Acetylenic silyl ketone as polysynthetic equivalent of useful building blocks in organic synthesis

Article abstract of DOI:10.1016/S0040-4020(01)00578-6

Ethynyl silyl ketone 1 proved to be a very efficient Michael acceptor in carbocupration and metallocupration reactions. In particular, when using carbocuprates, a smooth entry to polyenals can be obtained, while, when using metallocuprates, silyl- and stannylpropenoyl silanes may be obtained, very powerful intermediates in organic synthesis.

Full text of DOI:10.1016/S0040-4020(01)00578-6

TETRAHEDRON
Pergamon
Tetrahedron 57 (2001) 6267±6276
Acetylenic silyl ketone as polysynthetic equivalent of useful
building blocks in organic synthesis
Antonella Capperucci,a,p Alessandro Degl'Innocenti,a,p Paolo Dondoli,a Tiziano Nocentini,a
Gianna Reginatoa and Alfredo Riccib
aDipartimento di Chimica Organica, Centro CNR Composti Eterociclici, Via G. Capponi 9, 50121 Firenze, Italy
bDipartimento di Chimica Organica `A. Mangini' Viale Risorgimento 4, 40136 Bologna, Italy
Received 18 January 2001; revised 25 April 2001; accepted 17 May 2001
AbstractÐEthynyl silyl ketone 1 proved to be a very ef®cient Michael acceptor in carbocupration and metallocupration reactions. In
particular, when using carbocuprates, a smooth entry to polyenals can be obtained, while, when using metallocuprates, silyl- and stannyl-
propenoyl silanes may be obtained, very powerful intermediates in organic synthesis. q 2001 Elsevier Science Ltd. All rights reserved.
Organosilicon compounds have recently gained a predomi-
nant role in the development of novel synthetic method-
ologies for the preparation of various biologically active
compounds, and for their potential in selective organic
synthesis.1 In this context, for instance, allyl,2 vinyl,3 and
dienylsilanes4 have received much attention and their
synthetic utility has been outlined in numerous new
carbon-carbon bond forming reactions.
with several silylated nucleophiles under rather mild and
neutral conditions, prompted us to investigate more closely
the reactions of unsaturated acylsilanes toward different
Michael donors. The aim being to open a new route to
polyfunctionalized molecules, capable of further transfor-
mations toward the synthesis of more complex frameworks,
i.e. useful intermediates in the construction of biologically
active compounds. In particular our attention has been
focused on the reactivity of a particular acylsilane, acetyl-
enic silyl ketone 1, which in our opinion could have
disclosed an even higher degree of reactivity of the parent
ethylenic derivative.
Our interest in organosilicon chemistry has been mainly
focused on the synthesis and reactivity of acylsilanes.5 In
recent years these molecules have been shown to be par-
ticularly versatile compounds, participating in a number of
interesting chemical transformations, some of them particu-
lar of the acylsilane moiety, such as Brook rearrangements,
oxidation to carboxylic acids and ¯uoride promoted con-
version to ketones and aldehydes.6 More recently, they
have been shown to be particularly useful in the preparation
of regio- and stereoisomerically de®ned enol silyl ethers.7
Furthermore the presence of a double bond together with the
acylsilane moiety provides an expansion of acylsilane
synthetic potentialities, and opens the way to the possible
construction of novel and more versatile synthons.8 In this
context, unsaturated acylsilanes9 have recently emerged as
useful intermediates, due to the high reactivity of their vinyl
moiety.10 Our interest in this chemistry led us to evaluate the
potential of these compounds as effective building blocks
for the construction of more complex molecules.
In this paper we report on our recent results on the reactivity
and the synthetic potentialities of acetylenic silyl ketone 1 as
a useful synthetic equivalent. Preliminary accounts of this
reactivity have appeared.13
1. Carbocupration reactions
Recently we disclosed the spontaneous reactivity between
acetylenic silyl ketone 1 with different silylated nucleo-
philes to afford, in mild conditions, a variety of b-func-
tionalized propenoylsilanes (Scheme 1).14 Beside offering
a new methodology for the synthesis of various heterofunc-
tionalized propenoylsilanes, silyl ketone 1 acts as a very
Our recent ®ndings that propenoylsilanes11 and stannanes12
undergo very ef®cient uncatalyzed Michael type reactions
Keywords: acylsilanes; cuprates; Michael reactions; polyenes; polyenals.
Corresponding authors. Tel.: 139-055-2757609; fax: 139-055-2476964;
e-mail: degli@chimorg.uni®.it
p
Scheme 1.
0040±4020/01/$ - see front matter q 2001 Elsevier Science Ltd. All rights reserved.
PII: S0040-4020(01)00578-6

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A. Capperucci et al. / Tetrahedron 57 (2001) 6267±6276
Table 1. Synthesis of b-functionalized a,b-unsaturated acylsilanes and aldehydes
R
Product
Conditions
Yield (%)a
Aldehyde
Yield (%)a
a
b
c
d
Yield are of chromatographically pure compounds.
Ref. 25.
Ref. 26.
Ref. 27.
good Michael acceptor, underlining the very different
chemical behaviour between such compounds and propar-
gyl aldehyde, a compound which is structurally related, and
which can be easily obtained from ketone 1 by simple ¯uo-
ride ion induced desilylation.15
Thus, acetylenic silyl ketone 1 reacts smoothly when treated
with different carbocuprates, leading to the isolation in good
to excellent yield, of the corresponding Michael adducts
3a±f (Table 1).
Both aliphatic, aromatic and unsaturated cuprates react
disclosing a novel access to the class of mono- and poly-
unsaturated acylsilanes.19 All the carbocupration reactions
proved to be completely stereoselective, the E isomers being
the only isolated products. Examples of this reactivity are
summarized in Table 1.
These concepts prompted us to investigate deeper the
chemical behaviour of compound 1 toward nucleophiles
of a different nature such as carbocuprates. Carbocupration
of acetylenic esters has in fact found a wide range of
synthetic applications, although in some cases it is dif®cult
to avoid some isomerized product.16 The reaction of acetyl-
enic ketones and aldehydes is even more sensitive to this
isomerization, although the RCu±BR03 reagent17 seems
somewhat more ef®cient in this respect. In this context,
Normant and Alexakis have presented the carbocupration
of acetylenic acetals as an alternative methodology to
the carbocupration of acetylenic esters, ketones and
aldehydes.18
In this context, of particular synthetic interest it appears the
synthesis of polyunsaturated acylsilanes 3d±f. It is in fact
well established that acylsilanes can be easily converted into
the corresponding aldehydes by simple treatment with
TBAF in THF at room temperature. This chemical
behaviour can be well applied to the newly synthesized
acylsilanes, affording the corresponding aldehydes 4a±c.
Particularly interesting is the desilylation of acylsilanes
3d±f to obtain polyenals 4d±f in good yield (Table 1).
Although some carbocupration reactions on ethylenic
derivatives have been reported,9 no such detailed study
on the acetylenic series has yet been presented in the
literature.
This methodology then discloses a novel access to stereo-
chemically pure polyenals,20 useful intermediates in the

A. Capperucci et al. / Tetrahedron 57 (2001) 6267±6276
6269
an easy access to this class of compounds.21 Upon reaction
of a,b-unsaturated acylsilanes 3b, d, f with ethylidenetri-
phenylphosporane, the corresponding Z-silylated deriva-
tives 5a±c are obtained in satisfactory yield. Again simple
desilylation, with retention of geometry, of compounds
5a±c affords a stereoselective access to polyenes 6a±c
with E geometry of the newly formed terminal double
bond (Table 2).
Table 2. Wittig reaction and desilylation
Moreover, the presence of a vinylsilane moiety in
compounds 5a±c, may provide a further functionalization
site, thus leading to richly functionalized molecules. Then,
in conclusion, dienoylsilanes may afford an easy access both
to Z or E terminal polyenes, in strict relation to the particular
synthetic needs (Table 2).
Compound 5
Yield (%)a,b
Compound 6
Yield (%)a,c
2. Metallocupration reactions
The clean and high yielding reactivity demonstrated by
carbocuprates prompted us to investigate different Michael
donors, whose intrinsic structure could give the starting
molecule a further degree of reactivity.
