Synthesis of chiral ADMET polymers containing repeating D-chiro-inositol units derived from a biocatalytically prepared diene diol

Article abstract of DOI:10.1016/j.tet.2003.10.097

Several chiral hydroxylated polymers have been prepared, via ADMET techniques, from the diene diol derived from bromobenzene, obtained by means of whole-cell fermentation with Escherichia coli (JM109 pDTG601).

Full text of DOI:10.1016/j.tet.2003.10.097

Tetrahedron 60 (2004) 641–646
Synthesis of chiral ADMET polymers containing repeating
D-chiro-inositol units derived from a biocatalytically
prepared diene diol
*
Vu P. Bui and Tomas Hudlicky
Department of Chemistry, University of Florida, Gainesville, FL 32611-7200, USA
Received 20 June 2003; revised 13 August 2003; accepted 17 October 2003
Abstract—Several chiral hydroxylated polymers have been prepared, via ADMET techniques, from the diene diol derived from
bromobenzene, obtained by means of whole-cell fermentation with Escherichia coli (JM109 pDTG601).
q 2003 Elsevier Ltd. All rights reserved.
1
–3
28–31
Chiral polymers are used in a number of interesting
applications: in catalysis for asymmetric induction in
we have demonstrated previously.
It is also possible to
approach the monomer synthesis from protected synthons—
in such cases the number of isomeric possibilities in
intermediates of this type would approach the theoretical
limit of 64. As described in recent papers on combinatorial
1
,2,4
5
organic synthesis,
in chiral separations, and in ferro-
6
electric and nonlinear optical applications. Achiral mono-
mers can be induced to form polymers with a helical
conformation by means of ‘helix-sense-selective’ polymeri-
zation with either a chiral initiator or catalyst. These
include poly(chloral), poly(isocyanates), poly(isocyanides),
and poly(triarylmethylmethacrylates). Other polymers,
3
2,33
possibilities of oligoinositols,
the number of possible
3
isomers increases exponentially with higher oligomers once
secondary and tertiary structures develop through hydrogen-
bonded forms and b-turns initiated by the 1,2 trans
7
29–31,34
obtained, for example, by cyclopolymerization of diolefins,
9 – 12
connectivity in 3.
We were interested primarily in
8
1,2,11,12
diisocyanides, vinyl ethers,
1
bis(styrenes),
17
and diepoxides, derive their optical
generating relatively low molecular weight polymers and
investigating physical and chemical properties of these
compounds in anticipation of further cross-linking and
testing of these compounds as materials for chiral
separations.
3–16
dimethyacylates,
activity from chirality in the main chain or in side chains.
Synthetic peptide-like polymers are also included in this
The introduction of metal catalysts by Ziegler
and Natta in the late 1940s provided an approach to making
chiral polymers on an industrial scale.
methods for the preparation chiral polymers remains a
challenging field, as radical, anionic, and cationic methods
1
8,19
group.
2
0,21
Development of
To test our approach to this problem, bis-allyl ether 8,
Scheme 2, was prepared and subjected to polymerization
with Grubbs’ first-generation catalyst. The bis-ether was
generated by first protecting the cis-diol of the diene diol 2
as the acetonide followed by epoxidation of the more
electron-rich double bond to afford epoxide 4. The
BF ·Et O-catalyzed epoxide opening of epoxide 4 with
2
2–24
are generally neither stereo- nor enantioselective.
We have become interested in polyhydroxylated polymers,
or high oligomers, such as 3, derived from the monomers of
established configuration via acyclic diene metathesis
ADMET) of vicinally bis-alkylated olefinic side chains.
The corresponding monomers are easily obtained from
3
2
allyl alcohol led to a low yield of ether 5 at the expense of
2
5,26
(
diene diol 2, the product of the whole-cell fermentation of
2
7
bromobenzene with a E. coli JM109 pDTG601A, recom-
binant organism expressing toluene dioxygenase (TDO),
Scheme 1. The central inositol unit can readily be
synthesized in any of the nine possible configurations, as
*
Corresponding author at present address: Department of Chemistry,
Brock University, St Catharines, Ontario L2S 3A1, Canada;
e-mail address: thudlicky@brocku.ca
Scheme 1. Chemoenzymatic approach to polyhydroxylated chiral polymers
(D-chiro-inositol configuration shown).
