Regio- and stereoselectivity in the concatenated enyne cross metathesis-metallotropic [1,3]-shift of terminal 1,3-diyne This article is dedicated to Professor Paul A. Wender on the occasion of his receiving the 2012 Tetrahedron Prize for Creativity in Organic Chemistry

Article abstract of DOI:10.1016/j.tet.2013.08.024

Enyne cross metathesis of terminal 1,3-diynes with various alkenes afforded two products of distinctive connectivity, as the result of a uniform mode of initiation but different modes of termination events with or without metallotropic [1,3]-shift. Steric and electronic factors of the substituents on the 1,3-diynes play an important role in controlling the metallotropic [1,3]-shift of the propagating alkylidene intermediates and their regioselective trapping to the final products.

Full text of DOI:10.1016/j.tet.2013.08.024

Tetrahedron 69 (2013) 9105e9110
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Regio- and stereoselectivity in the concatenated enyne cross
metathesisemetallotropic [1,3]-shift of terminal 1,3-diyne
,
Kung-Pern Wang a, Eun Jin Cho b, Sang Young Yun a, Jee Young Rhee a, Daesung Lee a
*
a Department of Chemistry, University of Illinois at Chicago, 845 West Taylor Street, Chicago, IL 60607, United States
b Department of Chemistry and Applied Chemistry, Hanyang University, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan, Kyeonggi-do 426-791,
Republic of Korea
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 21 May 2013
Received in revised form 10 August 2013
Accepted 13 August 2013
Available online 20 August 2013
Enyne cross metathesis of terminal 1,3-diynes with various alkenes afforded two products of distinctive
connectivity, as the result of a uniform mode of initiation but different modes of termination events with
or without metallotropic [1,3]-shift. Steric and electronic factors of the substituents on the 1,3-diynes
play an important role in controlling the metallotropic [1,3]-shift of the propagating alkylidene in-
termediates and their regioselective trapping to the final products.
Ó 2013 Elsevier Ltd. All rights reserved.
This article is dedicated to Professor Paul A.
Wender on the occasion of his receiving the
2012 Tetrahedron Prize for Creativity in
Organic Chemistry
Keywords:
Enyne metathesis
Metallotropic shift
1,3-Diyne
1. Introduction
Enyne metathesis is a powerful synthetic tool to create 1,3-dienes
from alkynes and alkenes in an atom economical manner.1 While
enyne ring-closing metathesis has been applied to the synthesis of
various natural products and complex molecular frameworks,2 the
analogous intermolecular processes are employed to a significantly
lesser extent probably due to the lack of chemo- and stereoselectivity
as well as lower substrate generality.3e5 Thus the development of
new enyne cross metathesis that can not only expand the substrate
scope but also generate synthetically versatile building blocks is
highly desirable.
We previously reported ring-closing and cross metathesis of
various 1,3-diyne substrates6,7 catalyzed by ruthenium alkylidene
complex 18 (Scheme 1). In general, metallotropic [1,3]-shift was
ensued upon ring-closure of an alkylidene onto a 1,3-diyne moiety
(Eq. 1),9,10 whereas only cross metathesis without metallotropic
shift was observed in the cross metathesis of internal 1,3-diynes
and alkenes (Eq. 2).6a The lack of the metallotropic shift event in
Scheme 1. Enyne metathesis and metallotropic [1,3]-shift.
* Corresponding author. E-mail address: dsunglee@uic.edu (D. Lee).
0040-4020/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tet.2013.08.024

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K.-P. Wang et al. / Tetrahedron 69 (2013) 9105e9110
the latter case is the consequence of generating the propagating
alkylidene at the homopropargylic carbon rather than propargylic
carbon center. These differences clearly indicate that the inherently
favored regioselectivity of forming alkylidene carbene at the
homopropargylic carbon is switched over in the ring-closing me-
tathesis due to the constraint imposed by the tether to form the
kinetically favorable alkylidene carbene at the propargylic carbon,
which then undergoes metallotropic [1,3]-shift driven by steric
pressure around the propargylic carbon center or by thermody-
namic preference to form more fully conjugated end products.11 In
conjunction with these observations, we envision that the cross
metathesis of terminal 1,3-diyne 2 (R]H), where the regiochem-
istry of the initiation would also be reversed from that of internal
diynes such that intermediate 3 should be formed. This reversed
regiochemical preference is the consequence of the thermody-
namic preference of forming disubstituted alkylidene rather than
the mono-substituted one. Once formed, alkylidene 3 will be in
equilibrium with a new alkylidene species 30 via the metallotropic
[1,3]-shift, the respective termination of which would ultimately
generate structurally distinctive 2-alkynyl-1,3-diene 4 and 1,5-
diene-3-yne 5. We anticipated that the steric and electronic fac-
tors of the substituent R would affect the metallotropic [1,3]-shift,12
which in turn would influence the preference of the final trapping
[1,3]-shift, affording 2-alkynyl-3,4-diene 7a as a single regio- and
stereoisomer (entry 1). Considering relatively low E/Z-selectivity in
enyne cross metathesis, the formation of single stereoisomer of 7a
is noteworthy.14
While the substrate 6b possessing secondary alkyl group affor-
ded a 1:1 mixture of 7b and 8b (entry 2), primary alkyl group
substituted 1,3-diyne 6c afforded a mixture of 7c and 8c with
a 1:1.5 ratio (entry 3). Interestingly, the products 7aec formed
without metallotropic [1,3]-shift are all E-isomers, whereas prod-
ucts 8aec that were generated via metallotropic [1,3]-shift are
mixtures of E and Z isomers with varying ratios.
Next we examined substrates containing oxygen functionality at
the a-, b-, and g-carbon from the alkyne as a directing element for
metallotropic [1,3]-shift. 1,3-Diynes 6d and 6e containing the oxy-
gen substituent remote from the alkyne moiety, provided product
distributions similar to those of simple alkyl group substituted 1,3-
diynes (entries 4 and 5). Running the metathesis under the ethyl-
ene atmosphere15 did not improve the E-selectivity for 8d.16 While
the silyloxy substituent at the homopropargylic carbon in 6f did not
affect either the metallotropic [1,3]-shift or the E/Z-selectivity
(entry 6), the corresponding free hydroxyl group in 6g significantly
increased the metallotropic [1,3]-shift process to give a 1:4 mixture
of 7g and 8g (entry 7). Previously we reported that the conjugated
triyne substrate containing oxygen-based substituent at the prop-
argylic carbon undergoes facile metallotropic shift after ring-
closing enyne metathesis.12a Similarly, the oxygen substituent at
the propargylic carbon in 6h promoted metallotropic [1,3]-shift
effectively, providing single regioisomer 8h as a mixture of E/Z-
isomers (entry 8).12 Terminal triyne 6i provided similar reactivity
with slightly diminished yield compared to substrate 6d.
process. Herein we report
a tandem enyne cross meta-
thesisemetallotripic [1,3]-shift process of terminal 1,3-diynes and
its regio- and stereoselectivity profiles.
2. Result and discussion
First, the effect of the substituents on the diynes were examined
with terminal diyne13 substrates 6aeh and triyne substrate 6i with
allyl acetate as the alkene counterpart (Table 1). The product dis-
tribution from these reactions is consistent with the combined ef-
fect of both steric and electronic factors. The diyne substrate 6a
containing triisopropylsilyl group did not undergo metallotropic
Next we explored the effect of protecting groups on the prop-
argylic hydroxyl group employing 1ꢀ, 2ꢀ, 3ꢀ propargylic alcohols
and their protected derivatives (Table 2).
