57 (ddd, J ) 10.0, 10.0, 10.0 Hz, 1 H), 2.97 (dddd, J ) 10.0,
10.0, 9.0, 7.0 Hz, 1 H), 5.59 (d, J ) 7.0 Hz, 1 H), 7.06-7.16
(m, 2 H), 7.24-7.50 (m, 3 H); 13C NMR (75.5 MHz, CD2Cl2) δ
13.01 (q′), 19.73 (q′), 27.11 (q′), 29.21 (q′), 34.65 (t′), 35.15 (t′),
40.38 (t′), 42.32 (s′), 43.00 (t′), 46.69 (d′), 49.67 (s′), 53.49 (d′),
65.16 (s′), 90.12 (d′), 122.24 (d′), 126.92 (d′), 129.94 (d′), 153.74
(s′), 194.83 (s′), 220.67 (s′); exact mass m/ z calcd for C15H23
(M - C7H5O2S) 219.17488, found 219.17448.
O
Th ioca r bon ic Acid O-P h en yl O-[(3a r,3bâ,6a â,7â,7a r)-
(()-Deca h yd r o-3a ,5,5,7a -t et r a m et h yl-1-oxo-(1H )-cyclo-
p en ta [e]p en ta len -7-yl] Ester (86â). DMAP (195.3 mg, 1.60
mmol) and phenyl chlorothionoformate (0.17 mL, 1.2 mmol)
were added successively to a stirred solution of alcohol 85â
(56.7 mg, 0.240 mmol) in MeCN (3 mL). Stirring was
continued for 24 h. The mixture was quenched with water
and extracted with EtOAc. The combined organic extracts
were washed with brine, dried (MgSO4), and evaporated.
Flash chromatography of the residue over silica gel (1.5 × 20
cm), using 10% EtOAc-hexane, gave thionocarbonate 86â
(66.3 mg, 74%) as a pure (1H NMR, 200 MHz), colorless oil:
FTIR (CH2Cl2 cast) 2952, 2864, 1741, 1591, 1490, 1466, 1456,
1406, 1384, 1366, 1292, 1280, 1220, 1200, cm-1; 1H NMR (200
MHz, CD2Cl2) δ 0.92 (s, 3 H), 0.94 (s, 3 H), 1.08 (s, 3 H), 1.11
(s, 3 H), 1.25-1.57 (m, 3 H), 1.67-2.27 (m, 5 H), 2.71-3.00
(m, 2 H), 5.12 (d, J ) 1.5 Hz, 1 H), 7.01-7.13 (m, 2 H), 7.23-
7.47 (m, 3 H); 13C NMR (75.5 MHz, CD2Cl2) δ 17.97 (q′), 18.58
(q′), 26.14 (q′), 29.03 (q′), 35.94 (t′), 37.24 (t′), 41.48 (s′), 44.42
(t′), 48.28 (t′), 51.25 (d′), 53.01 (s′), 55.50 (d′), 63.75 (s′), 100.92
(d′), 122.25 (d′), 126.87 (d′), 129.94 (d′), 153.63 (s′), 193.80 (s′),
218.59 (s′); exact mass m/ z calcd for C15H23O (M - C7H5O2S)
219.17488, found 219.17451.
(3a r,3bâ,6a â,7a r)-(()-Deca h yd r o-3a ,5,5,7a -tetr a -m eth -
ylcyclop en ta [e]p en ta len -1-on e (87) fr om 86r. Et3B (1.0
M in pentane, 0.14 mL, 0.14 mmol) was added dropwise to a
cooled (0 °C) and stirred solution of thionocarbonate 86R (54.2
mg, 0.145 mmol) and Bu3SnH (0.16 mL, 0.58 mmol) in hexane
(3 mL). Air (20 mL) was injected into the flask, and stirring
was continued for 1 h, at which point reaction was still
incomplete (TLC control, silica, 10% EtOAc-hexane). Evapo-
ration of the solvent and flash chromatography of the residue
over silica gel (1.0 × 10 cm), using 5% EtOAc-hexane, gave
mixed fractions of starting material and product. Fractions
containing starting material and/or product were combined
and evaporated. The residue was resubjected to the original
reaction conditions, and after 1 h, all starting material had
been consumed (TLC control, above system). Evaporation of
the solvent and flash chromatography of the residue over
K2CO3 (248.8 mg, 1.80 mmol) was added to a stirred solution
of the above diols in MeOH (5 mL), and stirring was continued
for 2 h. The MeOH was evaporated, the flask was flushed with
argon, and CH2Cl2 (5 mL) was added. The mixture was cooled
(0 °C), and Pb(OAc)4 (310.4 mg, 0.700 mmol) was added. The
resulting mixture was stirred for 15 min, the cold bath was
removed, and stirring was continued for 20 min. The mixture
was then filtered through a pad (2 × 3 cm) of flash chroma-
tography silica gel, using EtOAc. Evaporation of the filtrate
and flash chromatography of the residue over silica gel (1.5 ×
20 cm), using 20% EtOAc-hexane, gave ketone 85â (63.8 mg,
75% from 84â) as a pure (1H NMR, 200 MHz), white solid:
FTIR (CH2Cl2 cast) 1716 cm-1; 1H NMR (200 MHz, CD2Cl2) δ
0.90 (s, 3 H), 0.96 (s, 3 H), 1.00 (s, 3 H), 1.06 (s, 3 H), 1.22 (dd,
J ) 10.0, 7.0 Hz, 1 H), 1.30-1.48 (m, 2 H), 1.59-2.01 (m, 3

2108 J . Org. Chem., Vol. 61, No. 6, 1996
Clive et al.