0040–4020/$ - see front matter q 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2003.10.097

642
V. P. Bui, T. Hudlicky / Tetrahedron 60 (2004) 641–646
2 2 3 2
Scheme 2. Synthesis of monomer bis-allyl ether 8. Key: (i) DMP, pTsOH; (ii) mCPBA, CH Cl ; (iii) BF ·Et O, allyl alcohol; (iv) Amberlyst resin; (v) DMF;
NaH, allyl bromide.
generating the conduritol dimer 6. The problem was
circumvented by treating epoxide 4 first with Amberlyst
resin to afford trans diol 7, which was alkylated with
allylbromide to afford allyl ether 8 in 98% yield (Scheme 2).
and a mixture of de-allylated products 5 and 10, along with
starting material, was isolated.
Diol 7 was alkylated with 5-bromopentene to furnish bis-
alkylated ether 11, which polymerized with Grubbs’ first-
generation catalyst. The result was polymer 12 having an
estimated molecular weight of 4600. When monomer 11
was polymerized with Grubbs’ second-generation catalyst, a
polymer with an average molecular weight of 20,000 was
obtained, determined by light-scattering (LS) analysis
Allyl ether 8 was subjected to ADMET conditions with
Grubbs’ first-generation catalyst under several conditions.
In dilute methylene chloride, no polymerization occurred,
and only the cyclic dioxocane 9 formed (Scheme 3). When
the reaction was conducted neat, again no polymer formed,
(Scheme 4).
The synthesis of the fully hydroxylated polymer was carried
out as outlined in Scheme 5.
In theapproachtopolyhydroxylatedpolymer18, thecisdiolin
2
was protected, and the more electron rich double bond was
converted to cis diol 13. Reduction under radical conditions
with tri-n-butyltinhydride and subsequent epoxidation with
mCPBA followed by protection of the cis diol provided
epoxide 14. BF ·Et O-catalyzed epoxide opening with
3
2
4
5
-penten-1-ol gave alcohol 15, which was alkylated with
-bromopentene to furnish the desired monomer 16. Exposure
of this material to Grubbs’ first generation of catalyst (neat)
gave polymer 17 whose deprotection under acidic condition
gave the fully hydroxylated polymer 18, with a molecular
weight estimated at ,10,000 via GPC analysis, as a viscous
oil. Light scattering analysis of polymer 18 estimated the
average molecular weight of the polymer at 18,000.
Scheme 3. Polymerization of 8 with Grubbs’ first-generation catalyst.
Scheme 4. Preparation and polymerization of pentenyl ether 11. Key: (i) 5-bromopentene, DMF, NaH; (ii) Grubbs’ catalyst (1st generation), neat, or Grubbs’
catalyst (2nd generation), neat.

V. P. Bui, T. Hudlicky / Tetrahedron 60 (2004) 641–646
643
Scheme 5. Approach to fully hydroxylated chiral polymers. Key: (i) DMP, pTsOH; (ii) acetone, H
CH Cl ; (v) BF ·Et O, CH Cl , 4-penten-1-ol; (vi) DMF, NaH, 5-bromopentene; (vii) Grubbs’ first-generation catalyst; (viii) THF–TFA–H O, 4:1:1.
2
O, NMO, OsO
4
; (iii) Bu
3
SnH, AIBN, PhH; (iv) mCPBA,
2
2
3
2
2
2
2
1. Conclusions
2.1.1. 5-(5-Allyloxy-7-bromo-2,2-dimethyl-3a,4,5,7a-tet-
rahydro-benzo[1,3]dioxol-4-yloxy)-7-bromo-2,2-
dimethyl-3a,4,5,7a-tetrahydro-benzo[1,3]dioxol-4-ol (6).