The CM of 1,3-diyne substrate 6j containing 1ꢀ propargylic hy-
droxyl group provided only 8j in 69% yield (entry 1), but that of its
Table 1
Reaction scope for enyne metathesis and metallotropic [1,3]-shift
Table 2
Propargylic hydroxyl group-directed enyne metathesis and metallotropic [1,3]-shift
Entry
1
Substrate
7:8 (E/Z of 8)a
Yield %b
47c
Entry
1b
1,3-Diyne
7:8 (E/Z of 8)
0:1 (1:0.8)
Yield %a
69
6a
6b
1:0
6j
2
1:1 (1:4)
73
2
6k
1:10 (1:0.9)
84
3
6c
6d
6e
1:1.5 (1:2)
79
80
67
3b
4
6l
0:1 (1:0.9)
0:1 (1:0.9)
71
75
4d
5e
1:1.3 (1:2.3)
1:1.6 (1:1.3)
6m
6
6f
1:1.5 (1:2)
1:4 (1:3)
81
73
77
5
6
7
6n
6o
6p
1:1.7 (1:2)
1:1.3 (1:2)
1:5.5 (1:1.7)
79
74
42
7e
8
6g
6h
0:1 (1.2:1)
9f
6I
1:1.4 (1:2.4)
41
a
Ratio was determined by 1H NMR (See Supplementary data).
Combined yields of a mixture of three isomers after column chromatography.
40% of 6a was recovered.
Introduction of 20 psi of ethylene gives similar ratio and yield.
5% of HOAc was added into the reaction.17
R¼TBSO(CH2)3C^C.
b
c
d
e
f
8
6q
0:1 (1:4)
69
a
Combined yields of a mixture of three isomers after column chromatography.
5% of HOAc was added into the reaction.17
b

K.-P. Wang et al. / Tetrahedron 69 (2013) 9105e9110
9107
benzyl ether derivative 6k generated a 1:10 mixture of 7k and 8k
(entry 2). 1,3-Diyne substrates containing 2ꢀ hydroxyl group and its
trimethylsilyl ether derivative afforded metallotropic [1,3]-shifted
products 8l and 8m as a mixture of E/Z-isomers (entries 3 and 4).
On the other hand, the corresponding t-butyldimethylsilyl and
benzyl protected substrates 6n and 6o afforded a 1:1.7 and 1:1.3
mixture of 7n/8n and 7o/8o, respectively (entries 5 and 6). Sub-
strates containing 3ꢀ hydroxyl group favor metallotropic [1,3]-shift,
providing high selectivity (entries 7 and 8).
Having identified the heteroatom effect on 1,3-diynes that af-
fects metallotropic [1,3]-shift, we also examined the effect of het-
eroatom substituent at the allylic carbon of the alkene counterpart
(Table 3). Metathesis reaction of 1,3-diyne 6d with tolyl and
pivaloyl-protected allylic alcohol derivatives 9a, 9b showed almost
the same product distribution as that with allyl acetate, affording
10a, 11a, and 10b, 11b in a 1:1.5 and 1:1.3 ratio, respectively (entries
1 and 2). However, the yields with allyl pivalate (39%) and allyl tolyl
ether (56%) are much lower compared to that with allyl acetate
(80%). Surprisingly, the reaction with allyl alcohol 9c gave only
a trace amount of cross metathesis product and 1,3-diyne substrate
6c was recovered (entry 3).14 Allyl trimethylsilane 9d promoted
slightly favorable metallotropic [1,3]-shift, providing 10d and 11d in
a 1:2.6 ratio in 76% yield (entry 4), whereas with ethylene 9e
completely suppressed the metallotropic [1,3]-shift, affording only
10e but in low conversion (entry 5).
Scheme 2. Rational for the observed product distribution.
than that of C. For alkylidene intermediate B carrying Z-alkene
substituent, unfavorable steric interaction between the substituent
R2 and the sterically bulky ruthenium center promotes its metal-
lotropic [1,3]-shift to another alkylidene D. Selective termination
from D generates final product G containing a Z-alkene moiety.
Table 3
Cross metathesis with alkenes with different allylic substituents
3. Conclusion
In summary, we have investigated a concatenated enyne
cross metathesisemetallotropic [1,3]-shift employing terminal 1,3-
diynes and alkenes, and for the first time, metallotropic [1,3]-shift
was promoted by cross metathesis. The regioselectivity of the ini-
tial propagating alkylidene formation could be reversed relative to
the corresponding internal 1,3-diynes so that metallotropic [1,3]-
shift behavior could be examined. As opposed to the invariably
favorable metallotropic [1,3]-shift observed in the ring-closing
metathesis of 1,3-diynes containing tethered alkene, the extent of
metallotropic [1,3]-shift is significantly affected by steric and elec-
tronic effects of the substituent on propargylic carbon of 1,3-diynes.
This unprecedented enyne cross metathesis of 1,3-diynes involving
the predictable behavior of metallotropic [1,3]-shift of the in-
termediate propagating alkylidene species would provide guidance
in the design of more efficient substrates for tandem enyne cross
metathesis and metallotropic [1,3]-shift.
Entry
R in alkene
10:11 (E/Z of 11)
Yield %
1
2
3
4
5
CH2OTol
CH2OPiv
CH2OH
CH2SiMe3
H
9a
9b
9c
9d
9e
1:1.5 (1:2)
1:1.3 (1:2.3)
N/A
1:2.6 (1:2)
1:0
56a
39a
0
76b
29c
a
Yield was determined by 1H NMR with internal standard after short column
purification.
b
c
Isolated yield.
20 psi of ethylene was introduced and 60% of 6e was recovered.
Overall, it was found that the substituent pattern on diyne sig-
nificantly affects the regioselectivity of the metallotropic [1,3]-shift,
whereas the influence of substituent on alkene is marginal. Spe-
cifically, the introduction of silyl group on terminal diyne ensures
the formation of E-2-alkynyl-3,4-diene. While the oxygen sub-
stituent remote from alkyne does not exert a noticeable influence
on metallotropic shift behavior, propargylic hydroxyl group mark-
edly facilitates metallotropic shift. The choice of protecting group of
propargylic hydroxyl group in substrate design is also critical to
obtain a single regioisomer.
A reasonable explanation for the product distribution with and
without metallotropic [1,3]-shift is depicted in Scheme 2. Cross
metathesis of a 1,3-diyne with an alkene initiated by ruthenium
alkylidene would lead to two E/Z-isomeric new ruthenium alkyli-
dene intermediates A and B. While A equilibrates with C via met-
allotropic [1,3]-shift, its termination provides F, whereas
termination of C leads to E. When R1 possesses oxygen-based
substituent at the propargylic carbon center, [1,3]-shift is facili-
tated most likely because of the favorable chelation event between
the oxygen and the ruthenium center. If R1 is sterically hindered, A
is more favorable than C and also its termination should be faster
4. Experimental section
4.1. General
Compounds were purchased from Aldrich unless otherwise
noted. CH2Cl2 were purified based on standard procedures. Flash
ꢀ
chromatography was performed using silica gel 60 A (32e63 mesh)
purchased from Sorbent Technologies. Analytical thin layer chro-
matography (TLC) was performed on 0.25 mm E. Merck pre-coated
silica gel 60 (particle size 0.040e0.063 mm). 1H NMR and 13C NMR
spectra were recorded on a Bruker AV-500 MHz or Varian Mercury
300 MHz spectrometer. Multiplicities are indicated by s (singlet),
d (doublet), t (triplet), q (quartet), qn (quintet), m (multiplet), and
br (broad). Coupling constants, J, are reported in Hertz. Electron
impact (EI) mass spectra were obtained using a Micromass Auto-
SpecTM at the Mass Spectrometry Laboratory in the University of
Illinois at Urbana-Champaign.