Metallocupration reactions22 have only recently emerged as
powerful tools in organic synthesis, and they appear to be
the reactions of choice.
Thus, upon reacting silyl ketone 1 with both silyl and
stannyl cuprates, a clean reaction occurred, and the corre-
sponding adducts could be isolated in excellent yields
allowing an easy access to polymetalated molecules,
whose reactivity could possibly be tuned in strict relation
to the nature of both the C±Si and the C±Sn bonds (Scheme
2), for instance, compound 7 may be easily reacted with acyl
a
Yields are of chromatographically pure compounds.
b Reactions run in ether at room temperature for 24 h.
Reactions run in re¯uxing NaOH/TBAF for 12 h.
c
stereoselective synthesis of conjugated polyenes, a class of
compounds which includes natural products such as arachi-
donic acid metabolites and insect pheromones. Results are
summarized in Table 1.
Table 3. Synthesis of polyfunctionalized propenoylsilanes
The importance of this general access to dienoylsilanes is
not limited to the synthesis of polyenals. This is best demon-
strated in their use as intermediates in synthetic organic
chemistry by further transformations. While in fact,
Z-alkenes may be conveniently obtained by reactions of
different aldehydes in the Wittig conditions, the same
cannot be said for E-alkenes when non-stabilized ylides
are used. On the contrary, the use of acylsilanes may offer
Electrophile
Product
Yield (%)
Scheme 2.

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A. Capperucci et al. / Tetrahedron 57 (2001) 6267±6276
Scheme 3.
Scheme 4.
Scheme 5.
chlorides in the presence of AlCl3 to afford the still
unreported conjugated enediones 9a±c. Examples of this
reactivity are summarized in Table 3.
clean reaction occurred, opening an alternative and general
synthetic pathway to dienoylsilanes, as reported in Scheme
3.
The stannyl derivative 8 proved even more interesting from
the synthetic point of view. Upon reaction with different
vinyl iodides under palladium catalyzed conditions, a
This reactivity, as shown in Scheme 4, is not restricted to
simple vinyl iodides, but may be conveniently extended to
more functionalized molecules, such as the NH±BOC
protected derivative 12, thus envisaging a general behaviour
of this class of compounds, that can be easily reacted with 8
to afford compound 13, which can be considered a building
block for more complex biologically active molecules, such
as oxazolomycin.
Table 4. Double functionalization of 1
Furthermore the same compound 13 can be obtained by
reacting 14 with 15, in similar yields by the use of the
classical reactivity of an enonic framework toward stannyl-
ated nucleophiles (Scheme 4).23
Electrophile
Product
Yield (%)
This shows that by using stannylcupration reactions, a ®ne
tuning of the reactional polarity of the C-3 carbon of
the enonic framework can be achieved in a nucleophilic
fashion.
A further probe of this peculiar behaviour is the synthesis of
the dienoylbisacylsilane 1624 that can be conveniently
obtained from the same starting compound, namely acetyl-
enic silyl ketone 1, in which again the reactional polarity of
the C-3 carbon atom may be selected both toward a nucleo-
philic or an electrophilic behaviour in strict relation to the
synthetic needs (Scheme 5).
The versatility of the `stannylcupration' technique is not
limited to the b-functionalization of the ethynyl silyl ketone
1, but the vinylcuprate intermediate may be easily further
functionalized by `in situ' quench with different electro-
philes, thus leading to richly functionalized molecules.
Results are reported in Table 4.
a
2788C to 2108C, 1.5 h, rt.
2788C, 30 min; 208C, 30 min.
b

A. Capperucci et al. / Tetrahedron 57 (2001) 6267±6276
6271
Scheme 6.
Finally, the polyfunctionalized vinylstannanes thus obtained
may be further reacted under Pd catalysis to afford, as in the
case of compound 17b, extremely richly functionalized
molecules, whose interest as building blocks for the syn-
thesis of much more complex molecules is evident
(Scheme 6).
1.68 mmol) and freshly distilled Me2S (2 mL) in anhydrous
diethyl ether (2 mL) is cooled to 08C under argon atmos-
phere, and slowly treated under vigorous stirring with 1.6 M
ethereal solution of MeLi (2.1 mL, 3.36 mmol),28 warmed
to room temperature for 10 min, then cooled to 2788C and
treated dropwise with 1 (0.524 g, 1.68 mmol) in anhydrous
diethyl ether (5 mL) over a period of 10 min. After 40 min
stirring at 2788C the reaction mixture was quenched with
saturated ammonium chloride solution (10 mL), allowed to
reach room temperature and diluted with diethyl ether
(5 mL). The organic layer was separated, washed with
ammonia buffer (10 mL), water (3£10 mL), dried over
Na2SO4 and ®ltered. Concentration of the ®ltrate followed
by chromatographic puri®cation (SiO2, petroleum ether/
diethyl ether) provided 0.51 g (yield 93%) of 3a as a bright
yellow oil, which is stable for several months if stored in the
cold. IR (CCl4, cm21): 3040, 2970, 1605, 1475, 1375, 1300,
1250, 970, 750, 690. 1H NMR (d, CDCl3, 300 MHz): 7.71±
7.32 (m, 15H), 6.68 (dq, 1H, Jˆ17.1, 6.6 Hz), 6.5 (dq, 1H,
Jˆ17.1, 1.3 Hz), 1.8 (dd, 3H, Jˆ6.6, 1.3 Hz). 13C NMR (d,
CDCl3, 75 MHz): 231.3, 145.2, 138.5, 136.7, 135.4, 130.3,
128.3, 18.7. MS (m/z %): 328 (M1, 3), 313 (7), 312 (3), 287
(83), 259 (61), 182 (100), 105 (30), 77 (93), 53 (12). HRMS:
C22H20OSi, calcd 328.1283; found 328.1273.
Thus, in conclusion, acetylenic silyl ketone may effectively
be considered a much more versatile synthetic equivalent
than simply a masked propargyl aldehyde, and propose
compound 1 as real building block for the construction
of polyfunctionalized molecules. Moreover, the
chemistry reported de®nitely shows that compound 1
could be considered as the real synthetic equivalent of the
synthon 19.
3. Experimental
3.1. General
3.1.3. (2E)-Heptenoyltriphenylsilane (3b). A mixture of
CuBr´Me2S (0.065 g, 0.32 mmol) and freshly distilled
Me2S (0.38 mL) in anhydrous ether (1 mL) is cooled to
2788C under argon atmosphere, and slowly treated with
1.6 M solution of n-BuLi (0.4 mL, 0.64 mmol)29, then
warmed to 2508C for 10 min, then cooled again to
2788C and treated with a solution of 1 (100 mg,
0.32 mmol) in anhydrous diethyl ether (1 mL). After
40 min stirring at 2788C the reaction is worked up as
before, to afford, after chromatographic puri®cation (SiO2,
petroleum ether/diethyl ether) 100 mg of 3b as a yellow oil
(89%). IR (CCl4, cm21): 3025, 2950, 1615, 1476, 1370,
1307, 1251, 980, 763, 694. 1H NMR (d, CDCl3,
300 MHz): 7.68±7.33 (m, 15H), 6.67 (dt, 1H, Jˆ16.0,
6.8 Hz), 6.43 (dt, 1H, Jˆ16.0, 1.0 Hz), 2.11±1.96 (m,
2H), 1.42±1.15 (m, 4H), 0.94 (t, 3H Jˆ5.5 Hz). 13C NMR
(d, CDCl3, 50 MHz): 230.8, 151.0, 138.5, 136.8, 135.4,
130.3, 128.3, 28.0, 25.0, 21.0, 17.1. MS (m/z, %): 370
(M1, 2), 327 (31), 313 (70), 287 (56), 259 (73), 182
(100), 105 (38), 77 (89), 53 (18). Anal. calcd for
C25H26OSi: C, 81.03; H, 7.07. Found: C, 80.79; H, 7.21.
NMR spectra were recorded at 200 and 300 MHz on Varian
Gemini 200 and Varian VXR 300 spectrometers, and were
measured as CDCl3 solutions. All solvents were dried with
standard techniques, and distilled before use or stored over
molecular sieves. Column chromatography was carried out
with the ¯ash chromatography technique on silica gel.