Bromoepoxide 4 (0.5 g) was added to a flame-dried 50 mL
round-bottomed flask containing a stirred solution of allyl
alcohol (0.56 g, 9.66 mmol) in freshly distilled methylene
chloride (5 mL) under argon atmosphere. The reaction
mixture was cooled to 278 8C for 20 min. BF ·Et O
New homochiral polymeric materials have been prepared
from metabolites of type 2. Further exploitation of the
properties of these hydroxylated polymers in the area of
chiral separation and catalyst development are ongoing and
will be reported in due course.
3
2
(10 mol%) was added, and the reaction mixture was stirred
overnight. The reaction was quenched with water (10 mL),
and the mixture was extracted with methylene chloride
2
. Experimental
(
3£10 mL). The organic layers were combined and washed
2
.1. General
with 5% NaHCO (10 mL), dried (MgSO ) and concen-
3
4
trated under reduced pressure to afford a reddish residue.
The products were purified by flash chromatography
(hexanes–EtOAc, 4:1) to yield dimer 6 as a white solid
(356 mg, 63%) with trace amount of alcohol 5 (8 mg, 3%).
All commercial chemicals and solvents are reagent grade
and were used without further purification unless otherwise
specified. Standard techniques for the exclusion of moisture
were used in all reactions. Reactions were monitored by
thin-layer chromatography on 0.25 mm silica gel plates
2.1.2. 5-Allyloxy-7-bromo-2,2-dimethyl-3a,4,5,7a-tetra-
hydro-benzo[1,3]dioxol-4-ol (5). R ¼0.48 (hexanes–
(
60F-254, Silicycle) and visualized with UV light, iodine
f
1
vapors, or 5% phosphomolybdic acid in 95% ethanol. Final
compounds were typically purified by flash chromatography
EtOAc, 3:1); H NMR (300 MHz, CDCl ) d 6.22 (m, 2H),
3
5.28 (ddd, J¼17.2, 1.75, 1.46 Hz, 1H), 5.16 (ddd, J¼10.5,
1.75, 1.46 Hz, 1H), 4.94 (bs, 1H), 4.70 (ddd, J¼6.42, 1.75,
1.46 Hz, 1H), 4.25 (ddt, J¼13.1, 5.26, 1.46 Hz, 1H), 4.16
(dd, J¼9.64, 6.42 Hz, 1H), 3.98 (ddt, J¼12.8, 5.84, 1.46 Hz,
1H), 3.60 (t, J¼9.64 Hz, 1H), 1.55 (s, 3H), 1.43 (s, 3H).
1
13
on silica gel (230–400 mesh). All H- and C NMR spectra
were recorded at 300 and 75 MHz, respectively, using a
Varian 300 spectrometer. Chemical shifts are reported
relative to TMS, CDCl , or DMSO-d . Coupling constants
3
6
are measured in Hz. Infrared spectra, recorded on a Perkin–
2
1
Elmer FT-IR, are reported as wavenumbers (cm ). High-
resolution mass spectra were performed at the University of
Florida, elemental analyses at Atlantic Microlab, Inc.
Optical rotations were recorded on a Perkin–Elmer 241
Compound 6: R ¼0.65 (hexanes–EtOAc, 3:2); mp¼176–
f
3
1
177 8C; [a] ¼þ47.35 (c, 0.665, CHCl ); IR (KBr) 3498,
D
3
2981, 1645, 1457, 1381, 1214, 1046, 998, 870, 513 cm2 ; H
1 1
NMR (300 MHz, CDCl ) d 6.33 (d, J¼1.71 Hz, 1H), 6.28 (d,
3
2
1
2
21
digital polarimeter (10 deg cm g ). Melting points
were obtained on a Thomas–Hoover capillary melting
point apparatus and are uncorrected. Gel permeation
chromatography (GPC) was performed on two 300 mm
Polymer Laboratories 5 mm mixed-C columns with a Rainin
SD-300 pump, a Hewlett–Packard 1047-A RI detector, a
TC-45 Eppendorf column heater set to 35 8C and a Waters
U6K injector.