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K.-P. Wang et al. / Tetrahedron 69 (2013) 9105e9110
4.2. General procedure for cross enyne metathesis
18.3, 15.7, ꢁ5.3, ꢁ5.4; HRMS (EI) calcd for C18H31O3Si [MþH]þ:
323.2043, found 323.2061.
In a flame dried Schlenk tube, 1,3-diyne (1 equiv), allyl acetate
(5 equiv), and Grubbs second-generation catalyst (8 mol %) were
dissolved in anhydrous CH2Cl2. The reaction mixture was degassed
under vacuum and re-filled with nitrogen gas. The tube was then
stirred in an oil bath at 40 ꢀC for 6 h (Warning: reaction might be
explosive due to the internal pressure build up in the sealed tube).
After 6 h, the tube was opened to the air at room temperature and
the solvent was removed by the rotary aspirator. The organic
product was isolated by column chromatography on silica gel
(EtOAc/hexane) to afford the cross metathesis product.
4.2.5. (E)-9-Hydroxy-4-methylenenon-2-en-5-ynyl acetate (7e) and
9-hydroxy-6-methylenenon-2-en-4-ynyl acetate (8eþ8e0). Pale yel-
low oil, 1H NMR (501 MHz, CDCl3) 7e:
d
6.25 (d, J¼15.4 Hz, 1H), 5.97
(td, J¼6.6, 10.8 Hz, 1H), 5.42 (s, 1H), 5.35 (s, 1H), 4.62 (d, J¼6.1 Hz,
2H), 3.74 (t, J¼6.1 Hz, 2H), 2.46 (t, J¼7.0 Hz, 2H), 2.06 (s, 3H),1.79 (m,
2H); 8eþ8e0: 6.14e6.09 (m, 2H), 5.84 (8e, d, J¼15.9 Hz, 1H), 5.77
(8e0, d, J¼10.8 Hz, 1H), 5.34 (8e0, s, 1H), 5.32 (8e, s, 1H), 5.28 (8e0, s,
1H), 5.26 (8e, s, 1H), 4.81 (8e0, dd, J¼1.1, 6.6 Hz, 2H), 4.58 (8e, dd,
J¼1.3, 6.0 Hz, 2H), 3.67e3.61 (m, 4H), 2.28e2.22 (m, 4H), 2.05 (s,
6H), 1.82e1.71 (m, 4H); 13C NMR (126 MHz, CDCl3)
d 170.9, 170.8,
4.2.1. (E)-4-Methylene-6-(triisopropylsilyl)hex-2-en-5-ynyl acetate
170.5, 144.8, 142.1, 136.1, 135.6, 133.4, 130.8, 128.9, 126.9, 123.6,
122.1, 121.9, 113.4, 112.9, 96.2, 93.3, 91.9, 91.0, 86.7, 84.4, 77.4, 64.1,
63.9, 62.2, 61.8, 61.7, 61.5, 33.3, 31.3, 31.1, 31.0, 20.8, 20.7,15.7; HRMS
(EI) calcd for C12H16O3 [M]þ: 208.1099, found 208.1105.
(7a). Yellow oil, 1H NMR (501 MHz, CDCl3)
d
6.27 (d, J¼15.4 Hz, 1H),
6.20 (td, J¼5.8, 15.3 Hz, 1H), 5.56 (s, 1H), 5.44 (s, 1H), 4.66 (d,
J¼5.7 Hz, 2H), 2.08 (s, 3H), 1.01 (s, 21H); 13C NMR (126 MHz, CDCl3)
d
170.7, 132.7, 129.0, 127.6, 124.9, 64.7, 64.4, 64.1, 20.6, 18.7, 11.3;
HRMS (EI) calcd for C18H30O2Si [M]þ: 306.2015, found 306.2022.
4.2.6. (E)-8-(tert-Butyldimethylsilyloxy)-4-methyleneoct-2-en-5-
ynyl acetate (7f) and 8-(tert-butyldimethylsilyloxy)-6-methylene-oct-
2-en-4-ynyl acetate (8fþ8f0). Colorless oil, 1H NMR (501 MHz,
4.2.2. (E)-6-Cyclohexyl-4-methylenehex-2-en-5-ynyl acetate (7b)
and 6-cyclohexylhepta-2,6-dien-4-ynyl acetate (8bþ8b0). Pale yel-
CDCl3) 7f:
d
6.26 (d, J¼15.4 Hz,1H), 5.98 (td, J¼6.6, 10.9 Hz,1H), 5.45
1
low oil, H NMR (501 MHz, CDCl3) 7bþ8bþ8b0:
d
6.27 (7b, d,
(s, 1H), 5.37 (s, 1H), 4.64 (d, J¼6.0 Hz, 2H), 3.77 (m, 2H), 2.57 (d,
J¼7.0 Hz, 2H), 2.07 (s, 3H), 0.89 (s, 9H), 0.07 (s, 6H), 8fþ8f0:
6.19e6.09 (m, 2H), 5.85 (8f, d, J¼15.9 Hz, 1H), 5.78 (8f0, d, J¼10.8 Hz,
1H), 5.41 (8f0, s, 1H), 5.38 (8f, s, 1H), 5.32 (8f0, s, 1H), 5.29 (8f, s, 1H),
4.81 (8f0, dd, J¼1.3, 6.6 Hz, 2H), 4.61 (8f, dd, J¼1.4, 6.1 Hz, 2H),
3.79e3.73 (m, 4H), 2.41e2.34 (m, 4H), 2.07 (8f, s, 3H), 2.06 (8f0, s,
3H), 0.88 (8f, s, 9H), 0.87 (8f0, s, 9H), 0.05 (8f, s, 6H), 0.04 (8f0, s, 6H);
J¼15.4 Hz, 1H), 6.17e6.10 (8bþ8b0, m, 2H), 5.97 (7b, td, J¼6.6,
10.9 Hz, 1H), 5.87 (8b, d, J¼16.0 Hz, 1H), 5.78 (8b0, d, J¼10.8 Hz, 1H),
5.43 (7b, s,1H), 5.35 (7b, s,1H), 5.29 (8b0, s,1H), 5.27 (8b, s,1H), 5.25
(8b0, s, 1H), 5.23 (8b, s, 1H), 4.83 (8b0, d, J¼6.6 Hz, 2H), 4.64 (7b, d,
J¼6.1 Hz, 2H), 4.60 (8b, d, J¼6.1 Hz, 2H), 2.53 (7b, m, 1H), 2.08 (7b, s,
3H), 2.08e2.02 (8bþ8b0, m, 2H), 2.06 (8bþ8b0, s, 6H), 1.51e1.09
(7bþ8bþ8b0, m, 30H); 13C NMR (126 MHz, CDCl3)
d
170.67, 170.63,
13C NMR (126 MHz, CDCl3)
d 170.66, 170.64, 136.0, 135.7, 133.2,
170.5, 137.2, 135.7, 135.4, 133.5, 129.1, 126.8, 122.2, 119.7, 119.4, 113.7,
113.1, 97.0, 96.2, 94.7, 76.8, 64.1, 64.0, 62.3, 44.8, 32.6, 31.9, 29.5,
26.2, 25.9, 25.8, 24.9, 20.9, 20.8; HRMS (EI) calcd for C15H20O2 [M]þ:
232.1463, found 232.1470.
128.9, 128.2, 128.1, 127.1, 123.60, 123.59, 123.4, 113.5, 112.9, 96.3,
91.2, 89.7, 86.5, 84.2, 78.0, 64.1, 63.9, 62.2, 61.8, 61.6, 61.5, 40.60,
40.56, 30.3, 25.88, 25.84, 23.7, 20.9, 20.8,18.3, ꢁ5.3; HRMS (EI) calcd
for C17H28O3Si [M]þ: 308.1808, found 308.1793.