Preparative TLC was performed by using silica gel plates.
All the reactions were run under a dry nitrogen or argon
atmosphere. Organic solutions were dried over Na2SO4.
Unless otherwise mentioned, starting materials were
obtained from commercial sources and used without further
puri®cation.
3.1.1. General procedure (compounds 3a±f). A solution
of the appropriate carbocuprate (1 mmol), prepared accord-
ing to the literature, is cooled to 2788C and treated drop-
wise with a solution of 1 (1 mmol) in anhydrous diethyl
ether (3 mL) and stirred at this temperature. After quenching
with a saturated ammonium chloride solution (5 mL), the
mixture is warmed to room temperature and diluted with
diethyl ether (3 mL). The organic layer is separated, washed
with ammonia buffer (5 mL), water (3£5 mL) and dried
over Na2SO4. Evaporation of the solvent affords the crude
product, which can be puri®ed on silica gel (petroleum
ether/diethyl ether).
3.1.4. (2E)-3-Phenyl-propenoyltriphenylsilane (3c).
CuBr´Me2S (0.250 g, 1.22 mmol) and freshly distilled
Me2S (1.5 mL) in anhydrous diethyl ether (1.5 mL) are
cooled to 08C and slowly treated under inert atmosphere
with a 2 M solution of PhLi in cyclohexane/ether (1.2 mL,
2.44 mmol), then allowed to react for 15 min. The mixture is
cooled to 2788C and treated dropwise with a solution of 1
3.1.2. (2E)-Butenoyltriphenylsilane (3a). Following the
general procedure, a mixture of CuBr´Me2S (0.345 g,

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A. Capperucci et al. / Tetrahedron 57 (2001) 6267±6276
(0.381 g, 1.22 mmol) in anhydrous diethyl ether (3.5 mL).
After 40 min at 2788C the mixture is worked-up as
described before to afford, after puri®cation on silica gel
(hexanes/diethyl ether), 433 mg of 3c as a yellow thick oil
(89%). IR (CCl4, cm21): 3039, 1607, 1580, 1470, 1255, 894.
1H NMR (d, CDCl3, 200 MHz): 7.85±7.36 (m, 21H), 6.56
(d, 1H, Jˆ15.8 Hz). 13C NMR (d, CDCl3, 50 MHz):
226.6, 151.4, 135.4, 134.6, 132.7, 129.3, 128.9, 128.5,
127.8, 127.4, 125.7. MS (m/z, %): 390 (M1, 2), 313
(73), 287 (51), 259 (63), 182 (100), 105 (27), 77 (78).
Anal. calcd for C27H22OSi: C, 83.03; H, 5.68. Found: C,
82.81; H, 5.42.
51 (9). Anal. calcd for C25H24OSi: C, 81.47; H, 6.56.
Found: C, 81.00; H, 6.79.
3.1.7. (2E,4Z)-Nona-2,4-dienoyltriphenylsilane (3f). A
solution of (Z-hexenyl)cuprate, prepared according the
reported procedure31 from CuBr´Me2S (130 mg, 0.64
mmol), 1.6 M solution of n-BuLi (0.8 mL, 1.28 mmol)
and acetylene, is cooled to 2788C and treated dropwise
with a solution of 1 (0.156 g, 0.5 mmol) in anhydrous
diethyl ether (2 mL). The orange solution is stirred 1 h at
2788C, then 30 min at 2308C, the reaction mixture was
quenched and worked up in the usual way. Chromatographic
puri®cation (SiO2, petroleum ether/diethyl ether) provided
125 mg (63%) of 3f (dark yellow oil). IR (CCl4, cm21):
3.1.5. (2E)-2,4-Pentadienoyltriphenylsilane (3d).
A
1
mixture of CuBr´Me2S (40 mg, 0.19 mmol) and freshly
distilled Me2S (0.2 mL) in anhydrous ether (0.5 mL) is
cooled to 2788C under argon atmosphere, and treated
with a 2.0 M ethereal solution of vinyllithium (0.2 mL,
0.40 mmol),28 warmed to 2608C for 20 min, then cooled
again to 2788C and treated dropwise with a solution of 1
(50 mg, 0.16 mmol) in anhydrous diethyl ether (1.5 mL).
After 1 h stirring at 2788C the reaction is worked up as
before, to afford, after chromatographic puri®cation (SiO2,
petroleum ether/diethyl ether) 39 mg of 3d (73%) as a pale
brown oil. IR (CCl4): 3031, 1600, 1475, 1255, 751, 693. 1H
NMR (d, CDCl3, 300 MHz): 7.70±7.29 (m, 15H), 6.89 (dd,
1H, Jˆ15.6, 10.8 Hz), 6.52 (bd, 1H, Jˆ15.6 Hz), 6.35
(apparent dt, 1H, Jˆ16.8, 10.8, 9.9 Hz), 5.47 (dd, 1H, Jˆ
9.9, 0.6 Hz), 5.42 (dd, 1H, Jˆ16.8, 0.6 Hz), 13C NMR (d,
CDCl3, 50 MHz): 231.2, 149.8, 138.8, 136.8, 136.0, 135.4,
130.3, 128.2, 118.4, MS (m/z, %): 340 (M1, 26), 313 (3),
259 (100), 182 (95), 155 (45), 105 (71), 53 (65). HRMS:
C23H20OSi calcd 340.1283, found 340.1298.
3030, 2961, 1590, 1475, 1376, 889, 757, 698. H NMR
(d, CDCl3, 300 MHz): 7.69±7.36 (m, 15H), 6.97±6.80
(m, 1H, Jtransˆ16.9 Hz, determined through spin±spin
decoupling experiments), 6.76±6.58 (apt, 1H, Jcisˆ9.0 Hz,
determined through spin±spin decoupling experiments),
6.54±6.41 (m, 1H, Jcisˆ9 Hz), 6.31 (dd, 1H, Jtrans
ˆ
16.9 Hz), 2.20±2.01 (m, 2H), 1.67±1.50 (m, 4H), 1.01±
0.88 (m, 3H). 13C NMR (d, CDCl3, 75 MHz): 235.4,
148.5, 138.1, 136.9, 135.4, 130.3, 128.4, 128.3, 126.3,
30.7, 25.1, 19.4, 17.4. MS (m/z, %): 339 (M1257, 28),
313 (6), 312 (9), 287 (80), 259 (50), 182 (100), 105 (18),
77 (93), 53 (8). HRMS: C27H28OSi calcd 396.1902, found
396.1910.
3.1.8. General procedure (compounds 4a±f). A solution
of triphenylsilylacylsilane 3a±f (0.5 mmol) in THF
(0.5 mL) is cooled to 08C and treated with a solution of
TBAF (0.5 mmol) in THF (1 mL). After stirring 4 h at this
temperature, the mixture is diluted with diethyl ether,
quenched with a saturated solution of NaHCO3 and allowed
to reach room temperature. The organic layer is separated,
washed with water (2£3 mL) and dried over Na2SO4.
Evaporation of the solvent affords the aldehydes 4a±f as
yellow oils, which can be puri®ed on silica gel (petroleum
ether/diethyl ether).
3.1.6. (2E)-5-Methyl-2,4-hexadienoyltriphenylsilane (3e).
2-Methyl-1-propenyllithium is prepared under argon atmos-
phere from a suspension of lithium pieces (0.157 g,
22.6 mmol) in anhydrous diethyl ether (20 mL) by adding
1 mL of a solution of 2-methyl-1-bromo-propene (2.7 g,
20.0 mmol) in anhydrous diethyl ether (5 mL).30 An exo-
termic reaction is observed, and after 30 min the remaining
4 mL of the ethereal solution of the bromine derivative are
added. The mixture is reacted for 3 h and ®ltered to remove
unreacted lithium and lithium bromide. 0.46 mL (0.37
mmol) of this solution are then added to a 2788C cooled
solution of CuBr´Me2S (0.038 g, 0.18 mmol) in anhydrous
ether (0.25 mL) and Me2S (0.2 mL). After 40 min stirring at
2788C the temperature is raised to 2508C for 1 h and
cooled again to 2788C, then treated with 1 (50 mg,
0.16 mmol) in anhydrous diethyl ether (1 mL). After 1 h
stirring at 2788C the reaction is warmed to 2508C for
40 min, then recooled to 2788C and worked up as before,
to afford, after chromatographic puri®cation (SiO2, petro-
leum ether/diethyl ether) 41 mg of 3e (70%, dark yellow
oil). IR (CCl4, cm21): 3030, 1604, 1375, 1250, 969, 843,
Spectroscopical data for aldehydes 4a±c are consistent with
an autentic specimen. Data for compounds 4d±f are identi-
cal to those reported in the literature.25±27
3.1.9.