J¼1.71 Hz, 1H), 6.18–5.85 (m, 1H), 5.39–5.24 (m, 2H), 4.72
(d, J¼6.84 Hz, 1H), 4.47 (d, J¼6.84 Hz, 1H), 4.46 (s, 1H),
4.28–4.12 (m, 3H), 4.45–4.00 (m, 1H), 3.90 (d, J¼8.30 Hz,
1H), 3.86–3.80 (m, 1H), 3.67 (m, 1H), 3.53 (t, J¼8.7 Hz, 1H),
1
3
1.58 (s, 3H), 1.57 (s, 3H), 1.42 (s, 3H), 1.41 (s, 3H); C NMR
(75 MHz, CDCl ) d 135.1, 133.5, 132.8, 118.8, 118.1, 117.9,
3
111.5, 111.1, 84.4, 84,1, 78.7, 77.6, 77.20, 77.1, 74.1, 74.0,
71.2, 28.2, 27.7, 25.9, 25.7. HRMS (FAB) calcd for

644
V. P. Bui, T. Hudlicky / Tetrahedron 60 (2004) 641–646
C H O Br : 551.0280. Found: 551.0045. Anal. calcd for
2
22 mmol) dissolved in DMF (10 mL) was then added
dropwise, and the reaction mixture was stirred for 6 h. The
reaction was quenched with water (5 mL) and extracted
with diethyl ether (3£25 mL). The ethereal extracts were
1
29
7
2
C H O Br : C, 45.67; H, 5.11. Found: C, 45.92; H, 5.28.
2
1
28
7
2
2
.1.3. 4,5-bis-Allyloxy-7-bromo-2,2-dimethyl-3a,4,5,7a-
tetrahydro-benzo[1,3]dioxole (8). Into a 50 mL oven-
dried round-bottomed flask, NaH (2.41 g, 45 mmol) was
suspended in anhydrous DMF (20 mL) under argon
atmosphere. Bromodiol 7 (2.41 g, 9.1 mmol) was added,
and the reaction mixture was stirred for 1 h at room
temperature. Allylbromide (5.46 g, 45 mmol) dissolved in
combined, dried (MgSO ), and concentrated. The residue
4
was purified by flash chromatography (hexanes–EtOAc,
9:1). Fractions containing monomer 11 were combined and
concentrated to yield a yellowish oil, which was distilled
under reduced pressure (155 8C, 0.2 mm Hg) using a
Kugelrohr apparatus to furnish monomer 11 as a colorless
1
1
0 mL DMF was added dropwise to the reaction mixture.
oil (0.35 g, 32%). H NMR (300 MHz, CDCl ) d 6.2 (d,
3
The reaction proceeded for 8 h after the addition of
allylbromide. The reaction was quenched with water, and
the mixture was extracted with diethyl ether (3£25 mL).
The product was purified by flash chromatography (hex-
anes–EtOAc, 9:1). The fractions containing bis-allylether 8
were combined and concentrated to yield a yellowish oil,
which was further purified by distillation at high tempera-
ture at under reduced pressure (150 8C, 0.2 mm Hg) using a
Kugelrohr apparatus to afford bis-allylether 8 as a colorless
J¼3.05 Hz), 5.92–5.74 (m, 2H), 5.05 (J¼2.05, 1.54 Hz,
1H), 5.03–4.92 (m, 3H), 4.63 (dd, J¼1.03, 6.41 Hz, 1H),
4.21–4.12 (dd, J¼6.41, 8.46 Hz, 1H), 3.86–3.67 (m, 3H),
3.65–3.51 (m, J¼2.56, 5.64, 6.41, 6.67 Hz, 2H), 3.39 (t,
J¼8.1 Hz), 2.20–2.08 (m, 4H), 1.77–1.63 (m, 4H), 1.54 (s,
1
3
3H), 1.41 (s, 3H); C NMR (75 MHz, CDCl ) d 138.5,
3
138.2, 133.8, 118.8, 115.2, 114.8, 110.7, 80.0, 79.0, 78.0,
77.5, 72.3, 70.0, 30.4, 30.8, 29.5, 29.3, 28.3, 26.3; HRMS
(EI) m/z calcd for C H O Br: 400.1249 Found: 400.1256.