4.2.3. (E)-4-Methylenedec-2-en-5-ynyl acetate (7c) and 6-
methylenedec-2-en-4-ynyl acetate (8cþ8c0). Colorless oil, 1H NMR
4.2.7. (E)-8-Hydroxy-4-methyleneoct-2-en-5-ynyl acetate (7g) and
8-hydroxy-6-methyleneoct-2-en-4-ynyl acetate (8gþ8g0). Pale yel-
(501 MHz, CDCl3)
d
6.24 (7c, d, J¼15.3 Hz, 1H), 6.15e6.08 (8cþ8c0,
low oil, 1H NMR (501 MHz, CDCl3)
d
6.27 (7g, d, J¼15.4 Hz, 1H),
m, 2H), 5.84 (8c, d, J¼15.9 Hz, 1H), 5.76 (8c0, d, J¼10.8 Hz, 1H), 5.41
(7c, s, 1H), 5.32 (7c, s, 1H), 5.30 (8c0, s, 1H), 5.28 (8c0, s, 1H), 5.22 (8c0,
s, 1H), 5.20 (8c, s, 1H), 4.80 (8c0, dd, J¼1.3, 6.6 Hz, 2H), 4.62 (7c, d,
J¼6.1 Hz, 2H), 4.58 (8c, dd, J¼1.4, 6.1 Hz, 2H), 2.33 (7c, t, J¼7.1 Hz,
2H), 2.17e2.10 (8cþ8c0, m, 4H), 2.05 (7c, s, 3H), 2.03 (8cþ8c0, s, 6H),
1.56e1.24 (7cþ8cþ8c0, m, 18H), 0.92e0.84 (7cþ8cþ8c0, m, 9H); 13C
6.20e6.10 (7gþ8g, m, 2H), 5.84 (8g, d, J¼15.9 Hz, 1H), 5.79 (8g0, d,
J¼10.8 Hz, 1H), 5.48 (7g, s, 1H), 5.47 (8g0, s, 1H), 5.45 (8g, s, 1H), 5.40
(7g, s, 1H), 5.38 (8g0, s, 1H), 5.36 (8g, s, 1H), 4.82 (8g0, dd, J¼0.9,
6.7 Hz, 1H), 4.64 (7g, d, J¼6.1 Hz,1H), 4.61 (8g, dd, J¼1.2, 6.0 Hz, 1H),
2.66e2.62 (8gþ8g0, m, 4H), 2.57 (7g, t, J¼6.2 Hz, 2H), 2.46e2.40
(7gþ8gþ8g0, m, 6H), 2.08 (7g, s, 3H), 2.07 (8gþ8g0, s, 6H); 13C NMR
NMR (126 MHz, CDCl3)
d
170.52, 170.47, 170.3, 144.5, 141.7, 135.8,
(126 MHz, CDCl3) d 170.8, 170.7, 167.2, 142.6, 136.6, 136.1, 133.1,
135.5, 133.4, 131.5, 126.9, 126.5, 123.1, 121.4, 121.2, 113.5, 112.8, 96.6,
96.1, 93.4, 62.8, 91.4, 86.3, 84.0, 76.9, 64.0, 63.9, 62.2, 36.7, 36.69,
36.65, 30.7, 30.2, 21.9, 20.8, 20.7, 18.8, 13.7, 13.5; HRMS (EI) calcd for
128.6, 127.8, 127.1, 124.2, 124.1, 124.0, 113.1, 112.8, 110.8, 95.6, 93.0,
84.8, 78.8, 75.3, 64.1, 62.2, 61.1, 60.9, 60.7, 60.6, 40.3, 30.3, 24.0, 23.6,
20.8; HRMS (EI) calcd for C11H14O3 [M]þ: 194.0943, found 194.0928.
C
14H20O2 [M]þ: 220.1463, found 220.1474.
4.2.8. 6-((tert-Butyldimethylsilyloxy)methyl)hepta-2,6-dien-4-ynyl
4.2.4. (E)-9-(tert-Butyldimethylsilyloxy)-4-methylenenon-2-en-5-
ynyl acetate (7d) and 9-(tert-butyldimethylsilyloxy)-6-methylene-
non-2-en-4-ynyl acetate (8dþ8d0). Colorless oil, 1H NMR (501 MHz,
acetate (8hþ8h0). Pale yellow oil, 1H NMR (501 MHz, CDCl3)
d 6.16
(8h, td, J¼6.0,15.9 Hz,1H), 5.99 (8h0, td, J¼6.6,10.9 Hz,1H), 5.85 (8h,
d, J¼15.9 Hz, 1H), 5.78 (8h0, d, J¼10.9 Hz, 1H), 5.62 (8h0, dd, J¼1.9,
3.8 Hz, 1H), 5.60 (8h, dd, J¼1.8, 3.7 Hz, 1H), 5.48 (8h0, dd, J¼1.8,
3.5 Hz, 1H), 5.45 (8h, dd, J¼1.7, 3.4 Hz, 1H), 4.82 (8h0, dd, J¼1.4,
6.6 Hz, 2H), 4.61 (8h, dd, J¼1.5, 6.0 Hz, 2H), 4.16 (8h0, t, J¼1.8, 2H),
4.14 (8h, t, J¼1.7 Hz, 2H), 2.07 (8hþ8h0, s, 6H), 0.90 (8hþ8h0, s, 18H),
CDCl3) 7d:
d
6.28 (d, J¼15.3 Hz, 1H), 6.15 (td, J¼6.1, 15.2 Hz, 1H), 5.45
(s, 1H), 5.37 (s, 1H), 4.65 (d, J¼6.1 Hz, 2H), 3.72 (t, J¼6.1 Hz, 1H), 2.46
(t, J¼7.1 Hz, 1H), 2.09 (s, 3H), 1.78 (m, 2H), 0.90 (s, 9H), 0.06 (s, 6H),
8dþ8d0:
d
6.15 (8d, td, J¼6.1, 15.9 Hz, 1H), 5.98 (8d0, td, J¼6.6,
10.8 Hz, 1H), 5.87 (8d, d, J¼15.8 Hz, 1H), 5.79 (8d0, d, J¼10.8 Hz, 1H),
5.36 (8d0, s, 1H), 5.33 (8d, s, 1H), 5.29 (8d0, s, 1H), 5.27 (8d, s, 1H),
4.83 (8d0, dd, J¼1.2, 6.6 Hz, 2H), 4.61 (8d, dd, J¼1.4, 6.1 Hz, 2H),
3.66e3.59 (m, 4H), 2.29e2.21 (m, 4H), 2.08 (s, 6H), 1.79e1.70 (m,
0.08 (8hþ8h0, s, 12H); 13C NMR (126 MHz, CDCl3)
d 170.7, 170.4,
136.4, 136.0, 130.70, 130.66, 119.99, 119.74, 113.3, 112.6, 94.0, 88.9,
87.6, 85.3, 64.9, 64.8, 63.9, 62.3, 25.8, 20.8, 18.4, ꢁ5.4; HRMS (EI)
calcd for C16H25O3Si [MꢁH]þ: 293.1573, found 293.1582.