(2Z,4E)-3-Triphenylsilyl-2,4-nonadiene
(5a).
Typical procedure. A solution of ethylidenetriphenyl-
phosphorane, prepared from ethyltriphenylphosphonium
bromide (102 mg, 0.27 mmol) in dry dietyl ether (1.5 mL)
and 2 M solution of phenyllithium in cyclohexane/ether
(1.3 mL, 0.27 mmol), was treated with a solution of 2(E)-
heptenoyltriphenylsilane 3b (100 mg, 0.27 mmol) in anhy-
drous ether (1 mL). After 24 h stirring at room temperature,
the reaction mixture is diluted with diethyl ether (5 mL), and
poured into 10% HCl solution (10 mL). The organic layer is
separated, washed with 10% HCl (5 mL) and water
(3£10 mL), and dried over Na2SO4. Removal of the solvent
and chromatographic puri®cation (SiO2, petroleum ether/
diethyl ether) affords 85 mg (83%) of 5a as a pale yellow
oil. IR (CCl4, cm21): 3071, 3028, 2975, 2938, 1591, 1475,
1
760. H NMR (d, CDCl3, 300 MHz): 7.71±7.30 (m, 15H),
6.65±6.61 (m, 1H, Jˆ17.1, 10.4, 1.3 Hz determined through
spin±spin decoupling experiments), 6.54±6.41 (m, 1H),
6.31 (dd, 1H, Jˆ17.1, 0.8 Hz), 1.88 (d, 3H, Jˆ1.4 Hz),
1.81 (d, 3H, Jˆ1.1 Hz). 13C NMR (d, CDCl3): 235.4,
148.0, 138.6, 136.9, 135.4, 130.3, 128.5, 128.3, 125.1,
18.9, 18.7. MS (m/z, %): 368 (M1,1), 353 (27), 313 (1),
287 (80), 259 (80), 182 (100), 105 (31), 77 (78), 53 (8),
1
1378, 1309, 1260, 751, 718, 695. H NMR (d, CDCl3,
300 MHz): 7.76±7.30 (m, 15H), 6.28 (dd, 1H, Jˆ16.8,
0.7 Hz), 5.10 (dt, 1H Jˆ16.8, 5.8 Hz), 4.91 (dq, 1H, Jˆ
6.6, 0.7 Hz), 2.11±2.01 (m, 2H), 1.71±1.40 (m, 5H),

A. Capperucci et al. / Tetrahedron 57 (2001) 6267±6276
6273
1.22±0.80 (m, 5H). 13C NMR (d, CDCl3, 75 MHz): 138.7,
136.1, 135.2, 133.4, 130.3, 129.3, 128.2, 127.1, 36.8, 22.4,
18.7, 15.9, 13.7. MS (m/z, %): 382 (M1, 28), 367 (12), 325
(88), 287 (100), 259 (83), 182 (100), 53 (12). Anal. calcd for
C27H30Si: C, 84.76; H, 7.90. Found: C, 84.68; H, 8.03.
200 MHz): 6.35±5.98 (m, 4H), 5.80 (dq, 1H, Jˆ16.2,
7.0 Hz), 5.46 (dt, 1H, Jˆ10.8, 6.9 Hz), 2.16±1.97 (m,
2H), 1.70 (bd, 3H, Jˆ6.9 Hz), 1.37±1.28 (m, 4H), 0.90 (t,
3H, Jˆ7.1 Hz). 13C NMR (d, CDCl3, 50 MHz): 135.8, 129.6,
126.3, 125.7, 124.9, 123.7, 32.9, 31.8, 22.7, 17.7, 13.2. MS
(m/z, %): 150 (M1, 28), 107 (10), 93 (51), 79 (100), 41 (39).
HRMS: C11H18 calcd 150.1409, found 150.1415.
3.1.10. (3E,5Z)-5-Triphenylsilyl-1,3,5-heptatriene (5b).
Yield: 78% (yellow oil). IR (CCl4, cm21): 3090, 3035,
2960, 2930, 2860, 1640, 1620, 1465, 1440, 975, 945, 900.
1H NMR (d, CDCl3, 300 MHz): 7.70±7.30 (m, 15H), 6.55±
6.52 (m, 1H, Jˆ15.0, 11.0 Hz, determined through spin±
spin decoupling experiments), 6.50±6.37 (m, 2H), 5.76 (q,
1H, Jˆ6.9 Hz), 5.48 (m, 1H), 5.31 (m, 1H), 1.82 (d, 3H,
Jˆ6.9 Hz). 13C NMR (d, CDCl3, 75 MHz): 138.8, 136.8,
133.0, 132.3, 130.3, 129.8, 128.0, 127.7, 125.5, 117.0,
18.7. MS (m/z, %): 352 (M1, 33), 337 (81), 325 (80), 287
(100), 259 (80), 180 (99), 53 (12). Anal. calcd for C25H24Si:
C, 85.17; H, 6.86. Found: C, 85.00; H, 7.12.
3.1.15. (E)-3-Trimethylsilyl-propenoyltriphenylsilane (7).
A solution of bis(trimethylsilyl)cuprate, prepared following
standard procedure5a from Me3SiLi and CuCN (0.5 mmol),
is cooled to 2788C and treated with 1 (125 mg, 0.4 mmol).
After 1 h stirring, the solution is warmed to 2238C and
reacted for 30 min. After quenching with saturated ammo-
nium chloride solution (10 mL), the solution is allowed to
reach room temperature. The reaction mixture is diluted
with ether (10 mL) and the organic layer is washed with
ammonia buffer (2£10 mL) and water (2£10 mL) of and
dried over Na2SO4. Removal of the solvent affords the
title compound (134 mg) as a bright yellow oil (87%). IR
(CCl4, cm21): 3064, 3030, 2973, 2931, 1608, 1591, 1475,
1371, 1307, 1255, 1244, 843. 1H NMR (d, CDCl3,
300 MHz): 7.70±7.30 (m, 15H), 6.68 (d, 1H, Jˆ16.5 Hz),
6.38 (d, 1H, Jˆ16.5 Hz), 0.10 (s, 9H). 13C NMR (d, CDCl3,
75 MHz): 231.63, 141.38, 136.73, 135.45, 130.31, 128.46,
128.31, 2.18. MS (m/z, %): 386 (M1, 3), 371 (23), 313 (17),
312 (6), 287 (81), 182 (100), 105 (80), 53 (12). HRMS:
C24H26OSi2 calcd 386.1522, found 386.1531.
3.1.11. (2Z,4E,6Z)-3-Triphenylsilyl-2,4,6-undecatriene (5c).
Yield: 74% (orange±yellow oil). IR (CCl4, cm21): 3073,
3027, 2978, 2936, 1589, 1473, 1377, 1308, 1261, 753,
1
723, 695. H NMR (d, CDCl3, 300 MHz): 7.70±7.30 (m,
15H), 6.12±5.85 (m, 2H), 5.81 (dt, 1H, Jˆ9.0, 7.2 Hz), 5.21
(dd, 1H, Jˆ16.9, 0.8 Hz), 4.97 (bq 1H, Jˆ6.7 Hz), 2.10±
2.02 (m, 2H), 1.70±1.41 (m, 5H), 1.21±0.85 (m, 5H). 13C
NMR (d, CDCl3, 50 MHz): 137.7, 136.5, 136.1, 135.1,
133.3, 131.2, 129.3, 128.7, 128.1, 127.1, 37.0, 22.5, 18.7,
15.0, 13.2. MS (m/z, %): 408 (M1, 3), 393 (21), 351 (93),
287 (100), 182 (93), 77 (91), 53 (18). Anal. calcd for
C29H32Si: C, 70.49; H, 15.71. Found: C, 70.55; H, 15.68.