1
9 29 4
oil (3.14 g, 98%). R ¼0.44 (hexanes–EtOAc, 6:1);
f
2
7
[
a] ¼36.85 (c 1.1, CDCl ); IR (film) 3078, 2987, 1646,
2.1.6. ADMET polymerization of monomer 11. Freshly
distilled monomer 11 (1.68 g, 4.19 mmol) was placed in a
10 mL round-bottomed flask equipped with a magnetic stir
bar. The monomer was degassed by means of freeze-pump-
thaw cycles under high vacuum (,102 Torr). Grubbs’
second-generation catalyst (35 mg, 1%) was then added
D
3
2
1 1
1
456, 1381, 1246, 1218, 1073, 869, 794 cm ; H NMR
(
(
1
6
8
1
300 MHz, CDCl ) d 6.21 (d, J¼2.19 Hz, 1H), 6.02–5.84
3
m, 2H), 5.33 (dt, J¼1.47, 1.71 Hz, 1H), 5.28 (dt, J¼1.47,
4
.71 Hz, 1H), 5.24–5.14 (m, 2H), 4.65 (dd, J¼1.22,
.35 Hz, 1H), 4.40–4.25 (m, 2H), 4.24–4.19 (dd, J¼6.35,
.55 Hz, 1H), 4.16 (t, J¼1.46 Hz, 1H), 4.14 (t, J¼1.46 Hz,
H), 3.90–3.84 (ddd, J¼1.22, 0.98, 7.82 Hz, 1H), 3.52 (t,
under argon atmosphere. A few drops of dry CDCl were
3
added to initiate the polymerization process. After the
addition of the catalyst, very slow to moderate bubbling of
ethylene was observed. The bubbling reaction mixture was
then exposed to intermittent vacuum until the viscosity
increased, followed by exposure to high vacuum to remove
ethylene, which is continuously generated during the course
of the polymerization. The reaction was carried out at room
temperature until increased viscosity prevented stirring,
after which time the temperature was raised to 55 8C over a
period of 5 days until a very high viscosity was obtained or
bubbling ceased. The reaction mixture was then cooled to
room temperature, and the reaction quenched by exposure to
air. The viscous residue was dissolved in ethyl acetate and
passed through a short column of silica to furnish a brown
viscous oil (1.58 g), whose average molecular weight was
estimated to be 20,000 by light-scattering analysis.
1
3
J¼8.05 Hz, 1H), 1.55 (s, 3H), 1.41 (s, 3H); C NMR
(
75 MHz, CDCl ) d 135.2, 134.5, 133.6, 119.0, 117.4,
3
1
HRMS (EI) m/z calcd for C H O Br [M2CH ] :
17.4, 110.8, 79.2, 78.0, 77.9, 77.65, 73.5, 71.7, 28.2, 26.3;
þ
1
4
18
4
3
329.0388. Found: 329.0271. Anal. calcd for C H O Br:
15 21 4
C, 52.19; H, 6.13. Found C, 52.35; H, 6.23.
2
.1.4. ADMET polymerization of bis-allylether 8: 4-
bromo-2,2-dimethyl-3a,5a,7,10,11a,11b-hexahydro-
,3,6,11-tetraoxa-cycloocta[e]indene (9). Into an oven-
dried 10 mL round-bottomed flask, bis-allylether 8 (76 mg,
.2 mmol) was dissolved in freshly distilled methylene
1
0
chloride (5 mL) at room temperature under argon atmo-
sphere. Grubbs’ first-generation catalyst (9.4 mg,
0
.01 mmol) was then added, and the reaction mixture was
2
7
stirred under argon for 24 h. The reaction was quenched
with ethyl vinyl ether (0.2 mL), and the mixture concen-
trated under reduced pressure. The residue was purified via
flash chromatography to yield the cyclic dioxocane 9 as a
[a] ¼212.1 (c 1.1, CH OH).