4H), 0.89 (s, 18H), 0.05 (s, 12H); 13C NMR (126 MHz, CDCl3)
d 170.68,
170.64, 170.5, 144.7, 141.8, 136.0, 135.7, 134.2, 133.4, 131.1, 131.0,
129.1, 128.6, 128.0, 126.9, 126.6, 125.5, 123.4, 123.2, 121.9, 121.7,
113.5, 112.9, 96.5, 93.6, 92.4, 91.3, 86.5, 84.2, 65.0, 64.9, 63.9, 62.2,
62.1, 62.0, 61.6, 33.4, 31.7, 31.1, 30.3, 29.7, 25.9, 20.89, 20.82, 20.79,
4.2.9. (E)-11-(tert-Butyldimethylsilyloxy)-4-methyleneundeca-2-en-
5,7-diynyl acetate (7i) and 11-(tert-butyldimethylsilyloxy)-8-
methyleneundeca-2-en-4,6-diynyl acetate (8iþ8i0). Pale yellow oil,
1H NMR (501 MHz, CDCl3) 7i:
d
6.26 (d, J¼15.4 Hz, 1H), 6.16 (m, 1H),

K.-P. Wang et al. / Tetrahedron 69 (2013) 9105e9110
9109
5.62 (s,1H), 5.53 (s,1H), 4.65 (d, J¼5.9 Hz, 2H), 3.69 (t, J¼5.9 Hz, 2H),
2.43 (t, J¼7.1 Hz, 2H), 2.09 (s, 3H), 1.72 (m, 2H), 0.89 (s, 9H), 0.06 (s,
6H); 8iþ8i0: 6.29 (8i, td, J¼5.8, 15.9 Hz, 1H), 6.14 (8i0, td, J¼6.5,
11.0 Hz, 1H), 5.82 (8i, td, J¼1.6, 15.9 Hz, 1H), 5.77 (8i0, td, J¼1.5,
11.0 Hz, 1H), 5.50 (8i0, s, 1H), 5.49 (8i, s, 1H), 5.42 (8i0, d, J¼1.5 Hz,
1H), 5.40 (8i, d, J¼1.6 Hz, 1H), 4.84 (8i0, dd, J¼1.5, 6.5 Hz, 2H), 4.63
(8i, dd, J¼1.6, 5.8 Hz, 2H), 3.62 (8i0, t, J¼6.2 Hz, 2H), 3.61 (8i, t,
J¼6.2 Hz, 2H), 2.25 (m, 2H), 2.08 (s, 3H), 1.74 (m, 2H), 0.89 (s, 9H),
oct-2-en-4-ynyl acetate (8nþ8n0). Colorless oil, 1H NMR (501 MHz,
CDCl3)
d
6.26 (7n, d, J¼15.4 Hz, 1H), 6.14 (8nþ8n0, m, 2H), 5.98 (7n,
td, J¼6.6, 10.9 Hz, 1H), 5.87 (8n, d, J¼15.9 Hz, 1H), 5.79 (8n0, d,
J¼10.8 Hz,1H), 5.58 (8n, s, 1H), 5.57 (8n0, s,1H), 5.47 (8n, s, 1H), 5.40
(7n, s, 2H), 5.38 (8n0, s, 1H), 4.83 (8n0, d, J¼6.8 Hz, 1H), 4.68 (7n, dd,
J¼6.5, 13.2 Hz, 1H), 4.64 (7n, d, J¼6.0 Hz, 2H), 4.61 (8n, d, J¼7.5 Hz,
2H), 4.31e4.24 (8nþ8n0, m, 4H), 2.07 (s, 3H), 2.06 (s, 6H), 1.46 (d,
J¼6.5 Hz, 3H), 1.32 (d, J¼6.5 Hz, 3H), 1.30 (d, J¼6.7 Hz, 3H), 0.90 (s,
9H), 0.89 (s, 18H), 0.12 (d, J¼4.6 Hz, 6H), 0.06 (d, J¼6.3 Hz, 6H), 0.05
0.04 (s, 6H); 13C NMR (126 MHz, CDCl3)
d 170.6, 170.4, 139.8, 139.6,
134.2, 132.2, 130.2, 128.6, 128.1, 127.8, 126.6, 126.4, 125.2, 125.0,
124.8, 123.2, 112.0, 111.6, 84.7, 83.8, 82.4, 80.1, 78.7, 76.3, 75.2, 73.4,
73.2, 71.3, 65.1, 64.8, 63.9, 63.6, 62.4, 61.9, 61.3, 33.1, 33.0, 31.2, 31.1,
26.1, 25.9, 20.9, 20.8, 18.3, 16.2, 16.0, ꢁ5.3, ꢁ5.5; HRMS (EI) calcd for
(d, J¼5.2 Hz, 6H); 13C NMR (126 MHz, CDCl3)
d 170.65, 170.56, 136.1,
135.8, 132.7, 128.5, 127.3, 124.0, 119.7, 119.4, 113.5, 112.8, 94.6, 94.3,
89.5, 85.9, 79.8, 70.6, 70.5, 63.97, 63.91, 62.3, 59.3, 30.3, 25.8, 25.4,
23.9, 20.8, 18.2, ꢁ4.6, ꢁ4.9, ꢁ5.0; HRMS (CI) calcd for C16H25O3Si
[MꢁCH3]þ: 293.1573, found 293.1568.
C
20H30O3Si [M]þ: 346.1964, found 346.1969.
4.2.10. 6-(Hydroxymethyl)hepta-2,6-dien-4-ynyl acetate (8jþ8j0).
4.2.15. (E)-7-(Benzyloxy)-4-methyleneoct-2-en-5-ynyl acetate (7o)
and 7-(benzyloxy)-6-methyleneoct-2-en-4-ynyl acetate (8oþ8o0).
Colorless oil, 1H NMR (501 MHz, CDCl3) 8j:
d
6.19 (td, J¼6.0, 15.9 Hz,
1H), 5.87 (d, J¼15.9 Hz, 1H), 5.56 (s, 1H), 5.49 (s, 1H), 4.62 (d,
J¼5.3 Hz, 2H), 4.15 (d, J¼6.1 Hz, 2H), 2.08 (s, 3H), 1.76 (t, J¼6.3 Hz,
1H); 8j0: 6.03 (td, J¼6.7, 10.9 Hz, 1H), 5.81 (d, J¼10.9 Hz, 1H), 5.57 (s,
1H), 5.51 (s, 1H), 4.84 (d, J¼6.7 Hz, 2H), 4.18 (d, J¼6.3 Hz, 2H), 2.08
Yellow oil, 1H NMR (501 MHz, CDCl3)
d
7.43e7.24 (7oþ8oþ8o0, m,
15H), 6.31 (7o, d, J¼15.4 Hz, 1H), 6.24e6.14 (7oþ8o, m, 2H), 6.03
(8o0, td, J¼6.6, 10.9 Hz, 1H), 5.59e5.46 (7oþ8oþ8o0, m, 6H), 4.87
(8o0, d, J¼6.3 Hz, 2H), 4.82 (8o, d, J¼6.3 Hz, 2H), 4.68 (7o, d,
J¼6.3 Hz, 2H), 4.65e4.59 (7oþ8oþ8o0, m, 4H), 4.41 (7o, dd, J¼6.6,
13.3 Hz, 2H), 4.39e4.33 (7oþ8oþ8o0, m, 3H), 4.03e3.95 (8oþ8o0,
m, 2H), 2.09 (7o, s, 3H), 2.086 (8o, s, 3H), 2.076 (8o0, s, 3H), 1.55 (7o,
d, J¼6.6 Hz, 3H), 1.42e1.38 (8oþ8o0, m, 6H); 13C NMR (126 MHz,
(s, 3H), 2.01 (t, J¼6.4 Hz, 1H); 13C NMR (126 MHz, CDCl3)
d 170.8,
170.5, 136.9, 136.3, 131.0, 121.1, 120.9, 113.0, 112.8, 93.7, 88.5, 88.3,
86.0, 65.32, 65.26, 63.9, 62.1, 20.88, 20.81; HRMS (EI) calcd for
C
10H11O3 [MꢁH]þ: 179.0708, found 179.0717.