3.1.16. (E)-3-Tributylstannyl-propenoyltriphenylsilane
(8). To a solution of the stannylcuprate, prepared from
CuCN (0.067 g, 0.75 mmol), 1.6 M solution of n-BuLi in
hexane (0.63 mL, 1.5 mmol) and Bu3SnH (0.4 mL) in
anhydrous THF (2 mL), cooled to 2788C, propinoyltri-
phenylsilane 1 (234 mg, 0.75 mmol) is added dropwise.
After 30 min stirring at 2788C the reaction mixture is
quenched with saturated NH4Cl solution (5 mL). Usual
workup procedure affords a bright yellow oil puri®ed by
¯ash chromatography: hexabutyldistannane is eluted with
petroleum ether and the pure product is recovered by elution
with diethyl ether/petroleum ether 1:1. The product must be
stored in the cold and protected from light. Yield: 86%
(389 mg). IR (CCl4, cm21): 3036, 1598, 1310, 969, 753,
3.1.12. (2E,4E)-2,4-Nonadiene (6a). Typical procedure. A
solution of (2Z,4E)-3-triphenylsilyl-2,4-nonadiene 5a
(60 mg, 0.16 mmol) in THF (2 mL) is treated with a
NaOH/TBAF solution (10 mg of NaOH and 76 mg of
TBAF in THF/H2O, 0.24 mmol) and re¯uxed for 12 h.
The resulting mixture is diluted with Et2O (5 mL), washed
with a saturated solution of NH4Cl and water. After drying
over Na2SO4 and removing of the solvent, the crude product
is puri®ed on silica gel to afford 18 mg of pure diene 6a
(91%) as a yellow oil. IR (CCl4, cm21): 3020, 1640, 1625,
1465, 990, 965. 1H NMR (d, CDCl3, 200 MHz): 6.30±6.11
(m, 1H), 5.91±5.62 (m, 3H), 2.21±2.09 (m, 2H), 1.68 (bd,
3H, Jˆ6.7 Hz), 1.42±1.30 (m, 4H), 0.91 (t, 3H, Jˆ6.9 Hz).
13C NMR (d, CDCl3, 50 MHz): 136.9, 133.2, 129.8, 129.1,
33.3, 30.2, 22.9, 17.8, 14.0. MS (m/z, %): 124 (M1, 10), 109
(13), 82 (87), 81 (100), 95 (13), 67 (21). HRMS: C9H16 calcd
124.1252, found 124.1266.
1
697. H NMR (d, CDCl3, 300 MHz): 7.70±7.33 (m, 15H),
6.88 (d, 1H, Jˆ16.8 Hz), 6.56 (d, 1H, Jˆ16.8 Hz), 1.58±
1.26 (m, 12H), 1.00±0.81 (m, 15H). 13C NMR (d, CDCl3,
50 MHz): 233.4, 141.2, 140.5, 136.9, 135.4, 130.3, 128.4,
25.1, 24.2, 13.0, 9.88. MS(m/z, %): 604 (M1, 3), 589 (21),
547 (78), 490 (23), 313 (2), 291 (17), 287 (81), 182 (100), 57
(23). HRMS: C33H44OSiSn calcd 602.2183, found 602.2193.
3.1.13. (3E,5E)-1,3,5-Heptatriene (6b). Yield: 82% (dark
yellow oil). IR (CCl4, cm21): 3010, 1628, 1610, 1458, 1430,
1010, 975, 935, 890. 1H NMR (d, CDCl3, 200 MHz): 6.61±
6.57 (m, 3H), 6.19 (bdd, 1H, Jˆ15.8, 10.3 Hz), 5.79 (dq,
1H, Jˆ15.8, 6.9 Hz), 5.25±5.14 (m, 2H), 1.69 (bq, 3H,
Jˆ6.9 Hz). 13C NMR (d, CDCl3, 50 MHz): 136.4, 132.0,
130.1, 127.8, 125.3, 116.7, 17.5. MS (m/z, %): 94 (M1,
12), 67 (31), 41 (100). HRMS: C7H10 calcd 94.0782,
found 94.0775.
3.1.17. (E)-3-Benzoyl-propenoyltriphenylsilane (9a).
Typical procedure.
A solution of PhCOCl (78 mg,
0.61 mmol) in dry CH2Cl2 (1 mL) is added under inert
atmosphere to a dispersion of dry AlCl3 (160 mg,
1.2 mmol) in anhydrous CH2Cl2 (1 mL) at 08C. After
10 min stirring the clear obtained solution is transferred
via a syringe in a ¯ask containing a solution of 7 (134 mg,
0.35 mmol) in dry CH2Cl2 (1.5 mL). After 3 h stirring at
08C, usual quench with NH4Cl and workup with ether
follow. Filtration on ¯orisil affords the title compound
(70 mg, 48%) as a yellow oil. IR (CCl4, cm21): 3077,
3028, 2974, 2935, 1635, 1590, 1472, 1371, 1258, 972,
3.1.14. (2E,4E,6Z)-2,4,6-Undecatriene (6c). Yield: 89%
(orange oil). IR (CCl4, cm21): 3051, 1630, 1620, 1461,
1005, 970, 960, 940, 880, 835. 1H NMR (d, CDCl3,

6274
A. Capperucci et al. / Tetrahedron 57 (2001) 6267±6276
1
777, 699. H NMR (d, CDCl3, 300 MHz): 7.81 (d, 1H,
Jˆ16.9 Hz), 7.77±7.31 (m, 20H), 6.87 (d, 1H, Jˆ
16.9 Hz). 13C NMR (d, CDCl3, 50 MHz): 236.7, 200.1,
148.7, 141.9, 140.7, 135.7, 134.6, 130.2, 129.7, 129.2,
128.8, 121.2. MS (m/z, %): 418 (1), 406 (17), 403 (12),
390 (22), 341 (6), 287 (63), 259 (70), 182 (100), 159 (71),
77 (88), 53 (8). Anal. calcd for C28H22O2Si: C, 80.35; H,
5.30. Found: C, 80.06; H, 5.54.
1608, 1463, 1310, 970. 1H NMR (d, CDCl3, 200 MHz): 6.57
(dt, 1H, Jˆ16.5, 5.8 Hz), 6.23 (dt, 1H, Jˆ16.5, 1.0 Hz), 4.68
(bs, 1H), 3.66 (bdd, 2H, Jˆ5.8, 1.0 Hz), 1.40 (s, 9H). 13C
NMR (d, CDCl3): 155.4, 144.2, 80.0, 77.7, 43.3, 28.3. MS
(m/z, %): 283 (M1, 3), 157 (10), 156 (8), 127 (34), 101
(100), 85 (43), 73 (88), 57 (98). HRMS: C8H14INO2 calcd
283.0069, found 283.0050.
(E)-N-Boc-3-iodo-2-propene-1-amine 12 (45 mg, 0.16 mmol)
and acylsilane 8 (96 mg, 0.16 mmol) are dissolved in anhy-
drous DMF (1.5 mL), together with PdCl2(CH3CN)2 (2 mg,
7.7£1023 mmol) and allowed to react in the dark for 12 h at
room temperature. The reaction mixture is then diluted with
ether (10 mL) and washed with water (5£10 mL). The
organic layer is dried over Na2SO4 and, after removal of
the solvent, 62 mg (yield 83%) of pure 13 (yellow thick
oil) are recovered by ®ltration on ¯orisil with ether, after
elution of the stannylated by-products with hexane. IR (neat,
cm21): 3363, 3040, 2981, 1702, 1610, 1510, 1460, 1360,
3.1.18. (E)-3-(p-Toluoyl)-propenoyltriphenylsilane (9b).