D
3
2.1.7. 2,2,7,7-Tetramethyl-5-pent-4-enyloxy-hexahydro-
benzo[1,2-d;3,4-d ]bis[1,3]dioxol-4-ol (15). The diaceto-
0
colorless oil (25 mg, 36%). R ¼0.45 (hexanes–EtOAc, 4:1);
nide-protected epoxide 14 (1.0 g, 4.13 mmol) and 4-penten-
1-ol (0.64 mL, 6.19 mmol) were dissolved in freshly
distilled methylene chloride (15 mL), and the mixture
cooled in an ice bath for 15 min. BF ·Et O (10 mol%) was
f
1
H NMR (300 MHz, CDCl ) d 6.17 (d, J¼2.1 Hz), 5.85–
3
5
.65 (m, 2H), 4.70–5.58 (m, 2H), 4.46–4.25 (m, 3H), 4.17
(
dd, J¼6.4, 9.0 Hz, 1H), 3.91 (td, J¼8.47, 1.46 Hz, 1H),
3
2
1
3
3
NMR (75 MHz, CDCl ) d 134.9, 130.1, 129.1, 118.2, 111.0,
.47 (t, J¼8.76 Hz, 1H), 1.56 (s, 3H), 1.42 (s, 3H);
C
added, and the reaction was allowed to proceed overnight.
The reaction was quenched with water, and the mixture was
extracted with methylene chloride (3£25 mL). The organic
layers were combined, dried (Na SO ) and concentrated.
3
81.5, 78.8, 77.4, 77.3, 69.5, 67.4, 28.4, 26.1; HRMS (EI)
calcd for C H BrO : 316.0310. Found: 316.0309.
1
3
17
4
2
4
The product was purified by flash chromatography (hex-
anes–EtOAc, 5:1) to yield alcohol 15 (0.794 g, 59%) as a
2
3
.1.5. 7-Bromo-2,2-dimethyl-4,5-bis-pent-4-enyloxy-
a,4,5,7a-tetrahydro-benzo[1,3]dioxole (11). To a sol-
colorless semi-solid material. R ¼0.25 (hexane–EtOAc,
f
2
7
ution of bromodiol 7 (0.73 g, 2.75 mmol) in anhydrous
DMF (10 mL) cooled in an ice bath, NaH (0.66 g, 22 mmol)
was added under argon atmosphere. The reaction mixture
was allowed to stir for 1 h. 5-Bromopentene (3.28 g,
5:1), [a] ¼229.4 (c 1.1, CH OH); IR (film) 3459, 2986,
D
3
1 1
1380, 1260, 1067, 1025 cm2 ; H NMR (300 MHz, CDCl )
3
d 5.92–5.74 (m, 1H), 5.10–4.92 (m, 2H), 4.28–4.12 (m,
4H), 3.96–3.84 (m, 1H), 3.70–3.50 (m, 2H), 3.30–3.20 (m,

V. P. Bui, T. Hudlicky / Tetrahedron 60 (2004) 641–646
645
1
H), 2.93 (s, exchanged with D O, 1H), 2.22–2.10 (m, 2H),
2
weight was estimated at 10,000 via GPC analysis. Light
scattering analysis of polymer 18 estimated the average
molecular weight of the polymer to be at around 18,000.
1
.80–1.65 (m, 2H), 1.51 (s, 6H), 1.36 (s, 3H), 1.34 (s, 3H);
C NMR (75 MHz, CDCl ) d 138.42, 115.11, 110.3, 110.0,
1
3
3
2
7
8
2
[
0.0, 79.3, 78.5, 76.9, 76.8, 71.5, 70,9, 30.5, 29.2, 27.9,
[a] ¼25.1 (c 2.1, CH OH).
D
3
7.8, 25.4, 25.2; HRMS (EI) m/z calcd for C H O
6 25 6
1
þ
M2CH ] : 313.1651. Found: 313.1649.