CDCl3) d 170.6, 170.5, 170.3, 138.3, 137.9, 136.5, 136.2, 133.34, 133.29,
4.2.11. (E)-7-(Benzyloxy)-4-methylenehept-2-en-5-ynyl acetate (7k)
and 6-(benzyloxymethyl)hepta-2,6-dien-4-ynyl acetate (8kþ8k0).
132.7, 128.32, 128.27, 128.2, 127.9, 127.7, 127.43, 127.36, 124.6, 122.2,
122.0, 113.3, 112.7, 93.7, 91.5, 88.6, 88.4, 86.1, 81.7, 77.2, 70.6, 70.2,
64.8, 63.9, 63.8, 62.2, 22.1, 21.0, 20.83, 20.78; HRMS (EI) calcd for
Yellow oil, 1H NMR (501 MHz, CDCl3)
d
7.40e7.23 (7kþ8kþ8k0, m,
15H), 6.30 (7k, d, J¼15.4 Hz, 1H), 6.23e6.15 (7kþ8k, m, 2H), 6.02
(8k0, td, J¼6.6, 11.0 Hz, 1H), 5.88 (8k, d, J¼15.9 Hz, 1H), 5.80 (8k0, d,
J¼10.9 Hz, 1H), 5.64e5.58 (m, 6H), 4.84 (8k0, d, J¼6.6 Hz, 1H), 4.67
(7k, d, J¼5.9 Hz, 1H), 4.62 (8k, d, J¼6.0 Hz, 1H), 4.57 (7kþ8kþ8k0, s,
6H), 4.06 (7kþ8kþ8k0, s, 6H), 2.09 (7k, s, 3H), 2.08 (8k, s, 3H), 2.07
C
18H19O3 [MꢁH]þ: 283.1334, found 283.1351.
4.2.16. (E)-7-Hydroxy-7-methyl-4-methyleneoct-2-en-5-ynyl acetate
(7p) and 7-hydroxy-7-methyl-6-methyleneoct-2-en-4-ynyl acetate
(8pþ8p0). Yellow oil, 1H NMR (501 MHz, CDCl3)
d 6.27 (7p, d,
(8k0, s, 3H); 13C NMR (126 MHz, CDCl3)
d
170.6, 170.5, 170.4, 137.9,
J¼6.6 Hz, 1H), 6.21e6.07 (7pþ8p, m, 2H), 6.01 (8p0, td, J¼6.7, 10.8 Hz,
1H), 5.89 (8p, d, J¼15.9 Hz, 1H), 5.82 (8p0, d, J¼10.8 Hz, 1H), 5.62 (8p0,
J¼1.2 Hz, 1H), 5.60 (8p, J¼1.2 Hz, 1H), 5.50 (7p, s, 1H), 5.43 (8p0, d,
J¼0.8 Hz,1H), 5.41 (8p, d, J¼1.0 Hz,1H), 5.40 (7p, s,1H), 4.83 (8p0, dd,
J¼1.5, 6.0 Hz, 2H), 4.65 (7p, d, J¼6.1 Hz, 2H), 4.62 (8p, dd, J¼1.5,
6.0 Hz, 2H), 2.09 (7p, s, 3H), 2.08 (8p, s, 3H), 2.07 (8p0, s, 3H),1.58 (7p,
s, 6H), 1.44 (8p0, s, 6H), 1.42 (8p, s, 6H); 13C NMR (126 MHz, CDCl3)
136.6, 136.3, 132.5, 128.3, 128.23, 128.18, 128.0, 127.64, 127.61, 127.5,
124.8, 122.5, 122.3, 113.1, 112.5, 94.2, 89.1, 87.6, 85.3, 72.13, 72.08,
71.6, 63.9, 63.8, 62.2, 57.6, 20.8, 20.75, 20.71; HRMS (EI) calcd for
C
17H17O3 [MꢁH]þ: 269.1178, found 269.1168.
4.2.12. 7-Hydroxy-6-methyleneoct-2-en-4-ynyl acetate (8lþ8l0).
Colorless oil, 1H NMR (501 MHz, CDCl3) 8l:
d
6.16 (td, J¼6.0, 15.8 Hz,
d 170.7, 170.6, 170.5, 145.6, 142.7, 139.4, 136.4, 136.0, 132.8, 129.3,
1H), 5.85 (d, J¼15.9 Hz, 1H), 5.50 (s, 1H), 5.39 (s, 1H), 4.59
(d, J¼6.0 Hz, 2H), 4.29 (m, 1H), 2.26 (br, 1H), 2.05 (s, 3H), 1.33
(d, J¼6.5 Hz, 3H); 8l0: 5.99 (td, J¼6.7, 10.9 Hz,1H), 5.77 (d, J¼10.8 Hz,
1H), 5.52 (s, 1H), 5.41 (s, 1H), 4.81 (d, J¼6.7 Hz, 2H), 4.28 (m, 1H),
2.43 (br, 1H), 2.04 (s, 3H), 1.35 (d, J¼6.6 Hz, 3H); 13C NMR
128.2, 127.2, 125.5, 124.5, 119.1, 118.8, 113.3, 113.0, 94.4, 92.6, 89.2,
88.7, 86.5, 72.7, 72.6, 64.0, 63.9, 62.1, 31.5, 31.4, 30.9, 30.3, 29.1, 20.94,
20.87; HRMS (EI) calcd for C12H16O3 [M]þ: 208.1100, found 208.1088.
4.2.17. 6-(1-Hydroxycyclohexyl)hepta-2,6-dien-4-ynyl
acetate
(126 MHz, CDCl3)
d
170.9, 170.6, 142.9, 136.4, 136.1, 135.8, 120.4,
(8qþ8q0). Yellow oil, 1H NMR (501 MHz, CDCl3) 8q:
d
6.18 (td, J¼6.1,
120.1, 113.2, 112.9, 93.6, 92.5, 88.8, 88.4, 86.5, 70.3, 63.9, 62.2, 22.54,
22.51, 20.86, 20.8; HRMS (EI) calcd for C11H14O3 [M]þ: 194.0943,
found 194.0962.
15.9 Hz, 1H), 5.90 (d, J¼6.1, 15.9 Hz, 1H), 5.63 (s, 1H), 5.45 (s, 1H), 4.62
(d, J¼4.8 Hz, 2H), 2.08 (s, 3H), 1.86e1.75 (m, 4H), 1.71e1.49 (m, 6H);
8q0:
d
6.02 (td, J¼6.7, 10.8 Hz, 1H), 5.83 (d, J¼10.8 Hz, 1H), 5.65 (s, 1H),
5.47 (s, 1H), 4.84 (d, J¼6.7 Hz, 2H), 2.08 (s, 3H), 1.86e1.75 (m, 4H),
4.2.13. 6-Methylene-7-(trimethylsilyloxy)oct-2-en-4-ynyl acetate
1.71e1.49 (m, 6H); 13C NMR (126 MHz, CDCl3)
d
170.7, 145.6, 140.0,
(8mþ8m0). Pale yellow oil, 1H NMR (501 MHz, CDCl3)
d
6.17 (8m,
136.3, 135.8,125.5,119.7, 119.5,113.4,113.1, 95.2, 94.7, 89.5, 86.4, 63.9,
62.2, 39.9, 36.3, 30.3, 29.7, 25.3, 25.1, 23.3, 21.8, 20.9, 20.5; HRMS (EI)
calcd for C15H20O3 [M]þ: 248.1413, found 248.1418.
td, J¼6.0, 15.8 Hz, 1H), 6.00 (8m0, td, J¼6.6, 10.8 Hz, 1H), 5.88 (8m,
d, J¼15.8 Hz, 1H), 5.81 (8m0, d, J¼10.8 Hz, 1H), 5.57 (8m0, s, 1H),
5.55 (8m, s, 1H), 5.42 (8m0, s, 1H), 5.39 (8m, s, 1H), 4.84 (8m0, d,
J¼6.6 Hz, 2H), 4.62 (8m, d, J¼6.0 Hz, 2H), 4.32e4.24 (8mþ8m0, m,
2H), 2.07 (8mþ8m0, s, 6H), 1.35e1.30 (8mþ8m0, s, 6H), 0.13
4.2.18. (E)-tert-Butyldimethyl(6-methylene-9-(p-tolyloxy)non-7-en-
4-ynyloxy)silane (10a) and tert-butyldimethyl(4-methylene-9-(p-
tolyloxy)non-7-en-5-ynyloxy)silane (11aþ11a0). Pale yellow oil, 1H
(8mþ8m0, s, 18H); 13C NMR (126 MHz, CDCl3)
d 170.8, 170.5, 136.2,
135.9, 135.8, 128.6, 128.1, 126.6, 120.0, 119.8, 113.5, 112.9, 94.5, 89.4,
88.3, 86.0, 70.4, 63.1, 62.3, 23.8, 23.7, 20.9, 0.01; HRMS (EI) calcd
for C14H21O3Si [MꢁH]þ: 266.1330, found 266.1337.