Yield: 51% (yellow oil). IR (CCl4, cm21): 3053, 2991,
1646, 1640, 1633, 1595, 1460, 1352, 1251, 851. H NMR
1
(d, CDCl3, 200 MHz): 7.88 (d, 1H, Jˆ16.3 Hz), 7.70±7.39
(m, 19H), 7.02 (d, 1H, Jˆ16.3 Hz), 2.25 (s, 3H). 13C NMR
(d, CDCl3, 50 MHz): 235.9, 193.5, 149.1, 143.0, 141.5,
135.8, 135.1, 134.9, 129.3, 129.0, 128.8, 127.6, 21.4. MS
(m/z, %): 432 (5), 416 (11), 341 (28), 287 (59), 259 (78), 119
(100), 91 (85), 65 (8). Anal. calcd for C29H24O2Si: C, 80.52;
H, 5.59. Found: C, 80.37; H, 5.71.
1
990. H NMR (d, CDCl3, 300 MHz): 7.71±7.30 (m, 15H),
3.1.19.
(E)-3-Acetyl-propenoyltriphenylsilane
(9c).
6.55 (dd, 1H, Jˆ14.3, 10.0 Hz), 6.51 (d, 1H, Jˆ14.1 Hz),
6.38 (ddt, 1H, Jˆ15.2, 10.0, 5.0 Hz), 5.86 (dt, 1H, Jˆ15.1,
6.5 Hz), 5.21 (bs, 1H), 3.90 (apt, 2H, Jˆ5.0 Hz), 1.45 (s,
9H). 13C NMR (d, CDCl3): 231.4, 155.4, 148.5, 136.7,
134.5, 132.3, 129.6, 128.5, 128.3, 127.4, 77.6, 42.3, 28.8.
MS (m/z, %): 412 (M1257, 4), 368 (21), 313 (7), 182 (100),
77 (91). Anal. calcd for C29H31NO3Si: C, 74.16; H, 5.92; N,
2.98. Found: C, 74.32; H, 6.27; N, 2.80.
Yield: 45% (yellow oil). IR (CCl4, cm21): 3022, 2987,
1661, 1650, 1637, 1596, 1467, 1348, 1250, 852. H NMR
1
(d, CDCl3, 300 MHz): 7.73±7.32 (m, 15H), 7.21 (d, 1H,
Jˆ16.4 Hz), 6.87 (d, 1H, Jˆ16.4 Hz), 2.31 (bs, 3H). 13C
NMR (d, CDCl3, 50 MHz): 231.8, 193.3, 149.8, 144.5,
136.1, 134.4, 130.1, 128.9, 25.6. MS (m/z, %): 356 (18),
341 (51), 313 (59), 259 (19), 97 (55), 43 (100). Anal. calcd
for C23H20O2Si: C, 77.49; H, 5.65. Found: C, 77.18; H,
6.00.
Procedure 2. Preparation of (E)-3-iodopropenoyltriphenyl-
silane (14). Propynoylsilane 1 (31 mg, 0.1 mmol) is dis-
solved in CHCl3 (1 mL) and iodotrimethylsilane (22 mg,
0.11 mmol) is added. After 30 min stirring at room tempera-
ture the solvent is evaporated and the usual puri®cation by
®ltration with hexane and ether follows, to afford 40 mg of
14 (yield 92%) as an orange oil to be stored in the dark. IR
(CCl4, cm21): 3079, 3031, 1599, 1475, 1309, 1254, 968,
3.1.20. (2E,4E)-5-Phenyl-2,4-pentadienoyltriphenylsilane
(11). Compound 8 (121 mg, 0.2 mmol) and 1-(E)-iodo-2-
phenylethylene 10 (46 mg, 0.2 mmol),32 are mixed under
an inert atmosphere and then dissolved in anhydrous DMF
(0.5 mL). Then PdCl2(CH3CN)2 (2 mg, 7.7£1023 mmol) are
added and the mixture is stirred 24 h in the dark at room
temperature, then diluted with diethyl ether (10 mL) and
washed with water (2£10 mL). The organic layer is dried
over Na2SO4 and, after removal of the solvent, 50 mg
(0.12 mmol, yield 60%) of the pure product are obtained
by ¯ash chromatography (diethyl ether/petroleum ether) as
a yellow thick oil. IR (CCl4, cm21): 3095, 3038, 1607, 1475,
1
751, 693. H NMR (d, CDCl3, 200 MHz): 7.70±7.36 (m,
16H), 7.21 (d, 1H, Jˆ18 Hz). 13C NMR (d, CDCl3): 231.0,
140.5, 136.7, 135.4, 132.4, 130.3, 89.4. MS (m/z, %): 440
(M1,18), 313 (6), 312 (7), 311 (18), 254 (9), 182 (100), 77
(91). Anal. calcd for C21H17IOSi: C, 57.28; H, 3.89. Found:
C, 57.00; H, 4.07.
1
1311, 1255, 968, 751, 730, 710, 693. H NMR (d, CDCl3,
300 MHz): 7.76±7.30 (m, 20H), 6.87 (ddd, 1H, Jˆ16.9,
10.3, 0.8 Hz), 6.76 (ddd, 1H, Jˆ15.3, 10.3, 0.9 Hz), 6.58
(bdd, 1H, Jˆ15.3, 0.8 Hz), 6.31 (bdd, 1H, Jˆ16.9, 0.9 Hz).
13C NMR (d, CDCl3, 50 MHz): 230.7, 141.3, 140.5, 136.7,
135.4, 130.3, 129.3, 128.4, 128.2, 125.8, 125.1, 120.1,
119.7, 118.6. MS (m/z, %): 416 (M1, 8), 339 (71), 313
(7), 287 (80), 182 (100), 77 (91), 53 (1). Anal. calcd for
C29H24OSi: C, 83.61; H, 5.81. Found: C, 83.40; H, 6.03.
(E)-3-Iodopropenoyltriphenylsilane 14 (40 mg, 0.10 mmol)
and 15 (45 mg, 0.10 mmol)33 are dissolved in dry DMF
(1.5 mL), together with PdCl2(CH3CN)2 (2 mg, 7.7£
1023 mmol). The procedure is the same as Procedure 1
and affords 41 mg of 13 (yield 86%).
3.1.22. 1,6-Bis-(triphenylsilyl)-(2E, 4E)-hexadien-1,6-
dione (16). Following the previous procedure, (E)-3-iodo-
propenoyltriphenylsilane 14 (40 mg, 0.1 mmol) and (E)-3-
tributylstannylpropenoyltriphenylsilane 8 (55 mg, 0.1 mmol)
afford the title compound 16 in 75% yield (47 mg) as an
orange thick oil. IR (CCl4, cm21): 3072, 3032, 1583, 751,
3.1.21. (2E,4E)-6-t-Butoxycarbonylamino-2,4-hexadien-
oyltriphenylsilane (13). Procedure 1. Preparation of(E)-
N-Boc-3-iodo-2-propen-1-amine (12). A solution of I2
(101 mg, 0.40 mmol) in CH2Cl2 (2 mL) is added to (E)-N-
Boc-3-tributylstannyl-2-propen-1-amine 15 (171 mg, 0.38
mmol)33 and the mixture is allowed to react for 8 h at
room temperature. Removal of the solvent, followed by
®ltration on ¯orisil with hexane and then with ether, affords
105 mg (yield 98%) of 12 as a colorless liquid to be stored in
the dark. IR (CCl4, cm21): 3352, 3040, 2957, 2926, 1702,
1
691. H NMR (d, CDCl3, 200 MHz): 7.69±7.28 (m, 30H),
6.89 (d, 2H, Jˆ16.1 Hz), 6.44 (d, 2H, Jˆ16.1 Hz). 13C
NMR (d, CDCl3, 50 MHz): 234.7, 142.9, 135.5, 133.3,
130.3, 129.0, 128.8. MS (m/z, %): 626 (M1, 5), 549 (3),
368 (85), 312 (12), 287 (85), 259 (63), 182 (100), 105
(32), 77 (91). Anal. calcd for C42H34O2Si2: C, 80.47; H,
5.47. Found: C, 80.19; H, 5.61.

A. Capperucci et al. / Tetrahedron 57 (2001) 6267±6276
6275
3.1.23. (E)-2-Carbethoxymethyl-3-tributylstannylpro-
penoyltriphenylsilane (17a). To a solution of the stannyl
derivative 8, prepared with the usual procedure from 1
(69 mg, 0.22 mmol), a large excess of solid CO2 is added
at 2788C. The reaction mixture is allowed to reach very
slowly (about 2 h) 2108C, then is quenched with dimethyl-
sulfate (28 mg, 0.22 mmol) and allowed to react for 1.5 h at
room temperature. The reaction mixture is diluted with ether
(10 mL) and then poured into ammonia buffer (10 mL). The
organic layer is washed with ammonia buffer (3£10 mL),
saturated NH4Cl solution (2£10 mL) and water (3£10 mL).