silica gel (1.0 × 20 cm), using 5% EtOAc-hexane, gave ketone
87 (23.2 mg, 72%) as a pure (1H NMR, 200 MHz), colorless
oil: FTIR (CH2Cl2 cast) 2948, 2865, 1737, 1466, 1451, 1382,
cooled (-20 °C) and stirred solution of ketone 87 (56.4 mg,
0.256 mmol) in MeOH (10 mL). Stirring was continued for
20 min, and then the mixture was quenched with water,
allowed to warm to room temperature, and extracted with
EtOAc. The combined organic extracts were washed with
brine, dried (MgSO4), and evaporated. Flash chromatography
of the residue over silica gel (1.5 × 20 cm), using 20% EtOAc-
hexane, gave alcohol 54 (46.3 mg, 81%) as a pure (1H NMR,
1
1366; H NMR (200 MHz, CD2Cl2) δ 0.90 (s, 3 H), 0.95 (s, 3
H), 1.01 (s, 3 H), 1.06 (s, 3 H), 1.07-1.30 (m, 2 H), 1.41 (br d,
J ) 9.0 Hz, 2 H), 1.60-1.83 (m, 3 H), 1.98-2.73 (m, 5 H); 13
C
NMR (75.5 MHz, CD2Cl2) δ 18.05 (q′), 18.93 (q′), 26.93 (q′),
29.45 (q′), 34.81 (t′), 35.38 (t′), 42.14 (d′), 42.41 (s′), 43.58 (t′),
43.62 (t′), 49.82 (t′), 51.70 (s′), 56.18 (d′), 61.30 (s′), 223.23 (s′);
exact mass m/ z calcd for C15H24O 220.18271, found 220.18280.
(3a r,3bâ,6a â,7a r)-(()-Deca h yd r o-3a ,5,5,7a -tetr a -m eth -
ylcyclop en ta [e]p en ta len -1-on e (87) fr om 86â. Et3B (1.0
M in pentane, 0.18 mL, 0.18 mmol) was added dropwise to a
cooled (0 °C) and stirred solution of thionocarbonate 86â (68.6
mg, 0.184 mmol) and Bu3SnH (0.20 mL, 0.74 mmol) in hexane
(4 mL). Air (20 mL) was injected into the flask, and stirring
was continued for 1 h, at which point reaction was incomplete
(TLC control, silica, 10% EtOAc-hexane). Evaporation of the
solvent and flash chromatography of the residue over silica
gel (1.0 × 10 cm), using 5% EtOAc-hexane, gave mixed
fractions of starting material and product. Fractions contain-
ing starting material and/or product were combined and
evaporated. The residue was resubjected to the original
reaction conditions, and after 1 h, all starting material had
been consumed (TLC control, above system). Evaporation of
the solvent and flash chromatography of the residue over silica
gel (1.0 × 20 cm), using 5% EtOAc-hexane, gave ketone 87
(29.8 mg, 73%) as a pure (1H NMR, 200 MHz), colorless oil,
spectroscopically identical to material obtained in the previous
experiment.
200 MHz), white solid: mp 67-68 °C; exact mass calcd for
1
C
15H26O 222.19836, found 222.19828. The H NMR22 and 13C
NMR21 spectra corresponded with the reported data.
Ack n ow led gm en t. Acknowledgment of financial
support is made to the Natural Sciences and Engineer-
ing Research Council of Canada and to Merck Frosst
(Montreal). S.R.M. holds an NSERC Postgraduate
Scholarship. We thank Dr. M. Postema for advice, Dr.
G. Casty for a generous gift of the titanium reagent, and
Dr. P. L. Wickens for assistance in the preparation of
the manuscript.
Su p p or tin g In for m a tion Ava ila ble: Experimental pro-
cedures for the preparation of compounds 69, 70a ,b, 72a ,b,
73a ,b, 75a ,b, 76a ,b, and 77a ,b and NMR spectra for com-
pounds for which elemental analyses were not obtained (38
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.
(1r,3a â,3b r,6a r,7a â)-(()-De ca h yd r o-3a ,5,5,7a -t e t r a -
m et h yl-(1H )-cyclop en t a [e]p en t a len -1-ol [(()-Cer a t op i-
ca n ol] (54). NaBH4 (29.1 mg, 0.768 mmol) was added to a
J O951930H