3
Acknowledgements
2
hydro-benzo[1,2-d;3,4-d ]bis[1,3]dioxole (16). In
.1.8. 2,2,7,7-Tetramethyl-4,5-bis-pent-4-enyloxy-hexa-
a
0
We thank Timothy Hopkins and John C. Sworen for GPC
analysis and Brian Cuevas for light scattering analysis.
Financial support from the national Science Foundation
1
0 mL round-bottomed flask NaH (169 mg, 4.2 mmol)
was suspended in anhydrous DMF (5 mL). Alcohol 15
138 mg, 0.42 mmol) dissolved in DMF (5 mL) was then
(
(
CHE-9910412), TDC Research, Inc., TDC Research
added dropwise to the reaction flask and allowed to stir at
room temperature for 45 min. 5-Bromopentene (0.62 mL,
Foundation, and the donors of the Petroleum Research
Foundation administered by the American Chemical
Society (PRF-38075-AC) are gratefully acknowledged.
4.2 mmol) was then added, and the reaction was allowed to
proceed for 5 h. The reaction was quenched with H O
2
(
portions were combined, washed with saturated NaCl
5 mL) and extracted with Et O (3£10 mL). The ethereal
2
References and notes
(
The product was purified by flash chromatography (hex-
10 mL), H O (10 mL), dried (MgSO ), and concentrated.
2 4
1. Wulff, G. Angew. Chem., Int. Ed. Engl. 1989, 28, 21.
2. Wulff, G.; Krieger, S. Macromol. Chem. Phys. 1994, 195, 3665.
3. Okamoto, Y.; Nakano, T. Chem. Rev. 1995, 94, 349.
4. Rousch, W. R.; Hawkins, J. M.; Grubbs, R. H. Chemtract:
Org. Chem. 1988, 1, 21.
anes–EtOAc, 9:1) to yield a thick red oil (96 mg, 93%).
1
R ¼0.68 (hexane–EtOAc, 5:1), H NMR (300 MHz,
f
CDCl ) d 5.90–5.72 (m, 2H), 5.08–5.02 (m, 1H), 5.02–
3
4
3
1
.90 (m, 3H), 4.50–4.32 (m, 1H), 4.24–4.10 (m, 4H),
.80–3.66 (m, 4H), 3.36–3.26 (m, 2H), 2.20–2.06 (m, 4H),
.76–1.63 (m, 4H), 1.49 (s, 6H), 1.40 (s, 6H); C NMR
5. Okamoto, Y.; Hatada, K. Chromatographic Chiral Separ-
ations; Marcel Dekker: New York, 1988.
1
3
(
7
2
75 MHz, CDCl ) d 138.6, 114.8, 114.7, 112.3, 109.6, 80.3,
3
9.4, 77.3, 76.7, 75.6, 74.2, 71.7, 70.9, 30.4, 29.9, 29.5,
9.3, 28.0, 26.5, 25.6, 24.3.
6. Williams, D. J. Angew. Chem., Int. Ed. Engl. 1984, 23, 690.
7. Coates, G. W.; Waymouth, R. M. J. Am. Chem. Soc. 1993,
115, 91.
8
. Ito, Y.; Ihara, E.; Murakami, M. Angew. Chem., Int. Ed. Engl.
1992, 1509.
2
.1.9. ADMET polymerization of diene 16 to generate
polymer 17. Monomer 16 (240 mg, 0.61 mmol) was placed
in a 10 mL round-bottomed flask equipped with a stir bar
and was degassed through several freeze-pump-thaw cycles
9. Yokota, K.; Haba, O.; Satoh, T. Macromol. Chem. Phys. 1995,
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10. Yokota, K.; Kakuchi, T.; Yamanaka, M.; Takada, Y.
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11. Kakuchi, T.; Harada, Y.; Hashimoto, H.; Satoh, T.; Yokota, K.
J. Macromol. Sci., Pure Appl. Chem. 1994, A31, 751.
12. Kakuchi, T.; Kawai, H.; Katoh, S.; Haba, O.; Yokota, K.
Macromolecules 1992, 25, 5545.