The organic layer is dried and, after removal of the solvent,
the crude product is puri®ed by ®ltration with hexane on
¯orisil, recovering the pure product 17a with ether in 83%
yield (121 mg) as an orange±yellow oil. IR (CCl4, cm21):
3078, 3033, 2972, 2936, 1717, 1601, 1473, 1378, 1310,
1255, 969, 752, 695. 1H NMR (d, CDCl3, 200 MHz):
7.70±7.30 (m, 15H), 6.83 (s, 1H), 4.01 (s, 3H), 1.59±1.24
(m, 12H), 1.20±0.80 (m, 15H). 13C NMR (d, CDCl3): 227.9,
166.5, 144.3, 142.0, 137.0, 135.4, 130.3, 128.4, 51.5, 25.1,
24.2, 13.0, 9.9. MS (m/z, %): 631 (M12OMe, 13), 605 (71),
548 (12), 291 (31), 182 (100), 77 (91), 57 (81). Anal. calcd for
C35H46O3SiSn: C, 63.55; H, 7.01. Found: C, 63.19; H, 7.30.
tributylstannylpropenoyltriphenylsilane 17b (95 mg, 0.15
mmol) and 1-(E)-iodo-2-phenylethylene 10 (34 mg, 0.15
mmol) afford the title compound (56 mg, 0.12 mmol) as a
pale yellow oil in 81% yield. IR (neat, cm21): 3071, 3030,
2971, 2939, 1630, 1591, 1473, 1371, 1251, 968, 751, 693.
1H NMR (d, CDCl3, 300 MHz): 7.72±7.33 (m, 21H), 6.85
(dd, 1H, Jˆ16.9, 12.1 Hz), 6.76 (d, 1H, Jˆ16.9 Hz), 2.31 (s,
3H). 13C NMR (d, CDCl3): 232.8, 196.9, 147.2, 142.3,
137.0, 135.7, 131.4, 130.2, 129.1, 128.8, 128.2, 127.5,
126.0, 25.6. MS (m/z, %): 415 (M1243, 21), 381 (81),
342 (12), 287 (71), 259 (71), 199 (71), 182 (100), 105
(30), 77 (92), 53 (10). Anal. calcd for C31H26O2Si: C,
81.18; H, 5.71. Found: C, 81.00; H, 5.83.
Acknowledgements
The authors gratefully acknowledge Mrs Brunella Innocenti
for carrying out elemental analyses.
References
1. (a) Colvin, E. W. Silicon in Organic Synthesis, Academic
Press: London, 1988. (b) Colvin, E. W. Silicon in Organic
Synthesis, Butterworths: London, 1981. (c) Weber, W. P.
Silicon Reagents for Organic Synthesis, Springer Verlag:
Berlin, 1983. (d) Fleming, I. Chem. Soc. Rev. 1981, 10, 83.
(e) Chan, T. H.; Fleming, I. Synthesis 1979, 761. (f) Colvin,
E. W. Comprehensive Organometallic Chemistry II;
McKillop, A., Ed.; Pergamon: Oxford, 1995; Vol. 11 (Chapter
7). (g) Qi, H.; Curran, D. P. Comprehensive Organic
Functional Group Transformations; Katritzky, A. R., Meth-
Cohn, O., Rees, C. W., Eds.; Elsevier: Oxford, 1995; Vol. 5
(Chapter 9).
3.1.24. (E)-2-Acetyl-3-tributylstannylpropenoyltriphenyl-
silane (17b). To a solution of the stannyl derivative 8,
prepared from 1 (69 mg, 0.22 mmol), acetyl chloride
(17 mg, 0.22 mmol) is added at 2788C and stirred for
30 min. The reaction mixture is allowed to reach slowly
(about 2 h) room temperature and, after 30 min stirring at
208C, usual workup procedure follows. 96.4 mg of 17b
(68%) are obtained as a yellow oil. IR (CCl4, cm21):
3079, 3031, 2972, 2936, 1630, 1597, 1475, 1375, 1309,
1253, 968, 751, 693. 1H NMR (d, CDCl3, 200 MHz):
7.70±7.34 (m, 15H), 6.95 (s, 1H), 2.31 (s, 3H), 1.60±1.25
(m, 12H), 1.20±0.86 (m, 15H). 13C NMR (d, CDCl3): 228.7,
197.5, 147.1, 141.9, 137.6, 135.1, 128.6, 128.3, 25.7, 25.1,
24.2, 13.2, 9.8. MS (m/z, %): 646 (M1, 2), 603 (13), 589
(91), 532 (11), 291 (18), 276 (61), 182 (100). Anal. calcd for
C35H46O2SiSn: C, 65.12; H, 7.18. Found: C, 64.90; H, 7.25.
2. Fleming, I.; Dunogues, J. Org. React. 1989, 54, 268.
3. Hatanaka, Y.; Miyama, T. J. Org. Chem. 1989, 54, 268.
4. (a) Babudri, F.; Fiandanese, V.; Marchese, G.; Naso, F.
J. Chem. Soc., Chem. Commun. 1991, 237. (b) Babudri, F.;
Fiandanese, V.; Hassan, O.; Punzi, A.; Naso, F. Tetrahedron
1998, 54, 4327 (and references cited therein).
3.1.25. (E)-[2-(1-Propenyl)]-3-tributylstannylpropenoyl-
triphenylsilane (17c). A solution of the stannylderivative
8, prepared from 1 (69 mg, 0.22 mmol), is treated at 2788C
with allylbromide (26 mg, 0.22 mmol) and stirred for
30 min. The solution is allowed to reach slowly room
temperature and after 30 min the usual work-up procedure
affords the crude product, which isomerizes to the conju-
gated diene 17c upon standing at room temperature (24 h).
Usual puri®cation gives 72 mg of pure 17c (51%) as a
yellow oil. IR (CCl4, cm21): 3049, 3026, 2985, 2930,
5. (a) Ricci, A.; Degl'Innocenti, A.; Faggi, C.; Capperucci, A.;
Seconi, G.; Dembech, P. J. Org. Chem. 1988, 53, 3612.
(b) Ricci, A.; Degl'Innocenti, A.; Capperucci, A.; Reginato,
G. J. Org. Chem. 1989, 54, 19. (c) Degl'Innocenti, A.; Ulivi,
P.; Capperucci, A.; Reginato, G.; Mordini, A.; Ricci, A.
Synlett 1992, 883. (d) Bestmann, H. J.; Haas, W.; Witzgall,
K.; Ricci, A.; Lazzari, D.; Degl'Innocenti, A.; Seconi, G.;
Dembech, P. Liebigs Ann. 1995, 415. (e) Bonini, B. F.;
Comes-Franchini, M.; Fochi, M.; Laboroi, F.; Mazzanti, G.;
Ricci, A.; Varchi, G. J. Org. Chem. 1999, 64, 8008. (f) Bonini,
B. F.; Comes-Franchini, M.; Fochi, M.; Mazzanti, G.; Ricci,
A. Synlett 1999, 486. (g) Bonini, B. F.; Comes-Franchini, M.;
Fochi, M.; Gawronski, J.; Mazzanti, G.; Ricci, A.; Varchi, G.