NMR (501 MHz, CDCl3)
d
7.14e7.08 (10aþ11aþ11a0, m, 6H),
6.88e6.82 (10aþ11aþ11a0, m, 6H), 6.40 (10a, d, J¼15.5 Hz, 1H),
6.36e6.27 (10aþ11a, m, 2H), 6.15 (11a0, td, J¼6.2, 11.0 Hz, 1H), 5.99
(11a, d, J¼15.9 Hz, 1H), 5.84 (11a0, d, J¼10.9 Hz, 1H), 5.47 (10a, s, 1H),
5.41 (11a0, s, 1H), 5.39 (10a, s, 1H), 5.37 (11a, s, 1H), 5.33 (11a0, s, 1H),
5.31 (11a, s, 1H), 4.83 (11a0, dd, J¼1.6, 6.2 Hz, 2H), 4.62 (11a, d,
4.2.14. (E)-7-(tert-Butyldimethylsilyloxy)-4-methyleneoct-2-en-5-
ynyl acetate (7n) and 7-(tert-butyldimethylsilyloxy)-6-methylene-

9110
K.-P. Wang et al. / Tetrahedron 69 (2013) 9105e9110
J¼4.9 Hz, 2H), 4.59 (11a, dd, J¼1.8, 5.3 Hz, 2H), 3.76 (11a0, t, J¼6.0 Hz,
2H), 3.71 (11a, t, J¼5.9 Hz, 2H), 3.66 (10a, t, J¼6.3 Hz, 2H), 2.50 (11a0,
t, J¼7.1 Hz, 2H), 2.39 (11a, t, J¼7.0 Hz, 2H), 2.32 (10aþ11aþ11a0, s,
9H), 2.32e2.29 (10a, m, 2H), 1.86e1.72 (10aþ11aþ11a0, m, 6H),
0.99e0.90 (10aþ11aþ11a0, m, 27H), 0.14e0.04 (10aþ11aþ11a0, m,
18H); HRMS (EI) calcd for C23H34O4SSi [M]þ: 434.1947, found
434.1955.
Supplementary data
Supplementary data related to this article can be found at http://
dx.doi.org/10.1016/j.tet.2013.08.024.
References and notes
1. For review of enyne metathesis: (a) Mori, M. Top. Organomet. Chem. 1998, 1, 133;
(b) Poulsen, C. S.; Madsen, R. Synthesis 2003, 1, 1; (c) Mori, M. In Handbook of
Metathesis; Grubbs, R. H., Ed.; Wiley-VCH: Weinheim, Germany, 2003; Vol. 2,
pp 176e204; (d) Giessert, A. J.; Diver, S. T. Chem. Rev. 2004, 104, 1317.
2. For overviews of enyne ring-closing metathesis and its application in natural
product synthesis: (a) Maifeld, S. V.; Lee, D. Chem.dEur. J. 2005, 11, 6118; (b)
Villar, H.; Fringsa, M.; Bolm, C. Chem. Soc. Rev. 2007, 36, 55; (c) Mori, M. Ma-
terials 2010, 3, 2087 For leading references: (d) Guo, H.; Madhushaw, R. J.; Shen,
F.-M.; Liu, R. Tetrahedron 2002, 58, 5627; (e) Tomita, T.; Kita, Y.; Kitamura, T.;
Sato, Y.; Mori, M. Tetrahedron 2006, 62, 10518; (f) Kim, B. G.; Snapper, M. L. J. Am.
Chem. Soc. 2006, 128, 52; (g) Ben-Othman, R.; Othman, M.; Coste, S.; Decroix, B.
Tetrahedron 2008, 64, 559; (h) Takahashi, H.; Yoshida, K.; Yanagisawa, A. J. Org.
Chem. 2009, 74, 3632; (i) Harvey, J. S.; Giuffredi, G. T.; Gouverneur, V. Org. Lett.
2010, 12, 1236; (j) Betkekar, V. V.; Panda, S.; Kaliappan, K. P. Org. Lett. 2012, 14,
198; (k) Chang, L.; Jiang, H.; Fu, J.; Liu, B.; Li, C.-C.; Yang, Z. J. Org. Chem. 2012, 77,
3609; (l) Wei, H.; Qiao, C.; Liu, G.; Yang, Z.; Li, C.-C. Angew. Chem., Int. Ed. 2013,
52, 620.
4.2.19. (E)-9-(tert-Butyldimethylsilyloxy)-4-methylenenon-2-en-5-
ynyl pivalate (10b) and 9-(tert-butyldimethylsilyloxy)-6-
methylenenon-2-en-4-ynyl pivalate (11bþ11b0). Yellow oil, 1H
NMR (501 MHz, CDCl3)
d
6.25 (11b, d, J¼15.3 Hz, 2H), 6.18e6.09
(10bþ11b, m, 2H), 5.96 (11b0, td, J¼6.5, 11.1 Hz, 1H), 5.84 (11b, d,
J¼15.9, 1H), 5.76 (11b0, d, J¼10.8 Hz, 1H), 5.42 (10b, s, 1H), 5.35 (10b,
s,1H), 5.34 (11b0, s,1H), 5.32 (11b, s,1H), 5.27 (11b0, s,1H), 5.25 (11b,
s, 1H), 4.80 (11b0, d, J¼6.5 Hz, 1H), 4.63 (10b, d, J¼5.8 Hz, 1H), 4.59
(11b, d, J¼5.8 Hz,1H), 3.73e3.60 (10bþ11bþ11b0, m, 6H), 2.48e2.60
(10bþ11bþ11b0, m, 6H), 1.80e1.69 (10bþ11bþ11b0, m, 6H), 1.29
(10bþ11bþ11b0, s, 9H), 1.21 (10bþ11bþ11b0, s, 9H), 1.20
(10bþ11bþ11b0, s, 9H), 0.88 (10bþ11bþ11b0, s, 27H), 0.05e0.03
(10bþ11bþ11b0, m, 18H); HRMS (EI) calcd for C21H36O3Si [M]þ:
364.2434, found 364.2629.
3. A review on cross metathesis: (a) Connon, S. J.; Blechert, S. Angew. Chem., Int.
Ed. 2003, 42, 1900.