4
under high vacuum (,10 Torr). Grubbs’ first-generation
catalyst (5 mg) was then added under argon atmosphere.
After the addition of Grubb’s catalyst, very slow to
moderate bubbling of ethylene was observed. The bubbling
reaction was then exposed to intermittent vacuum until the
viscosity increased, followed by exposure to high vacuum to
remove the ethylene, which was continuously generated
during the course of the polymerization. The reaction was
maintained at room temperature until the increase in
viscosity prevented stirring. At this point, the reaction
temperature was slowly raised to 45 8C over a period of 5
days until bubbling ceased. The reaction mixture was then
cooled to room temperature, and quenched by exposure to
air. The viscous residue was dissolved in ethyl acetate and
13. Kakuchi, T.; Haba, O.; Fukui, N.; Yokota, K. Macromolecules
1995, 28, 5941.
14. Haba, O.; Morimoto, Y.; Uesaka, T.; Yokota, K. Macromol-
ecules 1995, 28, 6378.
15. Nakano, T.; Okamoto, Y.; Sogah, D. Y.; Zheng, S.
Macromolecules 1995, 28, 8705.
16. Nakano, T.; Sogah, D. Y. J. Am. Chem. Soc. 1995, 117, 534.
17. Satoh, T.; Yokota, K.; Kakuchi, T. Macromolecules 1995, 28,
4762.
passed through a short column of silica to furnish polymer
18. Sando, F.; Endo, T. Macromol. Chem. Phys. 1999, 200, 2651.
19. Nakno, T. J. Chromatogr. 2001, 906, 205.
20. Crabtree, R. H. The Organometallic Chemistry of the
Transition Metals, 3rd ed.; Wiley: New York, 2001.
21. Eleuterio, H. S. US Patent 3 074 918, 1963..
1
1
5
3
6
7 as a brown viscous oil. H NMR (300 MHz, CDCl ) d
3
.50–5.40 (b, 2H), 4.25–4.15 (b, 4H), 3.80–3.65 (m, 4H),
.31 (s, 2H), 2.20–1.80 (b, 4H), 1.75–1.55 (m, 4H), 1.50 (s,
H), 1.33 (s, 6H).
2
2. Ebdon, J. R. New Methods Polym. Synth. 1991, 1–21.
2.1.10. Deprotection of polymer 17. Polymer 17 was
dissolved in 5 mL of a 4:1:1 mixture of THF, TFA and
23. Jagur-Grodzinski, J. J. Polym. Sci., Part A: Polym. Chem.
2002, 40, 2116–2133.
H O. The reaction was stirred at room temperature for 4 h.
2
24. Ray, W. H. Can. J. Chem. Engng 1991, 69, 626–629.
25. Hopkins, T. E.; Wagener, K. B. Adv. Mater. 2002, 14,
1703–1715.
The reaction mixture was diluted with brine (3 mL) and
extracted with ethyl acetate (4£10 mL). The organic
fractions were combined, dried (Na SO ), and concentrated.
2
4
26. Schwendeman, J. E.; Church, A. C.; Wagener, K. B. Adv.
Synth. Catal. 2002, 344, 597–613.
After the solvent was removed, the residue was introduced
onto a silica-gel column and eluted with ethyl acetate to
arrive at fully hydroxylated polymer 18, whose molecular
27. Zylstra, G. J.; Gibson, D. T. J. Biol. Chem. 1989, 264,
14940–14946.

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8. Hudlicky, T. Chem. Rev. 1996, 96, 3–30.
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K. A.; Hudlicky, T. J. Am. Chem. Soc. 2002, 124,
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32. Dolhaine, H.; H o¨ nig, H. Match 2002, 46, 71–89.
33. Dolhaine, H.; H o¨ nig, H. Match 2002, 46, 91–119.
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2
1
0416–10426.
0. Paul, B. J.; Martinot, T. A.; Willis, J.; Hudlicky, T. Synthesis
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3
2