Eur. J. Org. Chem. 1999, 437. (h) Bonini, B. F.; Comes-
Franchini, M.; Fochi, M.; Mazzanti, G.; Ricci, A.; Varchi,
G. Synlett 2000, 1688.
1
1645, 1611, 1473, 1371, 1255, 970, 853. H NMR (d,
CDCl3, 200 MHz): 7.69±7.31 (m, 15H), 6.41 (bd, 1H,
Jˆ15.9 Hz), 6.20 (s, 1H), 5.68 (dq, 1H, Jˆ15.9, 7.2 Hz),
1.70 (bd, 3H, Jˆ7.2 Hz), 1.51±1.28 (m, 12H), 1.25±0.82
(m, 15H). 13C NMR (d, CDCl3): 228.0, 148.2, 139.0, 136.9,
135.2, 130.3, 129.1, 128.2, 126.4, 25.9, 25.3, 17.4, 13.1, 9.7.
MS (m/z, %): 629 (M1215, 11), 603 (51), 385 (100) 353
(35). Anal. calcd for C36H48OSiSn: C, 67.19; H, 7.52.
Found: C, 66.85; H, 7.72.
6. (a) Ricci, A.; Degl'Innocenti, A. Synthesis 1989, 647.
(b) Bulman-Page, P. C.; Klair, S. S.; Rosenthal, S. Chem.
Soc. Rev. 1990, 19, 147. (c) Cirillo, P. F.; Panek, J. S. Org.
Prep. Proced. Int. 1992, 24, 555.
3.1.26. 2-Acetyl-5-phenyl-(2E,4E)-pentadienoyltriphenyl-
silane (18). Following the previous procedure, (E)-2-acetyl-
7. (a) Reich, H. J.; Holtan, R. C.; Carsten, R. J. Am. Chem. Soc.
1990, 112, 5609. (b) Corey, E. J.; Luo, G.; Lin, L. S. Angew.

6276
A. Capperucci et al. / Tetrahedron 57 (2001) 6267±6276
Chem., Int. Ed. Engl. 1998, 37, 1126. (c). Corey, E. J.; Lin,
S. Z.; Luo, G. L. Tetrahedron Lett. 1997, 38, 5771.
18. Alexakis, A.; Commercon, A.; Coulentianos, C.; Normant,
J. F. Tetrahedron 1984, 40, 715.
19. Nowick, J. S.; Danheiser, R. L. J. Org. Chem. 1989, 54, 2798.
20. (a) Yamata, N.; Fujita, M.; Ogura, K. Bull. Chem. Soc. Jpn.
1990, 63, 3601. (b) Furber, M.; Herbert, J. M.; Taylor, R. J. K.
J. Chem. Soc., Perkin Trans 1 1989, 683. (c) Hartvigsen, K.;
Lund, P.; Hansen, L. F.; Holmer, G. Agric. Food Chem. 2000,
48, 4858. (d) Vernin, G.; Lageot, C.; Ghiglione, C.; Dahia, M.;
Parkanyi, C. J. Essent. Oil Res. 1999, 11, 673.
8. (a) Capperucci, A.; Degl'Innocenti, A. Recent Res. Devel.
Org. Chem. 1999, 3, 385. (b) Bonini, B. F.; Comes-Franchini,
M.; Fochi, M.; Mazzanti, G.; Ricci, A. J. Organomet. Chem.
1998, 567, 181.
9. (a) Reich, H. J.; Kelly, M. J.; Olson, R. E.; Holtan, R. C.
Tetrahedron 1983, 39, 949. (b) Tius, M. A.; Stergiades, I. A.
J. Org. Chem. 1999, 64, 7547 (and references cited therein).
(c) Delaude, L.; Masdeu, A. M.; Alper, H. Synthesis 1994,
1149. (d) Katritzky, A. R.; Lang, H. J. Org. Chem. 1995,
60, 7612. (e) Katritzky, A. R.; Feng, D.; Qi, M. J. Org.
Chem. 1998, 63, 147.
21. Soderquist, J. H.; Anderson, C. L. Tetrahedron Lett. 1988, 29,
2425 (also p. 2777).
22. (a) Fleming, I.; Newton, T. W.; Roessler, F. J. Chem. Soc.,
Perkin Trans 1 1981, 2527. (b) Lipshutz, B. H.; Ellsworth,
E. L.; Ditlock, S. H.; Reuter, D. G. Tetrahedron Lett. 1989, 30,
2065 (and references cited therein). (c) Singer, R. D.;
Hutzzinger, M. W.; Oehlschlager, A. C. J. Org. Chem. 1991,
56, 4993 (and references cited therein).
10. (a) Takeda, K.; Nakajima, A.; Takeda, M.; Okamoto, Y.; Sato,
T.; Yoshii, E.; Koizumi, T.; Shiro, M. J. Am. Chem. Soc. 1998,
120, 4947. (b) Takeda, K.; Nakane, D.; Takeda, M. Org. Lett.
2000, 2, 1903 (and references cited therein). (c) Narasaka, K.;
Kusama, H.; Hayashi, Y. Tetrahedron 1992, 48, 2059.
(d) Cunico, R. F.; Zhang, C. Tetrahedron 1995, 51, 9823.
(e) Buynak, J. D.; Geng, B.; Uang, S.; Strickland, J. B.
Tetrahedron Lett. 1994, 35, 985.
23. Degl'Innocenti, A.; Capperucci, A.; Bartoletti, L.; Mordini,
A.; Reginato, G. Tetrahedron Lett. 1994, 35, 2081.
24. Degl'Innocenti, A.; Capperucci, A.; Scafato, P.; Telesca, A.
Arkivoc 2000, 1, 452.
25. Howell, J. A. S.; O'Leary, P. J.; Yates, P. C.; Goldschmidt, Z.;
Gottlieb, H. E.; Hezroni-Langerman, D. Tetrahedron 1995,
51, 7231.
11. Ricci, A.; Degl'Innocenti, A.; Borselli, G.; Reginato, G.
Tetrahedron Lett. 1987, 28, 4093.
12. Ricci, A.; Degl'Innocenti, A.; Capperucci, A.; Reginato, G.;
Mordini, A. Tetrahedron Lett. 1991, 32, 1899.
26. Bellassoued, M.; Majidi, A. J. Org. Chem. 1993, 58, 2517.
27. Jeffery, T. Tetrahedron Lett. 1985, 26, 2667. Matsui, T.; Guth,
H.; Grosch, W. Fett/Lipid. 1998, 100, 51.
13. (a) Degl'Innocenti, A.; Stucchi, E.; Capperucci, A.; Mordini,
A.; Reginato, G.; Ricci, A. Synlett 1992, 329.
(b) Degl'Innocenti, A.; Stucchi, E.; Capperucci, A.; Mordini,
A.; Reginato, G.; Ricci, A. Synlett 1992, 332.
28. House, H. O.; Chu, C.-Y.; Wilkins, J. M.; Umen, M. J. J. Org.
Chem. 1975, 40, 1460.
29. House, H. O.; Wilkins, J. M. J. Org. Chem. 1978, 43, 2443.
30. Nilsson, M.; Wahren, R. J. Organomet. Chem. 1969, 16, 515.
31. Alexakis, A.; Cahiez, G.; Normant, J. F. Org. Synth. 1984, 62,
1.
14. Degl'Innocenti, A.; Capperucci, A.; Mordini, A.; Ricci, A.;
Reginato, G. Tetrahedron Lett. 1992, 33, 1507.
15. Treatment of 1 with TBAF in THF affords good yield of
propargylaldehyde.
32. Takai, K.; Nitta, K.; Utimoto, K. J. Am. Chem. Soc. 1986, 108,
7408.
16. (a) Corey, E. J.; Katzenellenbogen, J. A. J. Am. Chem. Soc.
1969, 91, 1831. (b) Siddall, J. B.; Biskup, M.; Fried, J. H.
J. Am. Chem. Soc. 1969, 91, 1853. (c) Klein, J.; Levene, R.
J. Chem. Soc., Perkin Trans 2 1973, 1971.
33. (a) Capella, L.; Degl'Innocenti, A.; Mordini, A.; Reginato, G.;
Ricci, A.; Seconi, G. Synthesis 1991, 1201. (b) Fujita, M.;
Chiba, K.; Nakano, J.; Tominaga, Y.; Matsumoto, J.-I.
Chem. Pharm. Bull. 1998, 46, 631.
17. Yamamoto, Y.; Yatagai, H.; Maruyama, K. J. Org. Chem.
1979, 44, 1744.