4. Leading references for enyne cross metathesis: (a) Kinoshita, A.; Sakakibara, N.;
Mori, M. Tetrahedron 1999, 55, 8155; (b) Rodríguez-Conesa, S.; Candal, P.;
ꢁ
Jimenez, C.; Rodríguez, J. Tetrahedron Lett. 2001, 42, 6699; (c) Kotha, S.; Halder,
4.2.20. (E)-tert-Butyldimethyl(6-methylene-9-(trimethylsilyl)-non-7-
en-4-ynyloxy)silane (10d) and tert-butyldimethyl(4-methylene-9-(tri-
methylsilyl)non-7-en-5-ynyloxy)silane (11dþ11d0). Colorless oil, 1H
S.; Brahmachary, E. Tetrahedron 2002, 58, 9203; (d) Chatterjee, A. K.; Choi, T.-L.;
Sanders, D. P.; Grubbs, R. H. J. Am. Chem. Soc. 2003, 125, 11360 and references
therein; (e) Galan, B. R.; Giessert, A. J.; Keister, J. B.; Diver, S. T. J. Am. Chem. Soc.
2005, 127, 5762; (f) Giessert, A. J.; Diver, S. T. Org. Lett. 2005, 7, 351; (g) Mix, S.;
Blechert, S. Org. Lett. 2005, 7, 2015; (h) Middleton, M. D.; Peppers, B. P.; Diver, S.
T. Tetrahedron 2006, 62, 10528; (i) Clark, D. A.; Kulkarni, A. A.; Kalbarczyk, K.;
Schertzer, B.; Diver, S. T. J. Am. Chem. Soc. 2006, 128, 15632; (j) Clark, D. A.;
Basile, B. S.; Karnofel, W. S.; Diver, S. T. Org. Lett. 2008, 10, 4927; (k) Murelli, R.
NMR (501 MHz, CDCl3)
d
6.20e6.06 (10dþ11d, m, 2H), 5.97 (11d0, dd,
J¼8.8, 19.3 Hz,1H), 5.45 (11d0, d, J¼10.6 Hz, 1H), 5.42 (11d, J¼15.7 Hz,
1H), 5.27 (11d0, s,1H), 5.263 (10d, s,1H), 5.261 (11d, s,1H), 5.20 (11d0,
s, 1H), 5.18 (11d, s, 1H), 5.14 (10d, s, 1H), 3.73 (10d, t, J¼6.1 Hz, 2H),
3.63 (11dþ11d0, t, J¼6.3 Hz, 4H), 2.45 (10d, t, J¼7.0 Hz, 2H), 2.27e2.20
(11dþ11d0, m, 4H), 1.85 (11d0, d, J¼8.8 Hz, 2H), 1.81e1.72
(10dþ11dþ11d0, m, 6H), 1.61 (11d, d, J¼8.3 Hz, 1H), 1.58 (10d, d,
J¼8.4 Hz, 1H), 0.90 (10dþ11dþ11d0, s, 37H), 0.07e0.01
ꢁ
P.; Catalan, S.; Gannon, M. P.; Snapper, M. L. Tetrahedron Lett. 2008, 49, 5714; (l)
Kalbarczyk, K. P.; Diver, S. T. J. Org. Chem. 2009, 74, 2193; (m) Kotha, S.; Bansal,
D.; Singh, K.; Banerjee, S. J. Organomet. Chem. 2011, 696, 1856; (n) Kotha, S.;
Waghule, G. T. J. Org. Chem. 2012, 77, 6314.
5. Computational studies of enyne metathesis mechanism: (a) Lippstreu, J. J.;
Straub, B. F. J. Am. Chem. Soc. 2005, 127, 7444; (b) NuC¸ ez-Zarur, F.; Solans-
Monfort, X.; Rodrguez-Santiago, L.; Pleixats. Chem.dEur. J. 2011, 17, 7506.
6. (a) Kim, M.; Miller, R. L.; Lee, D. J. Am. Chem. Soc. 2005, 127, 12818; (b) Kim, M.;
Lee, D. Org. Lett. 2005, 7, 1865; (c) Wang, K.-P.; Yun, S. Y.; Lee, D.; Wink, D. J. J.
Am. Chem. Soc. 2009, 131, 15114; (d) Yun, S. Y.; Wang, K.-P.; Kim, M.; Lee, D. J. Am.
Chem. Soc. 2010, 132, 8840.
7. (a) Cho, E. J.; Lee, D. Org. Lett. 2008, 10, 257; (b) Li, J.; Park, S.; Miller, R. L.; Lee, D.
Org. Lett. 2009, 11, 571; (c) Li, J.; Lee, D. Chem.dAsian J. 2010, 5, 1298.
8. Scholl, M.; Ding, S.; Lee, C. W.; Grubbs, R. H. Org. Lett. 1999, 1, 953.
9. A review on metallotropic shift: Kim, M.; Lee, D. Org. Biomol. Chem. 2007, 5,
3418.
10. (a) van Otterlo, W. A. L.; Ngidi, E. L.; de Koning, C. B.; Fernandes, M. A. Tetra-
hedron Lett. 2004, 45, 659; (b) Kim, M.; Lee, D. J. Am. Chem. Soc. 2005, 127, 18024.
11. Trnka, T. M.; Day, M. W.; Grubbs, R. H. Organometallics 2001, 20, 3845.
12. (a) Yun, S. Y.; Kim, M.; Lee, D. J. Am. Chem. Soc. 2009, 131, 24.
13. Marino, J. P.; Nguyen, H. N. J. Org. Chem. 2002, 67, 6841.
(10dþ11dþ11d0, m, 18H); 13C NMR (126 MHz, CDCl3)
d 142.1, 141.1,
131.9, 131.73, 131.67, 130.3, 128.5, 120.1, 118.5, 107.4, 106.2, 93.8, 91.3,
89.0, 87.4, 87.0, 78.2, 62.3, 62.2, 61.6, 33.73, 33.68, 31.9, 31.3, 26.0,
24.9, 23.30, 22.96, 18.3, 15.7, ꢁ1.62, ꢁ1.88, ꢁ1.91, ꢁ5.31; HRMS (EI)
calcd for C19H36OSi2 [M]þ: 336.2305, found 336.2298.
4.2.21. tert-Butyldimethyl(6-methyleneoct-7-en-4-ynyloxy)-silane
(10e). Yellow oil, 1H NMR (501 MHz, CDCl3)
d
6.35 (dd, J¼10.1,
17.0 Hz, 1H), 5.62 (d, J¼17.0 Hz,1H), 5.44 (s, 1H), 5.35 (s, 1H), 5.22 (d,
J¼10.1 Hz, 1H), 3.68 (t, J¼5.9 Hz, 2H), 2.46 (t, J¼7.1 Hz, 2H), 1.73 (m,
2H), 0.90 (s, 9H), 0.06 (s, 6H); 13C NMR (126 MHz, CDCl3)
d 138.2,
136.6, 122.7, 117.4, 64.4, 61.6, 61.3, 31.8, 25.9, 1.02, ꢁ5.33; HRMS (EI)
calcd for C15H26OSi [M]þ: 250.1753, found 250.1757.
14. (a) Hansen, E. C.; Lee, D. Org. Lett. 2004, 6, 2035.
15. Effect of ethylene in enyne metathesis: (a) Mori, M.; Sakakibara, N.; Kinoshita,
A. J. Org. Chem. 1998, 63, 6082; (b) Giessert, A. J.; Brazis, N. J.; Diver, S. T. Org.
Lett. 2003, 5, 3819; (c) Hansen, E. C.; Lee, D. J. Am. Chem. Soc. 2004, 126, 15074;
(d) Grotevendt, A. G. D.; Lummiss, J. A. M.; Mastronardi, M. L.; Fogg, D. E. J. Am.
Chem. Soc. 2011, 133, 15918.
Acknowledgements
We are grateful to the University of Illinois at Chicago for the
16. Lee, H.-Y.; Kim, B. G.; Snapper, M. L. Org. Lett. 2003, 5, 1855.
financial support.
17. Adjiman, C. S.; Clarke, A. J.; Copper, G.; Taylor, P. C. Chem. Commun. 2008, 2806.